Solid-Basaloid Adenoid Cystic Carcinoma of the Breast: An Aggressive Subtype Enriched for Notch Pathway and Chromatin Modifier Mutations With MYB Overexpression.

Adenoid cystic carcinoma (AdCC) is a rare triple-negative breast cancer analogous to its extramammary counterparts. Diagnosis of the more aggressive solid-basaloid variant of AdCC (SB-AdCC) can be challenging due to poorly defined histopathologic and molecular features. We characterized 22 invasive and in situ basaloid carcinomas by morphology, immunohistochemistry, genetics, and MYB status using multiple platforms and assessed clinical behavior and neoadjuvant chemotherapy responses. After consensus review, 16/22 cases were classified as SB-AdCC. All SB-AdCC had predominantly solid growth and at least focal myxohyaline stroma and were immune-poor. Eosinophilic squamoid cells (69%, 11/16) and basement membrane-like secretions (69%, 11/16) were common, and intercalated ducts (31%, 5/16) were less frequent. SB-AdCC typically expressed SOX10 (100%, 16/16) and luminal markers (100%, 16/16 CK7; 88%, 14/16 CD117; 93%, 13/14 CAM5.2). SMA (40%, 6/15) expression was less common, and SMM (27%, 3/11), GATA3 (20%, 3/15), and p63 (25%, 4/16) were mostly negative. MYB protein and/or MYB RNA overexpression was universal in evaluable cases (13/13), with RNA in situ hybridization (10/10) more reliable than immunohistochemistry (10/11, plus 4 excisions inconclusive). Fluorescence in situ hybridization and/or next-generation sequencing identified MYB rearrangements (20%, 3/15) and amplifications/copy gains (60%, 9/15) but no MYB::NFIB fusions. SB-AdCC often had aberrations in Notch pathway (60%, including 40% NOTCH1 and 20% NOTCH2) and/or chromatin modifier (60%, including 33% CREBBP) genes, with relatively infrequent TP53 mutations (27%). Unclassified invasive basaloid carcinomas lacking described histologic features of SB-AdCC (n = 4) and basaloid ductal carcinoma in situ (n = 2) showed similar immunoprofiles and genetics as SB-AdCC, including Notch aberrations and MYB overexpression with MYB rearrangements/amplifications. Overall, nodal (22%) and distant (33%) metastases were common, and 23% of patients died of disease (mean follow-up, 35 months; n = 22). Responses were poor in all 7 neoadjuvant chemotherapy-treated patients, without any achieving pathologic complete response. The data highlight the histopathologic spectrum of basaloid carcinomas including SB-AdCC and reveal shared genetics and MYB activation, which can be diagnostically useful. Aggressive behavior and poor treatment responses emphasize a need for additional treatment approaches.

Genetic and Immunohistochemical Profiling of Mammary Hidradenoma and Comparison to Mucoepidermoid Carcinoma.

Mucoepidermoid carcinoma (MEC) is exceedingly rare in the breast, with <45 cases reported in the literature. Although estrogen receptor/progesterone receptor/human epidermal growth factor 2 triple-negative, MEC is characterized as a special subtype of breast carcinoma with significantly better prognosis than conventional basal-type tumors. Cutaneous hidradenoma (HA) is considered a benign adnexal neoplasm showing histomorphologic overlap with MEC. Rare cases of HA have also been reported in the breast, but these are relatively uncharacterized. In this study, we examined the clinicopathologic, immunohistochemical (IHC), and genetic features of 8 breast HAs, in comparison to 3 mammary MECs. All cases were positive for MAML2 break-apart fluorescence in situ hybridization. Eight cases demonstrated a CRTC1::MAML2 fusion, and one MEC harbored a CRTC3::MAML2 fusion; the latter is a novel finding in the breast. Mutational burden was very low, with only one HA exhibiting a MAP3K1 pathogenic alteration. By IHC, both MEC and HA demonstrated cell type-dependent expression of high- and low-molecular-weight keratins and p63, as well as negative to low-positive estrogen receptor and androgen receptor. Smooth muscle myosin and calponin highlighted an in situ component in the 3 cases of MEC; expression of these myoepithelial markers was negative in HAs. Additional distinguishing characteristics included the growth pattern and tumor architecture, the presence of glandular/luminal cells in HA, and overall higher IHC expression of SOX10, S100 protein, MUC4, and mammaglobin in MEC. Morphologic findings were also compared to a series of 27 cutaneous nonmammary HAs. Mucinous and glandular/luminal cells were identified in significantly more mammary HAs than nonmammary lesions. The findings provide insight into the pathogenesis of MAML2-rearranged neoplasms of the breast, underscore the overlapping genetic features of MEC and HA, and highlight similarities to their extramammary counterparts.

Gag p24 Is a Marker of Human Immunodeficiency Virus Expression in Tissues and Correlates With Immune Response.

We demonstrate that human immunodeficiency virus (HIV) gag p24 protein is more readily detected in gut and lymph node tissues than in blood CD4+ T cells and correlates better with CD4 count during antiretroviral therapy (ART). Gut p24 levels also measurably decline with ART in natural controllers. During ART, gut p24 expression is more strongly associated both with HIV-specific CD8+ T-cell frequency and plasma soluble CD14 levels than gut HIV RNA expression. This study supports using gag p24 as a marker of HIV expression in HIV+ tissues to study effects of viral persistence and to monitor efficacy of treatment in HIV-based clearance studies.

Gastric-type endocervical adenocarcinoma and cervical cytology: Experience at a general hospital and review of the literature.

INTRODUCTION: Gastric-type endocervical adenocarcinoma (GAS) is an uncommon type of endocervical adenocarcinoma that is not associated with human papillomavirus infection. This diagnosis is relatively rare and may portend a worse prognosis than usual-type endocervical adenocarcinoma. Subtle morphological features make it an under-recognised diagnostic challenge. Study of the cytological features of individual cases is valuable in order to increase awareness of this entity. METHODS: The pathology database of our institution was searched for the diagnosis of GAS and all cytological and surgical specimens for each patient were reviewed. The original cytological interpretation was compared to a retrospective central review interpretation. Clinical history and follow-up results were obtained from the electronic medical record. RESULTS: Four cases of GAS were identified. The findings on initial cervical cytology varied, with GAS found in both patients with negative cervical cytology and those with atypical glandular cells. Cytological findings included endocervical cells arranged in three-dimensional clusters and honeycomb sheets with abundant vacuolar cytoplasm, and in two patients, moderate nuclear atypia with irregular nuclear membranes, coarse chromatin, hyperchromatic nuclei, and prominent nucleoli. In one patient, GAS was incidentally discovered via thorough sampling of a cystic lesion in the superior portion of the endocervical canal. CONCLUSIONS: GAS is an aggressive human papillomavirus-independent type of endocervical adenocarcinoma with subtle morphological features and, as our study shows, varying clinical presentation. Given the aggressive nature of GAS and the difficulties in initial diagnosis, increased awareness of this entity among pathologists is crucial.

Primary mammary angiosarcomas harbor frequent mutations in KDR and PIK3CA and show evidence of distinct pathogenesis.

Angiosarcoma (AS) is the most frequent primary sarcoma of the breast but nevertheless remains uncommon, accounting for <0.05% of breast malignancies. Secondary mammary AS arise following radiation therapy for breast cancer, in contrast to primary AS which occur sporadically. Essentially all show aggressive clinical behavior independent of histologic grade and most are treated by mastectomy. MYC amplification is frequently identified in radiation-induced AS but only rarely in primary mammary AS (PMAS). As a heterogeneous group, AS from various anatomic sites have been shown to harbor recurrent alterations in TP53, MAP kinase pathway genes, and genes involved in angiogenic signaling including KDR (VEGFR2) and PTPRB. In part due to its rarity, the pathogenesis of PMAS has not been fully characterized. In this study, we examined the clinical, pathologic, and genomic features of ten cases of PMAS, including one patient with bilateral disease. Recurrent genomic alterations were identified in KDR (70%), PIK3CA/PIK3R1 (70%), and PTPRB (30%), each at higher frequencies than reported in AS across all sites. Six tumors harbored a KDR p.T771R hotspot mutation, and all seven KDR-mutant cases showed evidence suggestive of biallelism (four with loss of heterozygosity and three with two aberrations). Of the seven tumors with PI3K alterations, six harbored pathogenic mutations other than in the canonical PIK3CA residues which are most frequent in breast cancer. Three AS were hypermutated (≥10 mutations/megabase (Mb)); hypermutation was seen concurrent with KDR or PIK3CA mutations. The patient with bilateral disease demonstrated shared alterations, indicative of contralateral metastasis. No MYC or TP53 aberrations were detected in this series. Immunohistochemistry for VEGFR2 was unable to discriminate between KDR-mutant tumors and benign vascular lesions of the breast. These findings highlight the underrecognized frequency of KDR and PIK3CA mutation in PMAS, and a significant subset with hypermutation, suggesting a pathogenesis distinct from other AS.

Fine-Needle Aspiration Biopsy of Liver Lesions Yields Higher Tumor Fraction for Molecular Studies: A Direct Comparison With Concurrent Core Needle Biopsy.

BACKGROUND: This retrospective study evaluated and compared the diagnostic accuracy and suitability of tissue specimens for advanced molecular diagnostic testing obtained via 2 different techniques for percutaneous biopsy of primary and metastatic liver tumors. PATIENTS AND METHODS: Samples from 137 patients with liver masses who underwent concurrent fine-needle aspiration biopsy with cell block (FNAB-CB) and core needle biopsy (CNB) at 2 hospitals were assessed for diagnostic accuracy, tumor fraction, and tumor cellularity. A subset of FNAB-CBs, that were deemed to have less or equal tumor cellularity compared with CNBs, had level sections performed and were reassessed for tumor cellularity. RESULTS: Diagnostic accuracy was 96% for FNAB and 93% for CNB (P=.267). In FNAB-CBs, tumor fraction was significantly higher than in CNB samples (67% vs 36%; P<.0001), whereas nontumor components were significantly lower (stromal component, 7% vs 29%; P<.0001; background benign hepatocytes, 25% vs 36%; P=.003). Additionally, in 44% of cases, FNAB-CB tumor cellularity was equal to or greater than that of the concurrent CNB. CONCLUSIONS: In the current age of personalized medicine, a minimally invasive, safe approach to obtaining adequate tissue for myriad molecular testing is paramount. We have shown that FNAB sampling is diagnostically accurate and produces higher tumor fractions than CNB. Thus, FNAB should be strongly considered as an initial sampling modality, especially for patients in whom molecular tests will determine management.

Genomic profiling of malignant phyllodes tumors reveals aberrations in FGFR1 and PI-3 kinase/RAS signaling pathways and provides insights into intratumoral heterogeneity.

Malignant phyllodes tumors of the breast are poorly understood rare neoplasms with potential for aggressive behavior. Few efficacious treatment options exist for progressed or metastatic disease. The molecular features of malignant phyllodes tumors are poorly defined, and a deeper understanding of the genetics of these tumors may shed light on pathogenesis and progression and potentially identify novel treatment approaches. We sequenced 510 cancer-related genes in 10 malignant phyllodes tumors, including 5 tumors with liposarcomatous differentiation and 1 with myxoid chondrosarcoma-like differentiation. Intratumoral heterogeneity was assessed by sequencing two separate areas in 7 tumors, including non-heterologous and heterologous components of tumors with heterologous differentiation. Activating hotspot mutations in FGFR1 were identified in 2 tumors. Additional recurrently mutated genes included TERT promoter (6/10), TP53 (4/10), PIK3CA (3/10), MED12 (3/10), SETD2 (2/10) and KMT2D (2/10). Together, genomic aberrations in FGFR/EGFR PI-3 kinase and RAS pathways were identified in 8 (80%) tumors and included mutually exclusive and potentially actionable activating FGFR1, PIK3CA and BRAF V600E mutations, inactivating TSC2 mutation, EGFR amplification and PTEN loss. Seven (70%) malignant phyllodes tumors harbored TERT aberrations (six promoter mutations, one amplification). For comparison, TERT promoter mutations were identified by Sanger sequencing in 33% borderline (n=12) and no (0%, n=8) benign phyllodes tumors (P=0.391 and P=0.013 vs malignant tumors, respectively). Genetic features specific to liposarcoma, including CDK4/MDM2 amplification, were not identified. Copy number analysis revealed intratumoral heterogeneity and evidence for divergent tumor evolution in malignant phyllodes tumors with and without heterologous differentiation. Tumors with liposarcomatous differentiation revealed more chromosomal aberrations in non-heterologous components compared with liposarcomatous components. EGFR amplification was heterogeneous and present only in the non-heterologous component of one tumor with liposarcomatous differentiation. The results identify novel pathways involved in the pathogenesis of malignant phyllodes tumors, which significantly increase our understanding of tumor biology and have potential clinical impact.

Fine needle aspiration biopsy in low- and middle-income countries.

Fine needle aspiration biopsy (FNAB) in low- and middle-income countries (LMIC), can provide minimally invasive, cost-effective tissue diagnosis with rapid assessment and specimen triage, which is advantageous in these resource-limited settings. Nevertheless, challenges such as equipment shortages, reagents, and lack of trained personnel exist. This article discusses the effectiveness of FNAB for diagnosis of malignant and inflammatory conditions across various organs, such as lymph nodes, breast, soft tissue, and thyroid and advocates for increased training opportunities and collaboration with academic centers to enhance diagnostic accuracy and access to pathology services.

Cytopathology in the era of social media.

In today's medical landscape, social media (SoMe) platforms have expanded their reach beyond mere communication and entertainment, making a significant impact in the pathology field, including cytopathology. In recent years, SoMe platforms have become increasingly adopted by cytopathologists, facilitating continued education, professional networking, enhancing patient engagement, and entertainment. This adoption has influenced the professional growth of cytopathologists, and at its best, has led to the establishment of a robust professional online presence and ultimately contributed to leadership positions, fellowship opportunities, and academic promotions. Moreover, the integration of SoMe into the academic field has shown a profound impact on the visibility of academic journals and has provided a platform for lower-impact factor journals to expand their reach, ultimately increasing article citation rates and positively contributing to journal impact factor growth. SoMe platforms created a modern avenue for conference networking that has revolutionized knowledge dissemination and enhanced real-time engagement. The advantages of SoMe have extended to a global scale, positively enhancing professional expertise sharing, facilitating effective communication and teleconsultation worldwide, and reaching developing countries. Drawing insights from the recent medical literature and the practical insight from the experts' personal experience, this article provides a comprehensive review of how SoMe and cytopathology intersect to create new opportunities, facilitating informed discussions, global collaboration, and advancements in the field of cytopathology. This article also delves into the challenges surrounding SoMe platform navigation and addresses ethical and regulatory concerns, providing guidelines on what to post and what not to post on SoMe platforms.

A comprehensive review of anal cancer-with a special focus on anal cytology.

The diagnosis of anal cancer is relatively uncommon, but its incidence has been steadily increasing in high-risk populations. In the 2001 Bethesda System for Reporting Cervical Cytology, anal cytology was introduced as a component. Since then, it has been recognized as a potential tool for screening anal cancer, often in conjunction with high-resolution anoscopy. There are notable similarities between anal cancer and cervical cancer, including the causative role of human papillomavirus. However, there are also significant differences, particularly in terms of disease prevalence. Anal cytology may be used as a primary screening test, and in the event of abnormalities, patients are subsequently directed for high-resolution anoscopy. However, the best approach for anal cancer screening is yet to be determined and uniformly implemented. This comprehensive review article provides an in-depth analysis of the epidemiology and incidence of anal precursor and malignant lesions. It explores the various methods of sample procurement, preparation, interpretation (including sensitivity and specificity), and reporting terminology in anal cytology. The article also addresses the significance of concurrent high-risk human papillomavirus screening in anal cytology and its role in screening programs. Furthermore, it discusses the follow-up, prevention, and subsequent management strategies for anal cancers. By synthesizing current knowledge in these areas, this review aims to provide a comprehensive understanding of anal cytology and its implications in the early detection, prevention, and management of anal neoplasia and cancer.

Evaluation of URO17® to improve non-invasive detection of bladder cancer.

BACKGROUND: The gold standard for detecting bladder cancer is cystoscopy with biopsy or transurethral resection confirming histologic diagnosis. URO17® employs a chromogenically labeled monoclonal antibody to keratin 17 (k17), an intermediate filament cytoskeleton molecule associated with bladder, pancreatic, and cervical cancers. Preliminary studies evaluating k17 demonstrated a high sensitivity and specificity for the detection of bladder cancer, supporting the need for further study. OBJECTIVE: To evaluate the sensitivity and specificity of URO17. METHODS: This is a cross-sectional study of participants undergoing urologic procedures between July 6, 2018 and July 17, 2019 at a single institution. Patients undergoing cystectomy, endoscopic bladder and/or upper tract procedure for probable urothelial carcinoma comprised cases; patients undergoing urologic procedures for other reasons comprised the control group (i.e. prostatectomy, nephrectomy, etc.). Voided urine samples were at the time of procedure; a minority of participants underwent multiple resections in the study period, thus, as many as three urine samples were taken from any given participant. Samples were distributed for blinded testing with URO17. Sensitivity and specificity were calculated. RESULTS: In 152 participants and 167 samples, URO17 demonstrated an overall sensitivity of 90% and 92% and a specificity of 88% and 87%, respectively. In 76 participants and 91 samples from patients with suspected urothelial carcinoma, the sensitivity was 90% and 92%, and the specificity was 50% and 54%, respectively. No controls demonstrated a positive URO17 result, and URO17 superseded urine cytology detection of low-grade and high-grade Ta. False positive results were associated with inflamed tissue or urothelial atypia on histology; the large majority had a history of intravesical therapy. CONCLUSION: Limitations include cross-sectional design and convenience sampling. URO17 may improve sensitivity of urine cytology in the detection of urothelial cancer, though further study is required to refine the application of this biomarker in clinical practice.

Utility and performance of cell blocks in cerebrospinal fluid cytology: Experience at two teaching hospitals.

BACKGROUND: Cytology cell blocks (CBs) are not routinely made for cerebrospinal fluid (CSF) specimens. The goal of this study was to identify when CSF CB preparation improves diagnostic performance. MATERIALS AND METHODS: Under institutional review board approval, a retrospective review of CSF cytology cases was conducted at a tertiary university-based hospital and an affiliated county hospital. Patient history, CSF volume, final diagnosis, use of stains, and whether the CB was contributory was determined from the cytopathology report. CSF nucleated cell count data was obtained from the medical record. RESULTS: A total of 69 CSF specimens with CBs from January 2006 to March 2023 were identified from 61 patients. The median CSF volume was 8 mL (interquartile range, 4-13 mL; range, 1-800 mL), with immunohistochemical stains performed on 29 (42%) cases. Per cytology report, CB was contributory in 23 cases (33%), not contributory in 34 cases (49%), and not discussed in 12 cases (17%). The median volume was 8 mL for cases in which CB was contributory, not contributory, or not discussed. There was no difference in average nucleated cell counts between cases in which CB was contributory versus not contributory (73.9 vs. 40.0, p = .175). CONCLUSIONS: CBs for CSF samples were contributory in a subset (33%) of cases. The authors were unable to identify any specific pre-analytic factors, including specimen volume and average nucleated cell counts, for cases in which CB was contributory. Further evaluation is needed to identify if there are scenarios in which CSF CBs should be routinely prepared.

Utility and performance of cell blocks in urine cytology: Experience at three teaching hospitals.

BACKGROUND: The use of cell block (CB) preparation is underused in urine cytology (UC) and varies among hospitals. In addition to confirming a diagnosis, CBs can be useful in cases of metastatic disease, diagnoses requiring immunohistochemical (IHC) staining, and for ancillary studies. The role of this study is to examine the performance of CBs for UC at three affiliated teaching hospitals. MATERIALS AND METHODS: A retrospective review of UC cases with a CB was conducted at a county hospital, Veterans Affairs hospital, and tertiary university-based hospital. For each specimen, patient demographics, specimen type, volume, original diagnosis, and IHC stains were recorded. Each case was reviewed for diagnosis based on ThinPrep alone, diagnosis based on ThinPrep and CB, utility of CB for diagnosis, and CB cellularity. RESULTS: A total of 250 UC specimens with CB from 186 patients was identified. Bladder washes were the most common (72.1%). IHC stains were performed on 17.2% of cases. On blinded review, CB preparation was deemed useful in 61.2% of cases, with the highest rate for suspicious for high-grade urothelial carcinoma (SHGUC) cases (87.0%). The diagnosis based on ThinPrep review changed with incorporation of CB in 13.2% of cases, with the highest rate for SHGUC cases (43.5%). CONCLUSIONS: The results demonstrate that use of CB in UC confirms the final diagnosis in more than one-half of cases and changes the diagnosis in a subset of cases. Use of CB was most helpful in the SHGUC category. Further evaluation of the types of cases in which CB are prepared is warranted.

Urine cytology in patients with gender confirmation surgery and hormone therapy: evaluation of urine cytology performance in an underserved patient population.

INTRODUCTION: There is a practice gap and educational need regarding urine cytology (UC) performance in patients with history of gender confirmation surgery (GCS) and/or hormone therapy (HT). This potentially impacts diagnostic accuracy in this medically underserved population. We report a methodology that identifies relevant cases and evaluates the performance of UC in this cohort. MATERIALS AND METHODS: Two institutional pathology archives from 2000 to 2021 were searched using relevant keywords to identify UC specimens from patients with GCS and/or HT for this retrospective study. For each specimen, patient demographics, relevant clinical history, and history of HT and/or GCS were noted. Each case was blindly reviewed by a cytopathologist according to The Paris System. RESULTS: A total of 32 UC specimens from 15 patients with history of GCS and/or HT were identified. There were 13 male to female and 2 female to male transgender patients. The original diagnosis was negative for high-grade urothelial carcinoma (NHGUC) in 24 of 32 (75%) and atypical urothelial cells (AUC) in 8 of 32 (25%) cases. The most common atypical features were irregular nuclear membranes and prominent small nucleoli in 7 of 8 (87.5%). Degenerative changes were present in 5 of 8 (62.5%). On re-review, with relevant clinical history, 100% of cases were re-classified as NHGUC. CONCLUSIONS: The original diagnosis of AUC in these cases likely reflects reactive changes post GCS and/or HT. This cohort may be at risk of AUC overdiagnosis, particularly if the pathologist is unaware of this clinical history. Pathologists need to recognize reactive cytomorphologic changes in these patients. Further multi-institutional studies are warranted to expand knowledge about UC performance in these patients.

Cystic Neutrophilic Granulomatous Mastitis Regression with the Tumor Necrosis Factor-α Inhibitor, Adalimumab.

Idiopathic granulomatous mastitis (IGM) is a rare, benign, inflammatory breast disease that primarily affects parous women within a period of five years post-partum. Cystic neutrophilic granulomatous mastitis (CNGM) is clinically identical to IGM, but histopathology demonstrates distinct central lipid vacuoles rimmed by neutrophils with an outer cuff of epithelioid histiocytes/granulomas, with inconsistent presence of Coryneform bacteria within the vacuoles. There is no consensus on the treatment for either IGM or CNGM, which may be managed surgically with wide local excision or mastectomy or medically with antibiotics, steroids, and steroid-sparing immunosuppressive agents. We present a 30-year-old woman with plaque psoriasis and CNGM whose breast symptoms resolved after treatment with the tumor necrosis factor alpha (TNF-α) inhibitor adalimumab, which has not previously been described as a treatment option for CNGM.

The Diagnostic Dilemma of Urothelial Tissue Fragments in Urinary Tract Cytology Specimens.

Since the release of The Paris System for Reporting Urinary Cytology (TPS), the assessment of urine cytology specimens has primarily focused on the detection of high-grade urothelial carcinoma (HGUC) and carcinoma in situ (CIS). Fortunately, the malignant cells in these lesions tend to be loosely cohesive, resulting in the natural exfoliation of individual malignant cells into the urine. However, HGUC/CIS lesions occasionally exfoliate larger fragments which can be difficult to assess due to cellular overlap and fragment three-dimensionality. Furthermore, reactive benign urothelial fragments and fragments from low-grade urothelial neoplasms (LGUN) may also be seen in urine specimens and contain atypical cytomorphologic features. As a result, the significance of urothelial tissue fragments (UTFs) is often unclear. Herein, we discuss the literature on UTFs before and after the implementation of TPS, as well as strategies to help overcome this diagnostic challenge.

Cytologic features of micropapillary variant urothelial carcinoma in urinary tract cytology: Case series and review of literature.

BACKGROUND: The micropapillary variant of urothelial carcinoma (MPVUC) is rare and aggressive. Surgical specimens often show atypical micro-clusters (AMCs) of cells with hyperchromatic, pyknotic, peripheral, irregular nuclei with variable nuclear to cytoplasmic ratios. We reviewed urinary tract cytology (UTC) from patients with MPVUC and hypothesized that AMCs would be present similar to those in surgical specimens. METHODS: The archives were searched from 2000 to 2020 for patients with surgical cases with either MPVUC or conventional high-grade urothelial carcinoma (HGUC) and with prior abnormal UTC. Two pathologists reviewed UTC cases and controls in a blinded manner for AMCs, with quantitation of none, low, moderate, and high. Interrater reliability was compared by quadratic weighted Cohen's Kappa test. The association between numerical average score and MPVUC status was determined by logistic regression. RESULTS: Five patients with invasive MPVUC, one patient with a noninvasive micropapillary component, and 15 control patients with conventional HGUC were included. All patients had prior or concurrent abnormal UTC samples. Increasing category of quantities of AMCs on cytology was associated with micropapillary status (OR 7.9, 95% CI 2.7-118, p = .045), with moderate agreement between raters (Cohen's Kappa 0.54, 95% CI 0.19-0.89, p = .004). CONCLUSIONS: In patients with MPVUC on surgical specimen, AMCs were frequently observed on cytology. Similar atypical clusters were observed in patients with nonmicropapillary HGUC, albeit at lower frequency. However, given the WHO recommendation to diagnose micropapillary only if an invasive micropapillary component is present, a specific diagnosis of MPVUC on UTC cannot be based solely on the presence of AMCs.

A Review of Effusion Cytomorphology of Small Round Cell Tumors.

BACKGROUND: Small round cell tumors (SRCTs) are a broad category of diverse malignant tumors composed of monotonous undifferentiated cells. Involvement of serous fluids by SRCT is rare; however, the identification of exfoliated malignant cells is a crucial component of management and has significant implications for treatment and prognosis. The most common effusion tumors with SRCT morphology include Ewing sarcoma, synovial sarcoma, rhabdomyosarcoma (RMS), small-cell neuroendocrine carcinoma (SCNC), and desmoplastic SRCT, and the cytomorphologic distinction between these tumors is challenging. The purpose of this article is to describe the morphologic features of the most common SRCT in fluids and propose helpful ancillary testing. SUMMARY: Effusion SRCTs display similar primitive and undifferentiated morphologic features although each has subtle variations. Ewing sarcoma is a mesenchymal neoplasm and harbors characteristic translocations t(11;22) (EWSR1-FLI1) or t(21;22) (EWSR1-ERG). In fluids, Ewing sarcoma shows poorly differentiated cells of variable size with round to oval nuclei, prominent nucleoli, and scant cytoplasm. In contrast, synovial sarcoma typically involves extremities and expresses a fusion transcript in t(X;18) (SS18-SSX). This soft tissue neoplasm demonstrates uniform cells with irregular nuclear contours, characteristic nuclear folding, and scant cytoplasm. RMS is a neoplasm arising from skeletal muscle, and the alveolar subtype demonstrates a translocation in t(2;13) (PAX3-FOXO1). The malignant cells show a spectrum of small round cells and pleomorphic large cells with rhabdoid morphology. RMS cells characteristically express myogenin and MyoD1, markers of skeletal muscle differentiation. Although SCNC is not a classic SRCT, the morphology is similar. SCNC demonstrates tight clusters of malignant cells with nuclear molding and salt-and-pepper chromatin. This tumor classically has neuroendocrine differentiation and is positive for synaptophysin and chromogranin on immunohistochemistry. And last, desmoplastic SRCT typically presents as an intra-abdominal mass in young men and characteristically harbors the translocation t(11;22) (p13;q12) (EWSR1-WT1). Cytomorphologically, the tumor shows small monomorphic cells occasionally arranged as rosette-like structures. KEY MESSAGE: The diagnosis of SRCT can be made in effusion samples and is best achieved with a combination of morphologic features, clinical history, and ancillary testing.

Deep Phenotypic Analysis of Blood and Lymphoid T and NK Cells From HIV+ Controllers and ART-Suppressed Individuals.

T and natural killer (NK) cells are effector cells with key roles in anti-HIV immunity, including in lymphoid tissues, the major site of HIV persistence. However, little is known about the features of these effector cells from people living with HIV (PLWH), particularly from those who initiated antiretroviral therapy (ART) during acute infection. Our study design was to use 42-parameter CyTOF to conduct deep phenotyping of paired blood- and lymph node (LN)-derived T and NK cells from three groups of HIV+ aviremic individuals: elite controllers (N = 5), and ART-suppressed individuals who had started therapy during chronic (N = 6) vs. acute infection (N = 8), the latter of which is associated with better outcomes. We found that acute-treated individuals are enriched for specific subsets of T and NK cells, including blood-derived CD56-CD16+ NK cells previously associated with HIV control, and LN-derived CD4+ T follicular helper cells with heightened expansion potential. An in-depth comparison of the features of the cells from blood vs. LNs of individuals from our cohort revealed that T cells from blood were more activated than those from LNs. By contrast, LNs were enriched for follicle-homing CXCR5+ CD8+ T cells, which expressed increased levels of inhibitory receptors and markers of survival and proliferation as compared to their CXCR5- counterparts. In addition, a subset of memory-like CD56brightTCF1+ NK cells was enriched in LNs relative to blood. These results together suggest unique T and NK cell features in acute-treated individuals, and highlight the importance of examining effector cells not only in blood but also the lymphoid tissue compartment, where the reservoir mostly persists, and where these cells take on distinct phenotypic features.