Intratesticular Mullerian Serous Borderline Tumor With Microinvasion: A Rare Tumor and Review of the Literature.

Ovarian-type (ie, Mullerian) epithelial tumors occurring in the testicular and paratesticular regions are exceptionally rare, with only a handful reported worldwide. Serous tumors are the most frequently encountered subtype among these rare tumors. The pathogenesis of these tumors within the testicular and paratesticular regions remains a subject of intrigue and debate, with various hypotheses attempting to explain their presence in the paratestis region, where most tumors occur. However, our understanding of the pathogenesis of intratesticular tumors is limited. To date, 11 known examples of intratesticular serous Mullerian tumors have been reported globally. In this report, we present an extraordinary tumor, an intratesticular Mullerian serous borderline tumor with foci of microinvasion, in a 38-year-old male patient. This tumor exhibits histological features similar to their ovarian counterparts and is confirmed through an immunohistochemical panel. Our report underscores the extreme rarity of these tumors, emphasizes the importance of heightened awareness among clinicians and pathologists, and provides valuable insights into their complex development and histogenesis. This contribution aims to enhance diagnostic precision and optimize therapeutic strategies for similar tumors.

Abnormal vascular structure and function within brain metastases is linked to pembrolizumab resistance.

BACKGROUND: We recently conducted a phase 2 trial (NCT028865685) evaluating intracranial efficacy of pembrolizumab for brain metastases (BM) of diverse histologies. Our study met its primary efficacy endpoint and illustrates that pembrolizumab exerts promising activity in a select group of patients with BM. Given the importance of aberrant vasculature in mediating immunosuppression, we explored the relationship between checkpoint inhibitor (ICI) efficacy and vascular architecture in the hopes of identifying potential mechanisms of intracranial ICI response or resistance for BM. METHODS: Using Vessel Architectural Imaging (VAI), a histologically validated quantitative metric for in vivo tumor vascular physiology, we analyzed dual echo DSC/DCE MRI for 44 patients on trial. Tumor and peri-tumor cerebral blood volume/flow, vessel size, arterial- and venous-dominance, and vascular permeability were measured before and after treatment with pembrolizumab. RESULTS: BM that progressed on ICI were characterized by a highly aberrant vasculature dominated by large-caliber vessels. In contrast, ICI-responsive BM possessed a more structurally balanced vasculature consisting of both small and large vessels, and there was a trend towards a decrease in under-perfused tissue, suggesting a reversal of the negative effects of hypoxia. In the peri-tumor region, development of smaller blood vessels, consistent with neo-angiogenesis, was associated with tumor growth before radiographic evidence of contrast enhancement on anatomical MRI. CONCLUSIONS: This study, one of the largest functional imaging studies for BM, suggests that vascular architecture is linked with ICI efficacy. Studies identifying modulators of vascular architecture, and effects on immune activity, are warranted and may inform future combination treatments.

Structural and functional vascular dysfunction within brain metastases is linked to pembrolizumab inefficacy.

Structurally and functionally aberrant vasculature is a hallmark of tumor angiogenesis and treatment resistance. Given the synergistic link between aberrant tumor vasculature and immunosuppression, we analyzed perfusion MRI for 44 patients with brain metastases (BM) undergoing treatment with pembrolizumab. To date, vascular-immune communication, or the relationship between immune checkpoint inhibitor (ICI) efficacy and vascular architecture, has not been well-characterized in human imaging studies. We found that ICI-responsive BM possessed a structurally balanced vascular makeup, which was linked to improved vascular efficiency and an immune-stimulatory microenvironment. In contrast, ICI-resistant BM were characterized by a lack of immune cell infiltration and a highly aberrant vasculature dominated by large-caliber vessels. Peri-tumor region analysis revealed early functional changes predictive of ICI resistance before radiographic evidence on conventional MRI. This study was one of the largest functional imaging studies for BM and establishes a foundation for functional studies that illuminate the mechanisms linking patterns of vascular architecture with immunosuppression, as targeting these aspects of cancer biology may serve as the basis for future combination treatments.

Immunophenotypic Characterization of Germ Cell Tumor-Derived Primitive Neuroectodermal Tumors: Evidence for Frequent Neuronal and/or Glial Differentiation.

CONTEXT.­: Primitive neuroectodermal tumors (PNETs) may arise as a somatic-type malignancy in germ cell tumors. In this setting, most PNETs resemble those of the central nervous system and lack chromosome 22 translocations. However, description of the morphologic and differentiation spectrum of PNETs arising from germ cell tumors is lacking. OBJECTIVE.­: To investigate the morphologic and immunohistochemical features of these tumors, concentrating on neuronal and glial features. DESIGN.­: We selected cases based on a morphologically identifiable glial and/or differentiated neuronal component in association with the undifferentiated PNET. Immunohistochemistry for glial fibrillary acidic protein, S100 protein, synaptophysin, chromogranin A, and SOX11 was performed on tumors with available material, with the scoring of both staining intensity (0-3) and extent (0-3). Thirteen qualifying PNETs of testicular origin with available immunohistochemical stains or stainable material were identified. The complete stain panel was performed in 10 tumors. RESULTS.­: SOX11 demonstrated positive staining in the undifferentiated PNET component of all tumors (10 of 10) and was rarely positive in the differentiated (ie, neuronal/glial) component (1 of 10; focal and weak); synaptophysin was slightly less sensitive in the undifferentiated component (12 of 13; often focal and weak) and also showed positivity in the neuronal/glial component (5 of 13). Glial fibrillary acidic protein and S100 were more frequently positive in the differentiated areas (83% and 77%, respectively) compared with undifferentiated areas (25% and 17%, respectively). CONCLUSIONS.­: SOX11 is a sensitive immunohistochemical marker for testicular PNET, particularly those lacking differentiation. Testicular PNETs often demonstrate glial and/or neuronal differentiation. Differentiation is marked by the acquisition of S100 and glial fibrillary acidic protein expression and SOX11 loss.

Insulinoma-associated Protein 1 (INSM1) Expression in Small Cell Neuroendocrine Carcinoma of the Urinary Tract.

Clinical guidelines state that neoadjuvant chemotherapy should be administered before surgery in muscle invasive urinary bladder small cell neuroendocrine carcinoma. Recently described marker insulinoma-associated protein 1 (INSM1) has been reported to be sensitive and specific for neuroendocrine differentiation, however, its efficacy in urinary tract small cell carcinoma is not well established. This study examines immunohistochemical expression of INSM1 on whole tissue sections of urinary tract small cell neuroendocrine carcinoma and compares INSM1 expression with established neuroendocrine markers. Immunohistochemical stains for CD56, INSM1, synaptophysin, and chromogranin were performed on 32 cases of small cell neuroendocrine carcinoma of the bladder. Staining was scored for intensity (0: no staining; 1: weak; 2: moderate; 3: strong) and proportion of cells stained (0: 0%; 1: >0% to ≤25%; 2: >25% to ≤50%; 3: >50% to ≤75%; 4: >75% to 100%). INSM1 was positive (intensity 1 to 3 or proportion 1 to 4) in 87% (28/32) of cases (20 with intensity 2 to 3, 17 with proportion 3 to 4). CD56, synaptophysin, and chromogranin were positive in 75% (24/32), 60% (19/32), and 44% (14/32) of cases, respectively. INSM1 was negative (n=4) or only showed weak intensity staining (n=7) in 34% (11/32) of cases. INSM1 is a sensitive marker of small cell neuroendocrine differentiation of the urinary tract. However, this study suggests that optimal utilization of INSM1 would be inclusion in a limited panel of stains rather than as a stand-alone screening marker given that it is negative or only shows weak intensity staining in a significant proportion of cases.

Cytomorphologic comparison of type 1 and type 2 papillary renal cell carcinoma: A retrospective analysis of 28 cases.

BACKGROUND: Papillary renal cell carcinoma (pRCC) is classified as type 1 or type 2 on the basis of histomorphologic features. Type 1 pRCC typically carries a better prognosis, and renal cell carcinoma is often diagnosed by fine-needle aspiration (FNA). Thus, this study was designed to characterize cytomorphologic features present in FNA cases that could be used to discriminate between type 1 and type 2 pRCC. METHODS: Electronic records of Indiana University were searched for pRCC FNA cases (2007-2018). Corresponding surgical pathology reports were reviewed to classify patients as having type 1 or type 2 pRCC. FNA slides were reviewed to assess cytomorphologic features (ie, nuclear grade; cell size; cytoplasmic volume and quality; and the presence of single cells, papillary clusters, nuclear grooves, foamy histiocytes, hemosiderin pigment, psammoma bodies, and hyaline globules). A semiquantitative score was assigned to each feature. The nuclear grade was assigned with the World Health Organization/International Society of Urological Pathology grading system. The cytomorphologic features of type 1 and type 2 pRCC were compared. RESULTS: Sixteen patients with type 1 pRCC and 12 patients with type 2 pRCC were included in the study. Type 2 pRCC had a higher nuclear grade, a higher volume of cytoplasm, and more granular cytoplasm. Type 1 pRCC more frequently had nuclear grooves and clear cytoplasm. The remaining features (ie, cell size, papillary clusters, single cells, foamy histiocytes, hemosiderin pigment, psammoma bodies, and hyaline globules) were not statistically significant. CONCLUSIONS: Nuclear grade, cytoplasmic volume and granularity or clarity, and nuclear grooves are cytomorphologic features that may aid in the distinction between type 1 and type 2 pRCC.

Plasmacytoid/diffuse urothelial carcinoma: a single-institution immunohistochemical and molecular study of 69 patients.

Accurate diagnosis of plasmacytoid urothelial carcinoma (PUC) is important given its poor prognosis and frequent presentation at high stage. We aim to assess the clinicopathological features, molecular aberrations, and follow-up data in a series of PUC cases from a single tertiary cancer center. Seventy-two urinary bladder, ureteral, and renal pelvic specimens with urothelial carcinoma with plasmacytoid differentiation were identified. Immunohistochemical stains were performed on 48 cases. Among urinary bladder origin markers, GATA3 was most sensitive (96%). Breast carcinoma markers (estrogen receptor, mammaglobin) were usually negative, but progesterone receptor stained 1 case (4%). Neuroendocrine markers CD56 and TTF-1 were each positive in 1 case (4% and 4%, respectively). Gastrointestinal adenocarcinoma marker CDX2 was positive in 4 cases (15%), but nuclear ß-catenin was negative in all cases. CD138 was positive in 83% and E-cadherin expression was lost in 57% of cases. Fluorescence in situ hybridization using the UroVysion Bladder Cancer Kit and FGFR3 mutational analysis using polymerase chain reaction were performed on 15 cases; deletion of chromosome 9p21 was common (60%), and FGFR3 mutations were detected in 60% of cases (5 cases had both deletion 9p21 and FGFR3 mutations). Cases were divided into 3 morphologic groups: classic (29%), desmoplastic (35%), and pleomorphic (36%). The 3 morphologic subtypes had distinct survival outcomes (P = .083), with median survival for all patients 18 being months versus 10 months for the desmoplastic group.

DOG1 immunohistochemical staining of testicular biopsies is a reliable tool for objective assessment of infertility.

Testicular biopsy may be a component of the work-up of male infertility. However, no reliable diagnostic tools are available for objective quantitative assessment of spermatogenic cells. It is well known that MAGE-A4 is selectively expressed in spermatogonia and our group has previously demonstrated that DOG1 differentially stains germ cells. Therefore, we performed DOG1 and a double stain cocktail (DOG1 and 57b murine monoclonal anti-MAGE-A4) immunohistochemical stains on 40 testicular infertility biopsies (10 each with active spermatogenesis, Sertoli cell-only, hypospermatogenesis, and maturation arrest), 25 benign seminiferous tubules from radical orchiectomies, and 5 spermatocytic tumors (ST). In biopsies/resections with active spermatogenesis, DOG1 stained spermatocytes and spermatids and was absent in spermatogonia, while MAGE-A4 stained spermatogonia and primary spermatocytes (weak). In hypospermatogenesis, DOG1 highlighted decreased spermatocytes/spermatids and MAGE-A4 highlighted decreased spermatogonia. DOG1 staining confirmed decreased to absent spermatocytes in maturation arrest and MAGE-A4 staining established the presence of preserved spermatogonia in all cases. All STs were negative for DOG1 and positive for MAGE-A4, while all Sertoli cell-only cases were negative for DOG1 and the double stain cocktail. In conclusion, we confirmed that DOG1 is expressed in spermatocytes and spermatids and MAGE-A4 highlights primarily spermatogonia. Usage of these stains facilitates confirmation of maturation arrest, assessment of the percentage of testis involvement in hypospermatogenesis and identification of mixed patterns. Finally, this study supports that the differentiation of STs is more closely related to spermatogonia than the more mature spermatocytes.

Fine-needle aspiration cytology of metastatic spindle cell follicular thyroid carcinoma: A case report.

Follicular thyroid carcinoma, spindle cell variant is extremely rare. The tumor is predominantly composed of spindle cells with a fusiform appearance that are arranged in intersecting fascicles. Fine-needle aspiration biopsy of this entity has not been previously described. We report a case of a 58-year-old woman who presented with metastasis to a left neck lymph node 15 years after the original diagnosis. Fine-needle aspiration cytology showed numerous bland, spindled to epithelioid cells with thin, elongated, and plump nuclei with finely granular chromatin and inconspicuous nucleoli. The tumor cells had a moderate amount of cytoplasm with occasional elongated cytoplasmic tails. The cells were arranged in irregular aggregates with a fascicular pattern or singly dispersed. The tumor cells demonstrated positive staining for pan-keratin, PAX8, thyroid transcription factor-1, and thyroglobulin, which confirmed thyroid primary origin.

Clinical Utility of Fluorescence In Situ Hybridization (FISH) for Deletion of Chromosome 3p in the Work-up of Renal Masses.

Chromosome 3p deletion is a well-established genetic aberration in clear cell renal cell carcinoma (RCC). We aimed to evaluate the clinical utility of 3p fluorescence in situ hybridization (FISH) on formalin-fixed paraffin-embedded tissue in surgical pathology specimens. 3p:3q <0.8 was established as the cut-off for 3p loss. The 2015 Medicare allowable billing rates were used to estimate the cost. Over 2.5 years (2013 to 2015), 3p FISH was performed on 18 cases per year. Among tested cases, 70% (30/43) were nephrectomies and 30% (14/43) metastases. 3p loss was detected in 44% (19/43) of cases, with a higher rate of loss in radical compared with partial nephrectomies (71% vs. 15%; P=0.003). A definitive RCC subtype was assigned in 65% (28/43) of cases. More partial nephrectomies had a definitive subtype assigned, compared with radical nephrectomies (92% vs. 59%; P=0.04), possibly related to more high-grade, high-stage tumors in submitted radical nephrectomies. Tested nephrectomies were most commonly diagnosed as clear cell (41%) or clear cell papillary RCC (32%). Half of unclassifiable RCCs had 3p loss (53%, 8/15). Annual 3p FISH costs were $3446.64, with 79% of costs from ancillary studies attributable to immunostains. 3p FISH was performed infrequently in nephrectomy specimens and was not cost prohibitive. RCC cases that are unclassifiable by morphology and other ancillary tests, but which have 3p FISH deletion may merit a comment in the pathology report, raising the possibility of clear cell RCC, as the oncologic approach may be altered despite the lack of a definitive RCC subtype.

Neuroglial Differentiation and Neoplasms in Testicular Germ Cell Tumors Lack Immunohistochemical Evidence of Alterations Characteristic of Their CNS Counterparts: A Study of 13 Cases.

Overgrowth of neuroglial tissue is rare in testicular germ cell tumors and mostly reported as isolated cases. We retrospectively reviewed 13 cases of testicular germ cell tumors from 2 institutions from 1995 to 2018. Hematoxylin and eosin slides were collected and reviewed. Immunohistochemistry was performed in all cases with available material. The series included 4 primary tumors and 9 metastases, including 8 retroperitoneal and 1 axillary lymph node (LN). The average age was 34 (range: 19 to 54). Five of the LN dissections were postchemotherapy, with one a recurrence 5 years after the initial diagnosis. The average tumor size for primary tumors was 5.15 cm (range: 1.7 to 7.3) and for metastases was 6.4 cm (range: 0.6 to 15). The largest size of the neuroglial component was 4.5 cm in the primary tumors and 7.5 cm in metastatic sites. The neuroglial component in the primary site was associated with pure teratoma (n=2) and with a mixed germ cell tumor (teratoma, seminoma, and embryonal carcinoma) (n=2). Cases involving LNs were associated with teratoma (n=4), seminoma (n=2), rhabdomyosarcoma (n=2), primitive neuroectodermal tumors (n=1), and high-grade sarcoma (n=1) (some with >1 other component). Two cases were pure glial tumor. Histologically, the neuroglial components included low-grade astrocytoma (n=3) (both with microcysts formation and pilocytic features), gemistocytic astrocytomas (n=3), anaplastic astrocytoma (n=2), ganglioglioma (n=1), glioblastoma (n=2), gliosarcoma (n=1), and developing central nervous system (CNS) (n=2). By immunohistochemistry, 13/13 (100%) cases were GFAP(+), 10/10 (100%) cases showed retained ATRX, 10/10 were IDH1 pR132H (-), 5/10 (50%) were p53 (+). A single case 1/10 (10%) was BRAF p.V600E (+), but a mutation was not identified by polymerase chain reaction. Follow-up was available in 6 patients; 4 were confirmed to have received chemotherapy with BEP; 1 had a local recurrence and the patient with gliosarcoma developed a lung metastasis morphologically similar to the gliosarcoma of the retroperitoneum. In conclusion, neuroglial differentiation and neoplasms are rare in testicular germ cell tumors and are most commonly associated with teratomas; they can be seen in primary and metastatic sites. They exhibit the full range of neuroglial differentiation including developing CNS to gliomas/glioneuronal tumors WHO grades I-IV. None of the cases showed results consistent with ATRX, IDH or BRAF alterations, suggesting they have different oncogenic mechanisms than their CNS counterparts.

World Health Organization (WHO)/International Society of Urological Pathology (ISUP) grading in fine-needle aspiration biopsies of renal masses.

BACKGROUND: Utilization of fine-needle aspiration (FNA) biopsy for the evaluation of renal masses has been increasing at our institution. At times diagnostic material on direct smears is superior to that in the cell block/core biopsy, therefore assigning an accurate nuclear grade in the cytopathology report would provide useful prognostic information. METHODS: Search of the pathology database identified renal FNAs performed during an 11-year period (2006-2017). Corresponding core biopsies and resections were identified. Cases with a diagnosis of primary renal neoplasia on FNA, core biopsy, and/or resection were included. Two pathologists reviewed all cases and assigned a World Health Organization (WHO)/International Society of Urological Pathology (ISUP) grade to each FNA, core biopsy, and resection case. RESULTS: A total of 162 kidney FNAs were identified. Primary renal neoplasia was diagnosed in 137 cases on core biopsy/resection. Among diagnostic FNAs of clear cell RCC and papillary RCC with core biopsy/resection specimens for re-review (n = 52), reviewers assigned a concordant WHO/ISUP grade to 83% (43/52) of cases. Among 9 cases with discrepant scores, all had a discrepancy of 1 grade and were undergraded on FNA. Using a two tier grading system (low vs. high grade), reviewers assigned a concordant grade to 88% (46/52) of cases. Among 6 cases with discrepant scores, all were classified as low grade (WHO/ISUP grade 2) on FNA versus high grade (WHO/ISUP grade 3) on resection. CONCLUSION: The WHO/ISUP grade assigned on FNA shows good concordance with subsequent resection/core specimens (83%), with all discrepant cases being undergraded by one grade.

Morphological spectrum of renal cell carcinoma, unclassified: an analysis of 136 cases.

AIMS: Renal cell carcinoma, unclassified (RCCU) is a category that includes a morphologically and biologically heterogeneous group of tumours that are unable to be diagnosed as other well-defined entities. We aim to describe the morphological findings of tumours within this category and to determine the most frequent morphological features leading to classification difficulty. METHODS AND RESULTS: One hundred and thirty-six cases of RCCU were examined. Patients ranged in age from 23 to 87 years. Seventy-seven patients were men and 59 were women. International Society of Urological Pathology (ISUP) grade was most commonly 3 (n = 66), followed by 2 (n = 42) and 4 (n = 28). Tumour size ranged from 0.6 to 24.9 cm. The American Joint Committee on Cancer (AJCC) pathological T categories included pT1a (n = 50), pT1b (n = 14), pT2a (n = 7), pT2b (n = 4), pT3a (n = 50) and pT4 (n = 9). Forty-four cases included lymph node(s), 41% of which (n = 18) had metastases. Tumours were assessed for a variety of histological features and assigned to the following morphological groups: predominantly oncocytoma/chromophobe RCC-like; clear cell RCC-like; papillary RCC-like; collecting duct-like; and pure sarcomatoid differentiation. The majority of the oncocytoma/chromophobe and clear cell RCC-like phenotypes were low stage (pT1 or pT2). The papillary RCC-like, collecting duct-like and pure sarcomatoid phenotypes were mainly high stage (pT3 or pT4). CONCLUSIONS: Renal cell carcinoma, unclassified is a term that encompasses tumours with a variety of morphological features and a wide biological spectrum. The most common source of diagnostic difficulty was tumours composed of predominantly eosinophilic cells.

Utility of GATA3 in the differential diagnosis of pheochromocytoma.

AIMS: GATA3 is a relatively new immunohistochemical marker which shows consistent nuclear expression in a variety of tumours, including breast and urothelial carcinoma. The staining pattern of GATA3 in adrenal lesions is not well established. We aim to describe the expression of GATA3 in adrenal tumours and determine if there is differential staining between pheochromocytoma and adrenal cortical carcinoma. METHODS AND RESULTS: A retrospective search was performed to identify 74 adrenal lesions which were tested immunohistochemically for GATA3 expression. GATA3 was negative in 90% of adrenal cortical carcinoma. In contrast, pheochromocytomas were frequently positive (71%), including benign pheochromocytoma, pheochromocytoma with features concerning for malignancy, malignant (metastatic) pheochromocytoma and composite pheochromocytoma with ganglioneuroma. Metastatic lung adenocarcinoma in the adrenal gland had occasional (36%) expression, while metastatic clear cell renal cell carcinoma in the adrenal gland did not express GATA3. CONCLUSION: As the most common pitfall in diagnosing adrenal cortical carcinoma is mistaking it for pheochromocytoma or vice versa, GATA3 may be useful in narrowing the differential diagnosis as a part of a panel of immunohistochemical markers. However, occasional GATA3 expression in the most common source of metastases within the adrenal gland, metastatic pulmonary adenocarcinoma, may confound the diagnosis due to the overlapping expression with pheochromocytoma and other carcinomas.

Ciliated hepatic foregut cyst: a report of 6 cases and a review of the English literature.

BACKGROUND: Ciliated hepatic foregut cyst (CHFC) is a rare cystic lesion most commonly identified in segment 4 of the liver that arises from the embryonic foregut. The classic histologic pattern is comprised of 4 distinct layers (inner ciliated epithelial lining, smooth muscle, loose connective tissue, fibrous capsule). Although rare, cases of metaplastic and malignant epithelial lining have been described in CHFC. METHODS: We report 6 additional cases of CHFC, one of which had gastric metaplasia of the cyst lining, and review all reported cases of CHFC in the English literature. We describe the clinicopathologic analysis of 6 cases, with selective immunohistochemical analysis on 1 case with gastric metaplasia. RESULTS: Cases occurred in 4 women and 2 men (average age 55 years, range 42 to 67 years). Cysts ranged in size from 0.7 to 17 cm (average 7.2 cm) and were grossly tan-pink to white with blood-filled contents. The majority were located in segment 4 of the liver, however 2 were located in the porta hepatis. Tumor serologies (CA19-9 and/or CEA) were performed in 3 cases; 1 case demonstrated elevated CA19-9, and 2 cases had laboratory values within normal limits. All cases showed the classic histologic findings, however one case additionally had extensive gastric metaplasia. CONCLUSIONS: In conclusion, CHFC is a rare diagnostic entity that should be considered in the differential diagnosis for cystic hepatic lesions, particularly those located in segment 4 of the liver. Metaplasia and squamous carcinoma can occur, therefore complete surgical excision is the recommended treatment.

Microphthalmia transcription factor immunohistochemistry for FNA biopsy of ocular malignant melanoma.

BACKGROUND: Microphthalmia transcription factor (MiTF) is a sensitive and specific immunohistochemistry (IHC) marker for malignant melanoma (MM) in surgical resections, but its utility in cytology specimens has not been extensively studied. METHODS: A search of the pathology database identified fine-needle aspiration biopsies signed out as MM or suspicious for MM (1998-2012). The final diagnosis and the IHC results were recorded, and all slides were re-reviewed. MiTF IHC (C5/D5 cocktail) was performed on alcohol-fixed, Papanicolaou-stained direct smears. Any amount of nuclear staining was considered positive. Staining was scored on a scale of 1 to 4 (1, 1%-24%; 2, 25%-49%; 3, 50%-74%; 4, 75%-100%). RESULTS: Two hundred seventy-four cases were diagnosed as MM, and 24 were diagnosed as suspicious for MM. IHC staining was performed for 25% (69 of 274) of the MM cases and for 33% (8 of 24) of the cases suspicious for MM. MiTF IHC of Papanicolaou slides was performed for 37% (101 of 274) of the MM cases (positive, 82% [83 of 101]; negative, 4% [4 of 101]; noncontributory, 14% [14 of 101]) and for 33% (8 of 24) of the cases suspicious for MM (positive, 38% [3 of 8]; noncontributory, 62% [5 of 8]). The majority of positive staining was scored as 3 or 4. The sensitivity of MiTF on Papanicolaou-stained slides was 95%. CONCLUSIONS: MiTF is a useful IHC stain for the evaluation of ocular MM, and it is effective when it is performed on alcohol-fixed, Papanicolaou-stained aspirate smears.

Genetic alterations in renal cell carcinoma with rhabdoid differentiation.

Renal cell carcinoma with rhabdoid differentiation (RCC-R) in adult patients is an aggressive variant of renal cancer with no known specific genetic alterations. The aim of this study was to characterize genome-wide genetic aberrations in RCC-R via utilization of high-density single-nucleotide polymorphism (SNP) arrays. We identified 20 cases of RCC-R, which displayed both clear cell renal cell carcinoma and rhabdoid histomorphologic components. DNA was extracted from formalin-fixed, paraffin-embedded tissue (from clear cell renal cell carcinoma and RCC-R areas from each case) and subjected to high-density SNP array assay. Genetic aberrations present in 10% of cases were considered significant. In areas with clear cell histomorphology, gains were most commonly observed in chromosomes 5q (66.7%, 10/15), 7 (46.7%, 7/15), and 8q (46.7%, 7/15); and losses were most commonly identified in chromosomes 14 (60%, 9/15), 8p (46.7%, 7/15), and 22 (46.7%, 7/15). In areas with rhabdoid differentiation, gains were most commonly observed in chromosome 7 (58.8%, 10/17); and losses were most commonly identified in chromosomes 9 (70.6%, 12/17), 14 (58.8%, 10/17), 4 (52.9%, 9/17), and 17p (52.9%, 9/17). Rhabdoid cells shared many chromosomal abnormalities and exhibited a greater number of copy number variations in comparison with coexisting clear cells. Loss of 11p was specific for rhabdoid differentiation, with loss found in 29.4% of rhabdoid components compared with 0% of clear cell areas. The greater number of overall genetic alterations in the rhabdoid cells and the shared genetic background between rhabdoid and clear cell areas suggest genetic evolution of the rhabdoid cells that correlates with histomorphologic progression.

Mismatch repair protein expression in 1049 endometrial carcinomas, associations with body mass index, and other clinicopathologic variables.

OBJECTIVE: Links between obesity, with its attendant estrogen abnormalities, and the endometrial carcinoma (EC) DNA Mismatch Repair Protein (MMR) system have recently been proposed. We investigated relationships between body mass index (BMI) and clinicopathological correlates including MMR expression in a large single institution EC cohort. METHODS: Clinical and pathological databases from 2007 to 2012 were used to identify consecutive hysterectomy specimens with EC. Univariate and multivariate analyses were used to explore relationships between BMI, age, stage, tumor type and immunohistochemical results for MLH1, PMS2, MSH2 and MSH6. RESULTS: 1049 EC were identified. Overall, BMI was higher amongst women with normal MMR (p=0.002). However, when stratified by age and specific MMR, statistically significant differences localized exclusively to women <50years old with loss of MSH2 and/or MSH6 (p=0.003 and p=0.005 respectively). Higher BMI correlated with endometrioid FIGO 1 and 2 tumors (p<0.001) and with stage 1a (p<0.001). Conversely, MMR abnormalities did not show significant associations with stage (p=0.302) or histologic grade (p=0.097). CONCLUSIONS: BMI showed statistically significant associations with MMR expression, tumor grade and stage amongst 1049 consecutive EC. Obesity correlates with lower grade and stage EC. A link between BMI and maintenance of the MMR system is not supported by our data because the only statistically significant association occurred in women <50years old with MSH2 and/or MSH6 abnormalities where Lynch syndrome related cases are expected to cluster.