Sarcomas With RAD51B Fusions Are Associated With a Heterogeneous Phenotype.

RAD51B-rearranged sarcomas are rare neoplasms that exhibit a heterogeneous morphology. To date, 6 cases have been reported, all involving the uterus, including 4 perivascular epithelioid cell tumors (PEComas) and 2 leiomyosarcomas (LMS). In this study, we describe the morphologic, immunohistochemical, and molecular features of 8 additional sarcomas with RAD51B rearrangement, including the first extrauterine example. All patients were women with a median age of 57 years at presentation. Seven tumors originated in the uterus, and one in the lower extremity soft tissue, with a median tumor size of 12 cm. Histologically, 4 tumors showed predominantly spindle cell morphology with eosinophilic fibrillary cytoplasm, with or without nuclear pleomorphism, whereas 2 tumors exhibited pleomorphic epithelioid cells, featuring clear to eosinophilic, granular cytoplasm. Two neoplasms exhibited undifferentiated cytomorphology, including one with uniform small blue round cells. All tumors showed high-grade cytologic atypia and high mitotic activity (median: 30/10 high-power fields), whereas coagulative necrosis was noted in 6 cases and lymphovascular invasion in 2. By immunohistochemistry, 2 showed myoid and melanocytic markers in keeping with PEComa, whereas 4 cases were only positive for smooth muscle markers consistent with LMS (including 3 myxoid). The remaining 2 cases had a nonspecific immunoprofile. Five cases tested by targeted RNA sequencing (Archer FusionPlex, Illumina TruSight) showed different fusion partners (HMGA2, PDDC1, and CEP170). RAD51B rearrangements were identified by FISH in the remaining 3 cases. Targeted DNA sequencing in 2 cases was negative for TSC gene alterations. Clinical outcome, available in 5 patients (median follow-up, 19 months), revealed 3 local recurrences, 2 lung metastases, and 4 deaths due to disease. Our results expand the spectrum of sarcomas with RAD51B fusions, demonstrating variable clinical presentations, morphologic spectrum, and fusion partners. These tumors have a predilection for a uterine location, with either LMS, PEComa, or undifferentiated phenotypes, and are associated with an aggressive clinical course.

Expanding the Spectrum of NR4A3 Fusion-Positive Gynecologic Leiomyosarcomas.

Recurrent gene fusions have been observed in epithelioid and myxoid variants of uterine leiomyosarcoma. PGR::NR4A3 fusions were recently described in a subset of epithelioid leiomyosarcomas exhibiting rhabdoid morphology. In this study, we sought to expand the clinical, morphologic, immunohistochemical, and genetic features of gynecologic leiomyosarcomas harboring NR4A3 rearrangements with PGR and novel fusion partners. We identified 9 gynecologic leiomyosarcomas harboring PGR::NR4A3, CARMN::NR4A3, ACTB::NR4A3, and possible SLCO5A1::NR4A3 fusions by targeted RNA sequencing. Tumors frequently affected premenopausal women, involving the uterine corpus, uterine cervix, or pelvis. All were similarly characterized by lobules of monomorphic epithelioid and/or spindled cells arranged in sheets, cords, trabeculae, and micro- and macrocysts associated with abundant myxoid matrix and hemorrhage, creating labyrinth-like or pulmonary edema-like architecture. Myogenic differentiation with frequent estrogen receptor and progesterone receptor staining and no CD10 expression characterized all tumors. All cases showed high NR4A3 RNA expression levels and NOR1 (NR4A3) nuclear staining similar to salivary gland acinic cell carcinomas and a subset of extraskeletal myxoid chondrosarcomas harboring NR4A3 rearrangements. NOR1 (NR4A3) immunohistochemistry may serve as a useful diagnostic marker of NR4A3 fusion-positive gynecologic leiomyosarcomas.

Novel Androgen Receptor Splice Variant 7 in Gynecologic Tumors.

Androgen receptor splicing variant 7 (AR-V7) is a truncated variant of the AR mRNA that may be a predictive biomarker for AR-targeted therapy. AR-V7 has been described in prostate, breast, salivary duct, and hepatocellular carcinomas as well as mammary and extra-mammary Paget disease. We report 2 gynecologic cancers occurring in the lower uterine segment and ovary and both harboring AR-V7 by targeted RNA sequencing. The uterine tumor was an undifferentiated carcinoma consisting of epithelioid cells and focally spindled cells arranged in sheets, nests, and cords associated with brisk mitotic activity and tumor necrosis. The ovarian tumor consisted of glands with cribriform and solid architecture and uniform cytologic atypia. ER and PR were positive in the ovarian tumor and negative in the uterine tumor. Both were positive for AR and negative for HER2, GATA3, and NKX3.1. DNA methylation profiling showed epigenetic similarity of the AR-V7-positive gynecologic cancers to AR-V7-positive breast cancers rather than to prostate cancers. AR-V7 may underpin rare gynecologic carcinomas with undifferentiated histology or cribriform growth reminiscent of prostatic adenocarcinoma and breast invasive ductal carcinoma.

Establishing guidelines for sentinel lymph node ultrastaging in endometrial cancer.

BACKGROUND: Many sentinel lymph node (SLN) ultrastaging protocols for endometrial cancer exist, but there is no consensus method. OBJECTIVE: This study aims to develop guidelines for size criteria in SLN evaluation for endometrial cancer, to determine whether a single cytokeratin AE1:AE3 immunohistochemical slide provides sufficient data for diagnosis, and to compare cost efficiency between current and limited ultrastaging protocols at a large tertiary care institution. METHODS: Our current SLN ultrastaging protocol consists of cutting two adjacent paraffin block sections at two levels (L1 and L2), 50 µm apart, with two slides at each level stained with hematoxylin and eosin and cytokeratin AE1:AE3 immunohistochemistry. We retrospectively reviewed digitized L1 and L2 slides of all positive ultrastaged SLNs from patients treated for endometrial cancer between January 2013 and January 2020. SLN diagnosis was defined by measuring the largest cluster of contiguous tumor cells in a single cross section: macrometastasis (>2.0 mm), micrometastasis (>0.2 to ≤2.0 mm or >200 cells), or isolated tumor cells (≤0.2 mm or ≤200 cells). Concordance between L1 and L2 results was evaluated. Cost efficiency between current (two immunohistochemical slides per block) and proposed limited (one immunohistochemical slide per block) protocols was compared. RESULTS: Digitized slides of 147 positive SLNs from 109 patients were reviewed; 4.1% of SLNs were reclassified based on refined size criteria. Complete concordance between L1 and L2 interpretations was seen in 91.8% of SLNs. A false-negative rate of 0%-0.9% in detecting micrometastasis and macrometastasis using a limited protocol was observed. Estimated charge-level savings of a limited protocol were 50% per patient. CONCLUSION: High diagnostic accuracy in SLN interpretation may be achieved using a limited ultrastaging protocol of one immunohistochemical slide per block and linear measurement of the largest cluster of contiguous tumor cells. Implementation of the proposed limited ultrastaging protocol may result in laboratory cost savings with minimal impact on health outcomes.

Prognosis of isolated tumor cells and use of molecular classification in early stage endometrioid endometrial cancer.

OBJECTIVE: We assessed the prognosis and molecular subtypes of early stage endometrioid endometrial cancer with isolated tumor cells within sentinel lymph nodes (SLNs) compared with node negative disease. METHODS: Patients diagnosed with stage IA, IB, or II endometrioid endometrial cancer and primary surgical management were identified from January 1, 2007 to December 31, 2019. All SLNs underwent ultrastaging according to the institutional protocol. Patients with cytokeratin positive cells, micrometastases, and macrometastases were excluded. Clinical, pathology, and molecular subtype data were reviewed. RESULTS: Overall, 1214 patients with early stage endometrioid endometrial cancer met the inclusion criteria, of whom 1089 (90%) had node negative disease and 125 (10%) had isolated tumor cells. Compared with node negative disease, the presence of isolated tumor cells had a greater association with deep myometrial invasion, lymphovascular space invasion, receipt of adjuvant therapy, and adjuvant chemotherapy with or without radiation (p<0.01). There was no significant difference in survival rates between patients with isolated tumor cells and node negative disease (3 year progression free survival rate 94% vs 91%, respectively, p=0.21; 3 year overall survival rate 98% vs 96%, respectively, p=0.45). Progression free survival did not significantly differ among patients with isolated tumor cells who received no adjuvant therapy or chemotherapy with or without radiation (p=0.31). There was no difference in the distribution of molecular subtypes between patients with isolated tumor cells (n=28) and node negative disease (n=194; p=0.26). Three year overall survival rates differed significantly when stratifying the entire cohort by molecular subtype (p=0.04). CONCLUSIONS: Patients with isolated tumor cells demonstrated less favorable uterine pathologic features and received more adjuvant treatment with similar survival compared with patients with nodenegative disease. Among the available data, molecular classification did not have a significant association with the presence of isolated tumor cells, although copy number-high status was a poor prognostic indicator in early stage endometrioid endometrial cancer.

Expanding the molecular spectrum of gene fusions in endometrial stromal sarcoma: Novel subunits of the chromatin remodeling complexes PRC2 and NuA4/TIP60 as alternative fusion partners.

Endometrial stromal sarcomas (ESS) are morphologically and molecularly heterogeneous. We report novel gene fusions (EPC1::EED, EPC1::EZH2, ING3::PHF1) identified by targeted RNA sequencing in five cases. The ING3::PHF1-fusion positive ESS presented in a 58-year-old female as extrauterine mesocolonic, ovarian masses, and displayed large, monomorphic ovoid-to-epithelioid cells arranged in solid sheets. The patient remained alive with disease 13 months after surgery. The three ESS with EPC1::EED occurred in the uterine corpus in patients with a median age of 58 years (range 27-62 years). One tumor showed a uniform epithelioid nested morphology, while the other two were composed of monomorphic spindle cells in fascicles with elevated mitotic figures, focal tumor cell necrosis, and lymphovascular invasion. At a median follow-up of 20 months, two patients developed local recurrence, including one with concomitant distant metastasis, while one patient remained free of disease. All three patients were alive at the last follow-up. The EPC1::EZH2-fusion positive ESS presented in a 52-year-old female in the uterus, and displayed uniform spindled cells arranged in short fascicles, with focally elevated mitotic activity but without necrosis. The patient remained free of disease 3 months after surgery. All cases were diffusely positive for CD10; four diffusely express estrogen and progesterone receptors. Our study expands the molecular spectrum of EPC1 and PHF1-related gene fusions in ESS to include additional novel subunits of the PRC2 and/or NuA4/TIP60 complexes. These cases displayed a monomorphic epithelioid or spindled phenotype, spanning low-grade and high-grade cytomorphology, all expressing CD10 and commonly ER and PR, and are prone to local and/or distant spread.

Direct-to-Implant vs Tissue Expander Placement in Immediate Breast Reconstruction: A Prospective Cohort Study.

BACKGROUND: Direct-to-implant (DTI) breast reconstruction after mastectomy has gained increasing popularity. While concerns over ischemic complications related to tension on the mastectomy flap persist, newer techniques and technologies have enhanced safety of this technique. OBJECTIVES: To compare clinical and patient-reported outcomes of DTI and two-stage tissue expander (TE) reconstruction. METHODS: A prospective cohort design was utilized to compare the incidence of reconstructive failure among patients undergoing DTI and TE reconstruction via unadjusted bivariate and adjusted multivariable logistic regression analyses. Secondary clinical outcomes of interest included specific complications requiring intervention (infection, seroma, hematoma, mastectomy flap necrosis, incisional dehiscence, device exposure) and time to final drain removal. Patient-reported outcomes (PROs) via BREAST-Q were also compared. RESULTS: A total of 134 patients (257 breasts) underwent DTI reconstruction and 222 patients (405 breasts) received TEs. DTI patients were significantly younger with lower BMIs, less diabetes, hypertension, and smoking, and smaller breast sizes, and underwent more nipple-sparing mastectomies with prepectoral reconstructions. Rates of any complication (18% DTI vs 24% TE, p=0.047), reconstructive failure (5.1% vs 12%, p=0.004), and seroma (3.9% vs 11%, p<0.001) were significantly lower in the DTI cohort on unadjusted analyses; however, there were no significant differences in adjusted regressions. Patient-reported satisfaction with breasts, psychosocial well-being, and sexual well-being were more substantively improved with DTI reconstruction. CONCLUSIONS: Prepectoral DTI reconstruction is a viable option for post-mastectomy reconstruction in carefully selected patients, with no significant increase in reconstructive failure or other complications.

High-Grade Sarcomas with Myogenic Differentiation Harboring Hotspot PDGFRB Mutations.

PDGFRB-activating mutations have been reported in pediatric myofibroma and myofibromatosis. However, recurrent gain-of-function PDGFRB mutations have not been documented in sarcomas with myogenic differentiation. Driven by occasional sarcomas harboring PDGFRB mutations, we investigated their prevalence and clinicopathologic and genomic features in a large cohort of sarcomas. An institutional targeted DNA next-generation sequencing database was searched for sarcomas with myogenic differentiation harboring hotspot PDGFRB gene alterations. Among 3300 patients with sarcomas, 21 (0.6%) patients were identified (17 women, 4 men) with an age range of 35 to 88 years. The site distribution included 13 gynecologic tract (12 uteri, 1 vagina), 4 bone and soft tissue, and 4 viscera. All except 1 were high grade. Most patients were diagnosed as sarcomas with myogenic differentiation based on partial staining for 1 or more muscle markers, whereas 6 were labeled as leiomyosarcoma (LMS). Most tumors showed monomorphic spindle morphology, with either heterogeneous features of myofibroblastic and smooth muscle differentiation or an undifferentiated phenotype. Hormone receptors were negative in all uterine cases. PDGFRB immunostaining in all cases tested was strong and diffuse, whereas PDGFRA was negative/focal. The most frequent PDGFRB mutations were exon 12 (43%), exon 14 (N666K/S/T) (38%), and exon 18 (D850Y/H/V or insertion/deletion) (19%). The most frequent co-existing genetic alterations (26% to 37%) occurred in CDKN2A/B, TP53, TERT, and MED12. Moreover, PDGFRB-mutant sarcomas had an overall distinct genomic landscape compared with both uterine and soft tissue LMS control groups. These tumors were associated with a highly aggressive clinical course, with frequent distant metastases (81%) and death (76%), regardless of anatomic location, and worse overall survival compared with the 2 LMS control groups. This is the first study documenting recurrent hotspot PDGFRB alterations in high-grade sarcomas, which show a predilection for uterine location and myogenic differentiation that fall short of the diagnostic criteria for LMS. Further studies are needed to investigate the therapeutic potential of kinase inhibitors in this group of tumors.

Molecular-Based Immunohistochemical Algorithm for Uterine Leiomyosarcoma Diagnosis.

The morphologic assessment of uterine leiomyosarcoma (LMS) may be challenging, and diagnostic immunohistochemical (IHC) analysis is currently lacking. We evaluated the genomic landscape of 167 uterine LMS by targeted next-generation sequencing (NGS) to identify common genomic alterations. IHC analyses corresponding to these genomic landmarks were applied to a test cohort of 16 uterine LMS, 6 smooth muscle tumors of uncertain malignant potential (STUMP), and 6 leiomyomas with NGS data and a validation cohort of 8 uterine LMS, 12 STUMP, 21 leiomyomas and leiomyoma variants, 7 low-grade endometrial stromal sarcomas, and 2 diagnostically challenging uterine smooth muscle tumors. IHC results were individually interpreted by 3 pathologists blinded to NGS data. Overall, 94% of LMS showed ≥1 genomic alteration involving TP53, RB1, ATRX, PTEN, CDKN2A, or MDM2, with 80% showing alterations in ≥2 of these genes. In the test cohort, an initial panel of p53, Rb, PTEN, and ATRX was applied, followed by a panel of DAXX, MTAP, and MDM2 in cases without abnormalities. Abnormal p53, Rb, PTEN, and ATRX IHC expression was seen in 75%, 88%, 44%, and 38% of LMS, respectively, in the test cohort. Two or more abnormal IHC results among these markers were seen in 81% of LMS. STUMPs demonstrated only 1 IHC abnormality involving these markers. No IHC abnormalities were seen in leiomyomas. In the validation cohort, abnormal p53, Rb, and PTEN IHC results were seen in LMS, whereas rare STUMP or leiomyomas with bizarre nuclei showed IHC abnormalities involving only 1 of the markers. Abnormalities in ≥2 markers were present in both diagnostically challenging smooth muscle tumors, confirming LMS. Concordance was excellent among pathologists in the interpretation of IHC (κ = 0.97) and between IHC and NGS results (κ = 0.941). Uterine LMS exhibit genomic landmark alterations for which IHC surrogates exist, and a diagnostic algorithm involving molecular-based IHC may aid in the evaluation of unusual uterine smooth muscle tumors.

DNA Methylation Signature of Synchronous Endometrioid Endometrial and Ovarian Carcinomas.

Next-generation sequencing (NGS) studies have demonstrated that co-occurring sporadic endometrioid endometrial carcinoma (EEC) and endometrioid ovarian carcinoma (EOC) are clonally related, suggesting that they originate from a single primary tumor. Despite clonality, synchronous EEC and EOC when diagnosed at early stage behave indolently, similar to isolated primary EEC or isolated primary EOC. In the present study, we compared the DNA methylation signatures of co-occurring EEC and EOC with those of isolated primary EEC and isolated primary EOC. We also performed targeted NGS to assess the clonal relatedness of 7 co-occurring EEC and EOC (4 synchronous EEC and EOC and 3 metastatic EEC based on pathologic criteria). NGS confirmed a clonal relationship in all co-occurring EEC and EOC. DNA methylation profiling showed distinct epigenetic signatures of isolated primary EEC and isolated primary EOC. Endometrial tumors from co-occurring EEC and EOC clustered with isolated primary EEC while their ovarian counterparts clustered with isolated primary EOC. Three co-occurring EEC and EOC cases with peritoneal lesions showed a closer epigenetic signature and copy number variation profile between the peritoneal lesion and EOC than EEC. In conclusion, synchronous sporadic EEC and EOC are clonally related but demonstrate a shift in DNA methylation signatures between ovarian and endometrial tumors as well as epigenetic overlap between ovarian and peritoneal tumors. Our results suggest that tumor microenvironment in the ovary may play a role in epigenetic modulation of metastatic EEC.

High-Grade Endometrial Stromal Sarcomas With YWHAE::NUTM2 Gene Fusion Exhibit Recurrent CDKN2A Alterations and Absence of p16 Staining is a Poor Prognostic Marker.

High-grade endometrial stromal sarcomas (HGESSs) are aggressive uterine tumors harboring oncogenic fusion proteins. We performed a molecular study of 36 HGESSs with YWHAE::NUTM2 gene fusion, assessing co-occurring genetic events, and showed that these tumors frequently harbor recurrent events involving the CDKN2A locus on chromosome 9p. Using array-based copy number profiling and CDKN2A fluorescence in situ hybridization, we identified homozygous and hemizygous deletions of CDKN2A in 18% and 14% of tumors (n = 22 analyzed), respectively. While all YWHAE-rearranged HGESSs with retained disomy for CDKN2A were immunohistochemically positive for p16INK4 (p16), all tumors with homozygous deletion of CDKN2A showed complete absence of p16 staining. Of the 2 tumors with a hemizygous deletion of CDKN2A, 1 showed diffuse and strong p16 positivity, whereas the other showed complete absence of staining. In the p16-negative case, we did not find intragenic mutations or DNA promoter methylation to explain the p16 protein loss, implicating other mechanisms in the regulation of protein expression. In our cohort, subclonal or complete absence of p16 staining was associated with worse overall survival compared with positive p16 staining (1-year overall survival: 28.6% vs 90.7%, respectively; n = 32; P < .001), with all 7 patients in the p16-negative group having succumbed to their disease within 2 years of diagnosis. Our results suggested CDKN2A alterations as a cooperative driver of tumorigenesis in a subset of HGESSs with the YWHAE::NUTM2 gene fusion and showed p16 to be a potential prognostic marker.

The Association between Breast Cancer Related Lymphedema and Area Deprivation Index.

BACKGROUND: Lymphedema affects up to 34% of patients after breast cancer treatment but remains underdiagnosed and undertreated. Here, we use area deprivation index (ADI), a measure of neighborhood socioeconomic disadvantage, to determine how socioeconomic status may affect risk for and diagnosis of breast cancer-related lymphedema. METHODS: Records of patients who underwent surgical treatment of breast cancer between 2017-2020 were examined. Patients' nine-digit ZIP codes were utilized to determine their deprivation level as a national ADI percentile, and those fitting into the most and least deprived quartiles were compared with evaluate lymphedema risk factors and incidence. RESULTS: A total of 1,333 breast cancer patients were included, 812 (61%) of whom resided within the most disadvantaged ADI quartile nationally, and 521 within the least disadvantaged quartile. The most deprived group had higher rates of diabetes, obesity, and regional breast cancer, and received more extensive surgeries (7.5% modified radical mastectomy vs 1.9%, p < 0.001) and chemotherapy compared with the least disadvantaged quartile. The most disadvantaged cohort were more often at extreme risk of lymphedema utilizing the Risk Assessment Tool Evaluating Lymphedema Risk (9.1% versus 2.5%, p < 0.001); however, the incidence of lymphedema diagnoses was not significantly higher (13% vs 12%, p > 0.9). Logistic regression showed that the most deprived ADI quartile had 44% lower odds of a lymphedema diagnosis in comparison to the least deprived quartile. CONCLUSION: Residing in more socioeconomically disadvantaged neighborhoods is associated with lower odds of a lymphedema diagnosis, despite higher rates of risk factors for lymphedema, suggesting significant underdiagnosis in this population.

Mullerian adenosarcoma: clinicopathologic and molecular characterization highlighting recurrent BAP1 loss and distinctive features of high-grade tumors.

Mullerian adenosarcoma is an uncommon mesenchymal tumor of the gynecologic tract. Most cases are low-grade, while high-grade adenosarcomas are rare and not well studied. Herein, we characterize the clinicopathologic and molecular features of 27 adenosarcomas of gynecologic origin, enriched for high-grade tumors subjected to targeted panel sequencing. Sarcomatous overgrowth was more frequently seen in high-grade compared to low-grade tumors (12/17, 71%, vs 1/10, 10%, p = 0.004) and heterologous elements were exclusive to high-grade cases (n = 7, p = 0.03). All deaths were from high-grade disease (advanced primary, n = 2, or recurrence, n = 5). Genetic alterations specific to high-grade adenosarcomas have known associations with chromosome instability, including TP53 mutations (n = 4) and amplifications of MDM2 (n = 2) and CCNE1 (n = 2). Somatic ATRX frameshift mutations were found in 2 patients with high-grade recurrences following a primary low-grade adenosarcoma and ATRX deletion in 1 high-grade adenosarcoma with an adjacent low-grade component. The fraction of genome altered by copy number alterations was significantly higher in high-grade compared to low-grade adenosarcomas (P = 0.001). Other recurrent genetic alterations across the entire cohort included BAP1 homozygous deletions (n = 4), DICER1 mutations (n = 4), ARID1A mutations (n = 3), TERT promoter mutations (n = 2) and amplification (n = 1), as well as alterations involving members of the PI3K and MAPK signaling pathways. One tumor harbored an ESR1-NCOA3 fusion and another had an MLH1 homozygous deletion. Immunohistochemical analysis for BAP1 revealed loss of nuclear expression in 6/24 (25%) cases, including all four tumors with BAP1 deletions. Notably, out of 196 mesenchymal neoplasms of gynecologic origin, BAP1 homozygous deletion was only found in adenosarcomas (P = 0.0003). This study demonstrates that high-grade adenosarcomas are heterogeneous at the molecular level and are characterized by genomic instability and TP53 mutations; ATRX loss may be involved in high-grade transformation of low-grade adenosarcoma; and BAP1 inactivation appears to be a specific pathogenic driver in a subset of adenosarcomas.

ESR1 hotspot mutations in endometrial stromal sarcoma with high-grade transformation and endocrine treatment.

High-grade endometrial stromal sarcomas (HGESSs) are more aggressive and have higher rates of resistance to endocrine therapy than low-grade endometrial stromal sarcomas (LGESSs). The pathogenesis of hormonal resistance in these lesions has yet to be defined. Here we sought to histologically and genetically characterize 3 LGESSs and their recurrences that underwent histologic high-grade transformation following endocrine therapy. For this, DNA from primary tumors and select subsequent recurrences were subject to massively parallel sequencing targeting 468 cancer-related genes. Somatic mutation analyses were performed using validated bioinformatics methods. In addition, RNA from each case was evaluated for the presence of gene fusions using targeted RNA-sequencing. All patients initially presented with LGESS, developed HGESS recurrences, and received at least 2 lines of hormonal suppressive therapy. Gene fusions classically described as associated with LGESS were identified in all 3 cases, including JAZF1-PHF1, EPC1-PHF1 and JAZF1-SUZ12 fusions for Cases 1, 2 and 3, respectively. Targeted sequencing analysis revealed that none of the primary LGESS, however the HGESS recurrences of Cases 1 and 3, and the LGESS and HGESS recurrences of Case 2 post endocrine treatment harbored ESR1 p.Y537S hotspot mutations. These ESR1 ligand-binding domain mutations have been found as a mechanism of acquired endocrine resistance in breast cancer. Also, a reduction in estrogen receptor (ER) expression was observed in recurrences. Our findings suggest that the ESR1 p.Y537S hotspot mutation in LGESS with histologic high-grade transformation may be associated with endocrine resistance in these lesions. Furthermore, our data suggest that genetic analyses may be performed in recurrent LGESS following hormonal therapy, development of high-grade morphology, and/or altered/diminished ER expression.

TSC2-mutant uterine sarcomas with JAZF1-SUZ12 fusions demonstrate hybrid features of endometrial stromal sarcoma and PEComa and are responsive to mTOR inhibition.

Uterine perivascular epithelioid cell tumor (PEComa) is a rare mesenchymal neoplasm that occasionally shares morphologic and immunohistochemical overlap with low- and high-grade endometrial stromal sarcoma (LGESS and HGESS). In this study, we sought to characterize the clinical, morphologic, genetic, and epigenetic features of five uterine sarcomas that display histologic features of LGESS, HGESS, and PEComa. All tumors demonstrated epithelioid cells often associated with a low-grade spindled component resembling LGESS, with both regions expressing CD10, ER, PR, variable HMB45, and Melan-A immunoreactivity, and strong cathepsin K and pS6 expression. Targeted massively parallel sequencing analysis revealed the presence of somatic TSC2 mutations in all five cases, of which four harbored concurrent or consecutive JAZF1-SUZ12 gene fusions. Unsupervised hierarchical clustering analysis of methylation profiles of TSC2-mutant uterine sarcomas (n = 4), LGESS (n = 10), and HGESS (n = 12) demonstrated two clusters consisting of (1) all LGESS and TSC2-mutant uterine sarcomas and (2) all HGESS. KEGG pathway analysis detected methylation differences in genes involved in PI3K/AKT, calcium, and Rap1 signaling. TSC2-mutant uterine sarcomas were responsive to hormone suppression, and mTOR inhibition demonstrated clinical benefit in four patients with these neoplasms. Our results suggest that these tumors represent histologically distinctive LGESS with TSC2 mutations. TSC2 mutations and JAZF1-SUZ12 fusion may help diagnose these tumors and possibly direct effective treatment.

The impact of the COVID-19 pandemic on alloplastic breast reconstruction: An analysis of national outcomes.

BACKGROUND: Immediate alloplastic breast reconstruction shifted to the outpatient setting during the COVID-19 pandemic to conserve inpatient hospital beds while providing timely oncologic care. We examine the National Surgical Quality Improvement Program (NSQIP) database for trends in and safety of outpatient breast reconstruction during the pandemic. METHODS: NSQIP data were filtered for immediate alloplastic breast reconstructions between April and December of 2019 (before-COVID) and 2020 (during-COVID); the proportion of outpatient procedures was compared. Thirty-day complications were compared for noninferiority between propensity-matched outpatients and inpatients utilizing a 1% risk difference margin. RESULTS: During COVID, immediate alloplastic breast reconstruction cases decreased (4083 vs. 4677) and were more frequently outpatient (31% vs. 10%, p < 0.001). Outpatients had lower rates of smoking (6.8% vs. 8.4%, p = 0.03) and obesity (26% vs. 33%, p < 0.001). Surgical complication rates of outpatient procedures were noninferior to propensity-matched inpatients (5.0% vs. 5.5%, p = 0.03 noninferiority). Reoperation rates were lower in propensity-matched outpatients (5.2% vs. 8.0%, p = 0.003). CONCLUSION: Immediate alloplastic breast reconstruction shifted towards outpatient procedures during the COVID-19 pandemic with noninferior complication rates. Therefore, a paradigm shift towards outpatient reconstruction for certain patients may be safe. However, decreased reoperations in outpatients may represent undiagnosed complications and warrant further investigation.

Primary characteristics and outcomes of newly diagnosed low-grade endometrial stromal sarcoma.

OBJECTIVE: To assess potential predictive variables for nodal metastasis and survival outcomes in patients with newly diagnosed, low-grade endometrial stromal sarcoma. METHODS: We performed a single-institution, retrospective analysis of consecutive patients with newly diagnosed, low-grade endometrial stromal sarcoma who presented between January 1, 1980 and December 31, 2019 and underwent hysterectomy at our institution or presented within 3 months of primary surgery elsewhere before recurrence. Patients who presented to our institution only at recurrence were excluded. Patients with <3 months of follow-up were excluded from survival analyses. RESULTS: We identified 127 consecutive patients for analysis. Median age at diagnosis was 48 years (range 19-88 years); 91 (74.6%) of 127 were pre-menopausal; and 74 (58.3%) of 127 had uterine-confined, stage I tumors. Of 56 patients (44.1%) who underwent lymph node sampling, 10 (17.9%) had nodal metastasis. Of the 10 with nodal metastasis, 1 (10%) did not have lymphadenopathy or extra-uterine disease, 4 (40%) had lymphadenopathy only, 1 (10%) had extra-uterine disease only, and 4 (40%) had both. Among the 29 patients without apparent extra-uterine disease or gross lymphadenopathy, there was one occult lymph node metastasis (3.4%). Gross lymphadenopathy at time of surgery was predictive for lymph node metastasis (p<0.001). Median follow-up was 69 months (range 4-336) for the 95 patients included in the survival analyses. The 5-year progression-free survival and disease-specific survival rates were 79.8% and 90.8%, respectively. Patients with stage I tumors had longer progression-free survival than those with stage II-IV disease (p<0.001); there was no difference in disease-specific survival (p=0.63). Post-operative observation versus adjuvant therapy with hormone blockade or radiation therapy did not result in progression-free survival differences for stage I or completely resected stage II-IV disease (p=0.50 and p=0.81, respectively). Similarly, there was no disease-specific survival difference for completely resected stage II-IV disease (p=0.3). CONCLUSIONS: Lymph node dissection in patients with low-grade endometrial stromal sarcoma should be reserved for those with clinically suspicious lymphadenopathy. Disease stage correlated with progression-free survival but not disease-specific survival. Post-operative therapy did not improve progression-free survival or disease-specific survival.

Cognitive Development in Lambdoid Craniosynostosis: A Systematic Review and Meta-Analysis.

OBJECTIVE: Lambdoid craniosynostosis affects approximately 1 in 33 000 live births per year, and surgical correction is often sought in order to achieve normocephaly and allow for adequate brain growth. However, the effects of lambdoid synostosis and its treatment on cognitive development are unknown. DESIGN: Systematic review and meta-analysis. PATIENTS, PARTICIPANTS: A systematic review of Ovid Medline, Embase, Web of Science, Scopus, Cochrane Central Register of Controlled Trials, and Clinicaltrials.gov was conducted in January 2022. Included studies assessed cognitive development of patients with nonsyndromic unilateral lambdoid craniosynostosis. MAIN OUTCOME MEASURES: Results of developmental tests were compared to normative data or controls to generate Hedges' g for meta-analysis. RESULTS: Nine studies met the inclusion criteria. Meta-analysis of 3 studies describing general cognition showed that cases scored significantly lower than their peers, but within 1 standard deviation (g = 0.37, 95% CI [-0.64, -0.10], P = .01). Meta-analysis of verbal and psychomotor development showed no significant differences in children with lambdoid synostosis. Studies were of fair quality and had moderate-to-high heterogeneity. CONCLUSIONS: Patients with lambdoid craniosynostosis may score slightly below average on tests of general cognition in comparison to normal controls, but results in other domains are variable. Analyses were limited by small sample sizes. Multidisciplinary care and involvement of a child psychologist may be helpful in identifying areas of concern and providing adequate scholastic support. Further research recruiting larger cohorts will be necessary to confirm these findings and extend them to other developmental domains such as attention and executive function.

Effect of Veau Class on Levator Veli Palatini Muscle Composition.

OBJECTIVE: To examine levator veli palatini muscle composition in patients with nonsyndromic cleft palate and investigate the impact of Veau class. DESIGN: Prospective cohort study. SETTING: Tertiary care academic hospital. PATIENTS/PARTICIPANTS: Thirteen patients with nonsyndromic cleft palate were recruited. INTERVENTIONS: During primary palatoplasty, a sample of levator veli palatini muscle was excised and prepared for histological analysis. MAIN OUTCOME MEASURES: Fat and collagen content were determined utilizing Oil Red and Sirius red stains, respectively, while muscle fiber cross-sectional areas were calculated from H&E-stained samples, with analysis using histomorphometric methods. Immunofluorescent staining of myosin heavy chain isoforms was performed. RESULTS: Patients underwent repair at 10.8 months of age (interquartile range [IQR] 10.2-12.9). Fat content of the levator veli palatini muscle was low in both groups, ranging from 0% to 5.2%. Collagen content ranged from 8.5% to 39.8%; neither fat nor collagen content showed an association with Veau classes. Mean muscle fiber cross-sectional area decreased with increasing Veau class, from 808 µm2 (range 692-995 µm2) in Veau II to 651 µm2 (range 232-750 µm2) in Veau III (P = .02). There was also a nonsignificant decrease in proportion of type I muscle fibers with increasing Veau class (44.3% [range 31.4%-84.4%] in Veau II vs 35.3% [range 17.4%-61.3%] in Veau III). CONCLUSIONS: Muscle fiber area in levator veli palatini muscles decreases in Veau III clefts in comparison to Veau II. The impact of these differences in velopharyngeal dysfunction requires further analysis of a larger cohort.

National Outcomes of Prophylactic Lymphovenous Bypass during Axillary Lymph Node Dissection.

BACKGROUND: Breast cancer treatment, including axillary lymph node excision, radiation, and chemotherapy, can cause upper extremity lymphedema, increasing morbidity and health care costs. Institutions increasingly perform prophylactic lymphovenous bypass (LVB) at the time of axillary lymph node dissection (ALND) to reduce the risk of lymphedema but reports of complications are lacking. We examine records from the American College of Surgeons (ACS) National Surgery Quality Improvement Program (NSQIP) database to examine the safety of these procedures. METHODS: Procedures involving ALND from 2013 to 2019 were extracted from the NSQIP database. Patients who simultaneously underwent procedures with the Current Procedural Terminology (CPT) codes 38999 (other procedures of the lymphatic system), 35201 (repair of blood vessel), or 38308 (lymphangiotomy) formed the prophylactic LVB group. Patients in the LVB and non-LVB groups were compared for differences in demographics and 30-day postoperative complications including unplanned reoperation, deep vein thrombosis (DVT), wound dehiscence, and surgical site infection. Subgroup analysis was performed, controlling for extent of breast surgery and reconstruction. Multivariate logistic regression was performed to identify predictors of reoperation. RESULTS: The ALND without LVB group contained 45,057 patients, and the ALND with LVB group contained 255 (0.6%). Overall, the LVB group was associated with increased operative time (288 vs. 147 minutes, p < 0.001) and length of stay (1.7 vs. 1.3 days, p < 0.001). In patients with concurrent mastectomy without immediate reconstruction, the LVB group had a higher rate of DVTs (3.0 vs. 0.2%, p = 0.009). Reoperation, wound infection, and dehiscence rates did not differ across subgroups. Multivariate logistic regression showed that LVB was not a predictor of reoperations. CONCLUSION: Prophylactic LVB at time of ALND is a generally safe and well-tolerated procedure and is not associated with increased reoperations or wound complications. Although only four patients in the LVB group had DVTs, this was a significantly higher rate than in the non-LVB group and warrants further investigation.