In Vivo Microstructure Imaging in Oropharyngeal Squamous Cell Carcinoma Using the Random Walk With Barriers Model.

BACKGROUND: Apparent diffusion coefficient is not specifically sensitive to tumor microstructure and therapy-induced cellular changes. PURPOSE: To investigate time-dependent diffusion imaging with the short-time-limit random walk with barriers model (STL-RWBM) for quantifying microstructure parameters and early cancer cellular response to therapy. STUDY TYPE: Prospective. POPULATION: Twenty-seven patients (median age of 58 years and 7.4% of females) with p16+/p16- oropharyngeal/oral cavity squamous cell carcinomas (OPSCC/OCSCC) underwent MRI scans before therapy, of which 16 patients had second scans at 2 weeks of the 7-weeks chemoradiation therapy (CRT). FIELD STRENGTH/SEQUENCE: 3-T, diffusion sequence with oscillating gradient spine echo (OGSE) and pulse gradient spin echo (PGSE). ASSESSMENT: Diffusion weighted images were acquired using OGSE and PGSE. Effective diffusion times were derived for the STL-RWBM to estimate free diffusion coefficient D0 , volume-to-surface area ratio of cellular membranes V/S, and cell membrane permeability κ. Mean values of these parameters were calculated in tumor volumes. STATISTICAL TESTS: Tumor microstructure parameters were compared with clinical stages of p16+ I-II OPSCC, p16+ III OPSCC, and p16- IV OCSCC by Spearman's rank correlation and with digital pathological analysis of a resected tissue sample. Tumor microstructure parameter responses during CRT in the 16 patients were assessed by paired t-tests. A P-value of <0.05 was considered statistically significant. RESULTS: The derived effective diffusion times affected estimated values of V/S and κ by 40%. The tumor V/S values were significantly correlated with clinical stages (r = 0.47) as an increase from low to high clinical stages. The in vivo estimated cell size agreed with one from pathological analysis of a tissue sample. Early tumor cellular responses showed a significant increase in D0 (14%, P = 0.03) and non-significant increases in κ (56%, P = 0.6) and V/S (10%, P = 0.1). DATA CONCLUSION: Effective diffusion time estimation might impact microstructure parameter estimation. The tumor V/S was correlated with OPSCC/OCSCC clinical stages. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY STAGE: 1.

Highly Recurrent IDH1 Mutations in Prostate Cancer With Psammomatous Calcification.

Prostate cancer is a heterogeneous disease with several well-recognized morphologic subtypes and histologic variants-subsets of which are enriched for or associated with specific genomic alterations. Herein, we report a cohort of 4 unique prostate cancers characterized by intratumoral psammomatous calcification-which we have termed prostate cancer with psammomatous calcification (PCWPC). Clinicopathologic review demonstrates that PCWPCs are high-grade (grade group ≥3) tumors that involve the anterior prostate, and integrative targeted next-generation sequencing reveals recurrent hotspot IDH1 mutations. This morphology-molecular correlation is independently confirmed in The Cancer Genome Atlas prostatic adenocarcinoma cohort, with 3 of the 5 IDH1-mutant prostate cancers showing psammomatous calcification (rφ = 0.67; Fisher exact test, P < .0001). Overall, these findings suggest that PCWPC represents a novel subtype of prostate cancer enriched for an anterior location and the presence of hotspot IDH1 mutations. Recognition of these unique morphologic features could help identify IDH1-mutant prostate cancer cases retrospectively and prospectively-facilitating future large research studies and enabling clinical trial enrollment and precision medicine approaches for patients with advanced and/or aggressive disease.

Unusual Ovarian Tumors With Endometrioid Proliferations Co-Expressing Estrogen Receptor and CDX-2 Arising in Cystadenofibromatous Background: Report of 3 Cases.

This report describes 3 cases of ovarian tumors with unusual glandular proliferations co-expressing estrogen receptor and CDX-2 by immunohistochemistry set in cystadenofibromatous background. Targeted next-generation sequencing was performed on the cyst lining epithelium and glandular proliferations for all cases; CTNNB1 mutations were detected in the glandular proliferations of all neoplasms. The cyst lining of case 1 demonstrated a different CTNNB1 mutation from the matched glandular proliferation. No mutations were detected in the cyst lining from case 2. The cyst lining and glandular proliferation for case 3 harbored identical ATM and PIK3CA mutations with an additional CTNNB1 mutation in the glandular proliferation. To our knowledge, this is the first reported series of endometrioid proliferations with co-expression of estrogen receptor and CDX-2 in cystadenofibromatous background.

Endometrial, Ovarian, and Peritoneal Involvement by Endometrioid Carcinoma, Yolk Sac Tumor, and Endometriosis: Molecular Evidence for a Shared Precursor.

Recent studies have provided molecular confirmation that a subset of yolk sac tumors is somatically derived. Somatically derived yolk sac tumors are typically diagnosed in older women and are often seen adjacent to epithelial proliferations (such as endometriosis or endometrioid carcinoma) with which they share mutations. Here, we present a case of a postmenopausal woman with a yolk sac tumor and endometriosis in the right ovary, endometriosis with glandular crowding and reactive changes in the left ovary, endometrial endometrioid carcinoma, and yolk sac tumor involving the serosa of the colon. Targeted next-generation sequencing of these five tumor components demonstrated identical mutations in PTEN (p.R130G), PIK3CA (p.G1049S), FGFR2 (p.S252W), and FBXW7 (p.R689Q), suggesting that all components arose from a common precursor. The endometrial endometrioid carcinoma harbored additional exclusive mutations involving PIK3CA (p.H1048R) and CTNNB1 (p.S37F).

Malignant Neoplasms of the Penis with Radiologic and Pathologic Correlation.

Penile malignancy is the third most common male-specific genitourinary malignancy, with squamous cell carcinoma representing the most common histologic type. Squamous cell carcinoma is an epithelial malignancy, frequently developing from the mucosal surfaces of the foreskin, glans, and coronal sulcus and manifesting as a distal infiltrative or ulcerated mass. This typically occurs in men from the 6th to 8th decades of life, and risk factors include human papillomavirus, phimosis, presence of foreskin and poor hygiene, chronic inflammatory conditions such as lichen sclerosus, trauma, and smoking. Primary urethral malignancies including urothelial carcinoma and adenocarcinoma can occur but may lack this distal predilection. Sarcoma, melanoma, leukemia or lymphoma, and metastatic disease are less common sources of penile malignancy. Because of the sensitive nature of penile malignancies, there may be delays in seeking care and in subsequent diagnosis. Recently, the staging guidelines for penile cancer have been updated concurrently with a shift toward more penile-preserving therapies, which have led to a larger role of imaging in diagnosis, staging, and treatment planning for penile malignancies. A variety of imaging modalities may play a role in the identification and staging of penile malignancy, including an increased use of MRI for local staging of tumors, CT and PET/CT for identification of nodal and distant disease, and US for image-guided biopsy. The authors discuss an imaging approach to a spectrum of penile malignancies, with an emphasis on radiologic and pathologic correlation and how knowledge of normal tissue types and anatomic structures can aid in the diagnosis and staging of these tumors. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

p53 null phenotype is a "positive result" in urothelial carcinoma in situ.

The concept of a "p53 null phenotype" (complete loss of staining) is well-recognized in the gynecologic pathology literature, implicitly reflecting that this staining pattern represents a TP53 mutation. However, in the genitourinary pathology literature, a p53 null phenotype has only been addressed regarding the prognosis of invasive urothelial carcinoma, and not as a diagnostic biomarker for urothelial carcinoma in situ (CIS). Herein, 25 cases of urothelial carcinoma in situ [diagnoses made on hematoxylin and eosin (H&E) stained sections] showing null pattern p53 staining were retrieved from 22 different patients (16 males and 6 females, age range 52-85 years; average 69.6 years), most commonly showing large cell pleomorphic pattern morphology. One representative tissue block per case was selected for next-generation DNA sequencing (NGS). All 21 cases (100%) passing quality control for NGS showed at least 1 TP53 mutation (majority nonsense or frameshift mutations), including 3 cases with 2 mutations and 3 cases with 3 mutations. Three patients with multiple available samples harbored 1 or more shared TP53 mutations at 2 different time points, indicating clonality of the temporally distinct lesions. Additionally, 2 patients had an additional unique TP53 mutation at a later time point, suggesting intratumoral heterogeneity and/or temporal clonal evolution. While urothelial CIS remains an H&E diagnosis in most cases, a p53 immunostain may be useful in a subset of challenging cases. This study demonstrates that a p53 null phenotype represents an aberrant result in urothelial CIS with supportive molecular analysis showing a previously unknown level of complexity for TP53 mutations among these noninvasive lesions. Adequate recognition of the p53 null phenotype as a "biologically supportive result", similar to strong and diffuse staining with p53, is important and may warrant a formal consensus statement for recommended p53 reporting (i.e., "wild type" versus "aberrant or mutant").

Genomic evidence suggests that cutaneous neuroendocrine carcinomas can arise from squamous dysplastic precursors.

Merkel cell carcinoma (MCC) is an aggressive cutaneous neuroendocrine carcinoma without a known dysplastic precursor. In some cases, MCC is associated with SCCIS in the overlying epidermis; however, the MCC and SCCIS populations display strikingly different morphologies, and thus far a relationship between these components has not been demonstrated. To better understand the relationship between these distinct tumor cell populations, we evaluated 7 pairs of MCC-SCCIS for overlapping genomic alterations by cancer profiling panel. A subset was further characterized by transcriptional profiling and immunohistochemistry. In 6 of 7 MCC-SCCIS pairs there was highly significant mutational overlap including shared TP53 and/or RB1 mutations. In some cases, oncogenic events previously implicated in MCC (MYCL gain, MDM4 gain, HRAS mutation) were detected in both components. Although FBXW7 mutations were enriched in MCC, no gene mutation was unique to the MCC component across all cases. Transcriptome analysis identified 2736 differentially expressed genes between MCC and SCCIS. Genes upregulated in the MCC component included Polycomb repressive complex targets; downregulated transcripts included epidermal markers, and immune genes such as HLA-A. Immunohistochemical studies revealed increased expression of SOX2 in the MCC component, with diminished H3K27Me3, Rb, and HLA-A expression. In summary, MCC-SCCIS pairs demonstrate clonal relatedness. The shift to neuroendocrine phenotype is associated with loss of Rb protein expression, decrease in global H3K27Me3, and increased expression of Merkel cell genes such as SOX2. Our findings suggest an epidermal origin of MCC in this setting, and to our knowledge provide the first molecular evidence that intraepithelial squamous dysplasia may represent a direct precursor for small cell carcinoma.

Aging accelerates while multiparity delays tumorigenesis in mouse models of high-grade serous carcinoma.

OBJECTIVES: The "incessant ovulation" hypothesis links increased risk for tubo-ovarian high-grade serous carcinoma (HGSC) due to more ovulations and reduced risk conferred by pre-menopausal exposures like oral contraceptive use, multiparity, and breastfeeding. However, most women diagnosed with HGSC are postmenopausal, implying age is a major risk factor for HGSC. Our mouse model for HGSC, based on tamoxifen (TAM)-induced somatic inactivation of the Brca1, Trp53, Rb1, and Nf1 (BPRN) tumor suppressor genes in oviductal epithelium, recapitulates key genetic, histopathologic, and biological features of human HGSCs. We aimed to credential the model for future efforts to define biological and risk modification factors in HGSC pathogenesis. METHODS: BPRN mice were treated with TAM to induce tumors at defined ages and parity status. RESULTS: BPRN mice aged 9-months prior to tumor induction had markedly shorter survival than 6-8 week old mice induced to form tumors (median 46.5 weeks versus 61.5 weeks, log-rank test P = 0.0006). No significant differences in cancer phenotypes were observed between multiparous versus nulliparous BPRN mice. However, using a modified tumor model with one wild-type Nf1 allele (BPRNfl/+), nulliparous mice had more advanced tumors than multiparous mice (Mantel-Haenszel Chi-square test of association, P = 0.01). CONCLUSIONS: Our findings show aging is associated with significantly shortened survival post tumor induction in the BRPN model and multiparity delays development and/or progression of HGSC in certain genetic contexts. The findings support relevance of our mouse model to gain mechanistic insights into how known factors exert their protective effects and to test novel approaches for HGSC prevention.

Uterine PEComatosis With TSC1 Mutation in a Patient With Tuberous Sclerosis: Case Report and Literature Review.

Uterine PEComatosis is a rare phenomenon characterized by the presence of multiple perivascular epithelioid cell tumors (PEComas) and/or microscopic proliferations of perivascular epithelioid cells. Herein, we report a case of PEComatosis arising in a 49-yr-old woman with a known history of tuberous sclerosis. Targeted next-generation sequencing revealed a TSC1 stopgain mutation (p.Q732X) in all tested nodules, with single-copy TSC1 loss or copy-neutral TSC1 loss of heterozygosity. To our knowledge, this is the second report of TSC1 inactivation in uterine PEComa and the first report of confirmed TSC1 abnormalities in PEComatosis.

Extent of Extranodal Extension in Oral Cavity Squamous Cell Carcinoma is Not Independently Associated With Overall or Disease-Free Survival at a 2.0-mm Threshold.

PURPOSE: The presence of extranodal extension (ENE) conveys a poor prognosis in oral cavity squamous cell carcinoma (OSCC); however, there is no consensus regarding whether the histopathologic extent of ENE (e-ENE) may be a more discriminating prognostic indicator. The purpose of this study was to assess the impact of minor ENE (<2.0 mm) versus major ENE (≥ 2.0 mm) on overall survival (OS) and disease-free survival (DFS) in OSCC. MATERIALS AND METHODS: A single-institution, retrospective cohort study was designed using an electronic medical record review. Inclusion criteria included patients with OSCC and cervical node metastasis. All subjects were treated between the years 2009 and 2017 in the Michigan Medicine Department of Oral and Maxillofacial Surgery (Ann Arbor, Michigan). The primary predictor variable was e-ENE, measured as the maximum distance of tumor invasion into extranodal tissue from the outer aspect of the nodal capsule. Primary outcome variables were OS and DFS. Other covariates included demographic data, tumor staging, and histopathologic data. Descriptive statistics were performed. Kaplan-Meier survival plots for OS and DFS were performed. The data were mined for an alternative threshold at which e-ENE may impact survival using Cox proportional hazards models. RESULTS: One hundred sixty eight subjects were included (91 ENE-negative, 48 minor ENE, and 29 major ENE). Most subjects were male (62%) and the mean age was 62.9 years. Mean follow-up time was 2.97 +/- 2.76 years. There was no statistically significant difference in OS or DFS between minor and major ENE. Five-year OS for minor ENE was 30.4% versus 20.7% for major ENE (P = .28). Five-year DFS for minor ENE was 26.7% versus 18.1% for major ENE (P = .30). Five-year OS and DFS was worse for subjects with ENE-positive disease versus ENE-negative disease (OS: 26.9% vs 63.1%, hazard ratio [HR]: 2.70, 95% confidence interval [CI]: [1.77, 4.10], P < .001; DFS: 23.7% vs 59.7%, HR = 2.55, 95% CI [1.71, 3.79], P < .001). At an alternative threshold of 0.9 mm e-ENE, there was greater DFS in subjects with e-ENE 0.1-0.9 mm versus e-ENE > 0.9 (40.6% vs 18.9%, respectively) (HR = 0.49, 95% CI [0.24, 0.99], P = .047). CONCLUSION: There was no independent association between survival and e-ENE at a 2.0-mm threshold.

TP53 mutations and CDKN2A mutations/deletions are highly recurrent molecular alterations in the malignant progression of sinonasal papillomas.

Sinonasal papillomas are benign epithelial tumors of the sinonasal tract that are associated with a synchronous or metachronous sinonasal carcinoma in a subset of cases. Our group recently identified mutually exclusive EGFR mutations and human papillomavirus (HPV) infection in inverted sinonasal papillomas and frequent KRAS mutations in oncocytic sinonasal papillomas. We also demonstrated concordant mutational and HPV infection status in sinonasal papilloma-associated sinonasal carcinomas, confirming a clonal relationship between these tumors. Despite our emerging understanding of the oncogenic mechanisms driving formation of sinonasal papillomas, little is currently known about the molecular mechanisms of malignant progression to sinonasal carcinoma. In the present study, we utilized targeted next-generation DNA sequencing to characterize the molecular landscape of a large cohort of sinonasal papilloma-associated sinonasal carcinomas. As expected, EGFR or KRAS mutations were present in the vast majority of tumors. In addition, highly recurrent TP53 mutations, CDKN2A mutations, and/or CDKN2A copy-number losses were detected; overall, nearly all tumors (n = 28/29; 96.6%) harbored at least one TP53 or CDKN2A alteration. TERT copy-number gains also occurred frequently (27.6%); however, no TERT promoter mutations were identified. Other recurrent molecular alterations included NFE2L2 and PIK3CA mutations and SOX2, CCND1, MYC, FGFR1, and EGFR copy-number gains. Importantly, TP53 mutations and CDKN2A alterations were not detected in matched sinonasal papillomas, suggesting that these molecular events are associated with malignant transformation. Compared to aerodigestive tract squamous cell carcinomas from The Cancer Genome Atlas (TCGA) project, sinonasal papilloma-associated sinonasal carcinomas have a distinct molecular phenotype, including more frequent EGFR, KRAS, and CDKN2A mutations, TERT copy-number gains, and low-risk human papillomavirus (HPV) infection. These findings shed light on the molecular mechanisms of malignant progression of sinonasal papillomas and may have important diagnostic and therapeutic implications for patients with advanced sinonasal cancer.

Chromophobe Renal Cell Carcinoma with Radiologic-Pathologic Correlation.

Renal cell carcinoma (RCC) is a heterogeneous group of neoplasms derived from the renal tubular epithelial cells. Chromophobe RCC (chRCC) is the third most common subtype of RCC, accounting for 5% of cases. chRCC may be detected as an incidental finding or less commonly may manifest with clinical symptoms. The mainstay of therapy for chRCC is surgical resection. chRCC has a better prognosis compared with the more common clear cell RCC. At gross pathologic analysis, chRCC is a solid well-defined mass with lobulated borders. Histologic findings vary by subtype but include large pale polygonal cells with abundant transparent cytoplasm, crinkled "raisinoid" nuclei with perinuclear halos, and prominent cell membranes. Pathologic analysis reveals only moderate vascularity. The most common imaging pattern is a predominantly solid renal mass with circumscribed margins and enhancement less than that of the renal cortex. The authors discuss chRCC with emphasis on correlative pathologic findings and illustrate the multimodality imaging appearances of chRCC by using cases from the Radiologic Pathology Archives of the American Institute for Radiologic Pathology. ©RSNA, 2021.

Comparison of Early Oral Cancer Depth of Invasion From the American Joint Committe on Cancer 7th to 8th Edition Criteria. Does the Difference Impact the Accuracy of Clinical Decision Making?

PURPOSE: Depth of invasion (DOI) is an independent predictor of regional metastasis in oral squamous cell carcinoma. Measurement criteria for DOI were modified in the American Joint Committee on Cancer (AJCC) eighth edition. The purpose of this study was to compare DOI AJCC seventh (DOI7) and eighth (DOI8) edition criteria on frozen section accuracy for decisions regarding elective neck dissection (END) in cT1N0 oral squamous cell carcinoma. PATIENTS AND METHODS: A blinded, retrospective, comparative study of patients who underwent ablative surgery at the University of Michigan was completed. The predictor variable was criteria for DOI measurement. The outcome variables were concordance between DOI7 and DOI8 measurements and accuracy using thresholds for END. Effect of tumor growth pattern and worst pattern of invasion, and the difference between DOI8 on frozen and permanent specimen were assessed. RESULTS: A total of 30 specimens of T1N0 oral squamous cell carcinoma (16 tongue, 5 alveolus, 5 floor of mouth, 4 buccal mucosa) were included. DOI7 versus DOI8 on frozen and permanent specimen were significantly different (P < .05) but clinically insignificant and highly correlated (r > 0.99, P < .001). One hundred percent concordance between DOI7 and DOI8 was noted on frozen specimen in predicting the need for END when compared with permanent pathology DOI. There was no significant impact of tumor growth pattern or worst pattern of invasion on measurements and no significant difference in DOI on frozen and permanent specimen for DOI8 (P = .68). Excellent agreement between pathologists for all measurements was observed (ICC>0.99, P < 0001). CONCLUSIONS: High concordance between DOI measurements by AJCC seventh and eighth edition criteria suggests that guidelines for DOI thresholds for END in patients with T1N0 tumors developed using the AJCC seventh edition can be safely applied using AJCC eighth edition criteria. DOI measurement by AJCC 8 criteria on frozen specimen can be used to guide decision-making regarding END, given the high correlation to AJCC 8 permanent DOI measurement.

Molecular characterization of uterine and ovarian tumors with mixed epithelial and germ cell features confirms frequent somatic derivation.

Ovarian germ cell tumors, including yolk sac tumors, are most commonly diagnosed in children and young women. Most so-called yolk sac tumors reported in women >35 years old have been associated with an epithelial proliferation (endometriosis or carcinoma). Here, we describe eight cases clinically diagnosed as uterine or ovarian germ cell tumors in women >35 years old. In addition to routine morphologic examination and immunohistochemical evaluation, we present data from targeted next-generation sequencing (NGS) and isochromosome (12p) fluorescence in situ hybridization (FISH). We identified two groups of tumors with mixed germ cell and epithelial features: (1) tumors with background endometriosis and endometrioid carcinoma-like mutations (PTEN, PIK3CA, FGFR2, and CTNNB1), and (2) high-grade morphology, presumptive presence of isochromosome (12p) by FISH, and TP53 or PIK3CA mutations. These findings support the notion that the "germ cell tumor" component of these tumors is often somatically derived. Two tumors in our cohort were from premenopausal women; one showed no detectable mutations by NGS (suggestive of germ cell derivation), whereas the other showed PIK3CA, PTEN, and CTNNB1 mutations (suggestive of somatic derivation). Accurate classification of these tumors is likely important for selection of appropriate chemotherapy.

Next-generation sequencing implicates oncogenic roles for p53 and JAK/STAT signaling in microcystic adnexal carcinomas.

Microcystic adnexal carcinoma is a locally aggressive sweat gland carcinoma characterized by its infiltrative growth and histopathologic overlap with benign adnexal tumors, often posing challenges to both diagnosis and management. Understanding the molecular underpinnings of microcystic adnexal carcinoma may allow for more accurate diagnosis and identify potential targetable oncogenic drivers. We characterized 18 microcystic adnexal carcinomas by targeted, multiplexed PCR-based DNA next-generation sequencing of the coding sequence of over 400 cancer-relevant genes. The majority of cases had relatively few (<8) prioritized somatic mutations, and lacked an ultraviolet (UV) signature. The most recurrent mutation was TP53 inactivation in four (22%) tumors. Frame-preserving insertions affecting the kinase domain of JAK1 were detected in three (17%) cases, and were nonoverlapping with TP53 mutations. Seven (39%) cases demonstrated copy number gain of at least one oncogene. By immunohistochemistry, p53 expression was significantly higher in microcystic adnexal carcinomas with TP53 mutations compared with those without such mutations and syringomas. Similarly, phospho-STAT3 expression was significantly higher in microcystic adnexal carcinomas harboring JAK1 kinase insertions compared with those with wild-type JAK1 and syringomas. In conclusion, microcystic adnexal carcinomas are molecularly heterogeneous tumors, with inactivated p53 or activated JAK/STAT signaling in a subset. Unlike most other nonmelanoma skin cancers involving sun-exposed areas, most microcystic adnexal carcinomas lack evidence of UV damage, and hence likely originate from a relatively photo-protected progenitor population in the dermis. These findings have implications for the biology, diagnosis, and treatment of microcystic adnexal carcinomas, including potential for therapeutic targeting of p53 or the JAK/STAT pathway in advanced tumors.

Genital verruciform xanthoma: lessons from a contemporary multi-institutional series.

AIMS: Verruciform xanthoma (VX) is an uncommon lesion, seen in the oral mucosa and rarely occurring at cutaneous genital sites. Reports of exceptional VX presentations dominate the literature; herein, we assess the clinical and histological features of a cohort of routine, consecutive cases. METHODS AND RESULTS: Clinicopathological features of genital VXs from four academic centres were reviewed. A cohort of 25 lesions from 24 patients (22 male, two female; median age = 62 years), occurred on the scrotum (84%), penis (8%) and perineum/vulva (8%). VX was never suspected clinically; considerations ranged from fibroepithelial polyps to squamous cell carcinoma. Classic diagnostic criteria were present at least focally in each lesion, including verrucous architecture, prominent wedge-shaped parakeratosis extending between exophytic epidermal projections and neutrophils in the stratum corneum. Xanthomatous cells were present in all cases, but scattered to rare in 24%. CONCLUSIONS: Consecutive genital VXs reliably exhibited classic histopathological features, although the essential finding of xanthomatous cells may be scarce. Our comparison to meta-analyses of published cases found relatively fewer penile and vulvar examples. Additionally, the median age was older than in published series, which have emphasised syndromic associations.

Clinicopathological characterisation of renal cell carcinoma in young adults: a contemporary update and review of literature.

AIMS: Renal cell carcinomas are relatively rare in children and young adults. While well characterised in adults, the morphological and molecular characterisation of these tumours in young patients is relatively lacking. The objective of this study was to explore the spectrum of renal cell carcinoma (RCC) subtypes in children and young adults and to determine their clinico-pathological, immunohistochemical and molecular characteristics by evaluating a large retrospective cohort of renal cell carcinoma patients age 30 years or younger. METHODS AND RESULTS: Sixty-eight cases with confirmed diagnosis of renal cell carcinoma at age 30 years or younger were identified at our institution. Clear cell carcinoma accounted for the most common subtype seen in this age group. Translocation renal cell carcinoma and rare familial syndrome subtypes such as succinate dehydrogenase deficient renal cell carcinoma and tuberous sclerosis complex-associated renal cell carcinoma were found relatively more frequently in this cohort. Despite applying the 2016 WHO classification criteria, a high proportion of the tumours in our series remained unclassified. CONCLUSIONS: Our results suggest that renal cell carcinoma in children and young adults is a relatively rare disease that shares many histological similarities to renal cell carcinoma occurring in adults and yet demonstrate some unique clinical-pathological differences. Microphthalmia-associated transcription (MiT) family translocation RCC and rare familial syndrome subtypes are relatively more frequent in the paediatric and adolescent age groups than in adults. Clear cell RCC still accounted for the most common subtype seen in this age group. MiT family translocation RCC patients presented with advanced stage disease and had poor clinical outcomes. The large and heterogeneous subgroup of unclassified renal cell carcinoma contains phenotypically distinct tumours with further potential for future subcategories in the renal cell carcinoma classification.

Photoacoustic spectral analysis at ultraviolet wavelengths for characterizing the Gleason grades of prostate cancer.

The diagnosis of aggressive prostate cancer (PCa) has relied on microscopic architectures, namely Gleason patterns, of tissues extracted through core biopsies. Technology capable of assessing the tissue architecture without tissue extraction will reduce the invasiveness of PCa diagnosis and improve diagnostic accuracy by allowing for more sampling locations. Our recently developed photoacoustic spectral analysis (PASA) has achieved quantification of tissue architectural heterogeneity interstitially. Taking advantage of the unique optical absorption of cell nuclei at ultraviolet (UV) wavelengths, this study investigated PASA at 266 nm for quantifying the tissue architecture heterogeneity in prostates. The results have shown significant differences among the normal, early cancer, and late cancer stages in mouse prostates ex vivo and in vivo (n=20, p<0.05). The study with human samples ex vivo has shown a correlation of 0.80 (n=11, p<0.05) between PASA quantification and pathologic diagnosis.

Targeted RNAseq of Formalin-Fixed Paraffin-Embedded Tissue to Differentiate Among Benign and Malignant Adrenal Cortical Tumors.

Lack of routine fresh or frozen tissue is a barrier to widespread transcriptomic analysis of adrenal cortical tumors and an impediment to translational research in endocrinology and endocrine oncology. Our group has previously pioneered the use of targeted amplicon-based next-generation sequencing for archival formalin-fixed paraffin-embedded (FFPE) adrenal tissue specimens to characterize the spectrum of somatic mutations in various forms of primary aldosteronism. Herein, we developed and validated a novel 194-amplicon targeted next-generation RNA sequencing (RNAseq) assay for transcriptomic analysis of adrenal tumors using clinical-grade FFPE specimens. Targeted RNAseq-derived expression values for 27 adrenal cortical tumors, including aldosterone-producing adenomas (APA; n=8), cortisol-producing adenomas (CPA; n=11), and adrenal cortical carcinomas (ACC; n=8), highlighted known differentially-expressed genes (DEGs; i. e., CYP11B2, IGF2, etc.) and tumor type-specific transcriptional modules (i. e., high cell cycle/proliferation transcript expression in ACC, etc.), and a subset of DEGs was validated orthogonally using quantitative reverse transcription PCR (qRT-PCR). Finally, unsupervised hierarchical clustering using a subset of high-confidence DEGs revealed three discrete clusters representing APA, CPA, and ACC tumors with corresponding unique gene expression signatures, suggesting potential clinical utility for a transcriptomic-based approach to tumor classification. Overall, these data support the use of targeted amplicon-based RNAseq for comprehensive transcriptomic profiling of archival FFPE adrenal tumor material and indicate that this approach may facilitate important translational research opportunities for the study of these tumors.

Cervical Mesonephric Adenocarcinoma With Novel FGFR2 Mutation.

Mesonephric adenocarcinoma is a rare tumor, accounting for <1% of cervical cancers. Well-differentiated mesonephric adenocarcinoma can be difficult to distinguish from diffuse mesonephric hyperplasia. Herein, we report a case of well-differentiated mesonephric adenocarcinoma with an FGFR2 mutation not previously reported in the literature. Nonselective tyrosine kinase inhibitors or FGFR2 inhibitors may represent options for targeted therapy.