Divergent Lineage Markers in Anaplastic Thyroid Carcinoma.

Anaplastic thyroid carcinoma (ATC) often results from dedifferentiation of differentiated thyroid carcinoma (DTC), and the diagnosis is not difficult, as the tumor is seen to progress from a recognized DTC. However, in some cases, the diagnosis based on biopsy of limited tissue or resection of a completely undifferentiated tumor relies on immunohistochemical biomarkers and is usually a diagnosis of exclusion. To examine the biomarker profile of ATC and to determine whether divergent lineage markers can complicate this process, we examined the expression of a number of biomarkers in a series of ATCs. Cases retrieved from the department laboratory information system were included if there was evidence of an accurate diagnosis based on the presence of a coexisting or antecedent DTC or in cases where the immunoprofile was consistent with thyroid origin in a non-equivocal clinical setting. Questionable cases were excluded. We identified 36 cases for analysis. Tissue sections were stained for PAX8, TTF1, BRAFV600E, NRASQ61R, TRK, and p53, as well as p40, CDX2, SATB2, GATA3, CD117, CD163, SALL4, SMARCA4, PRAME, SOX10, ERG and HEPPAR1. As expected, all 36 ATCs were negative for TTF1 except for one showing focal, weak expression. Thirteen expressed PAX8 with variable intensity. BRAFV600E was positive in 10/34 tumors and equivocal in 3; NRASQ61R was positive in 12, and TRK was positive in 1 case. Staining for p53 was diffusely positive in 14 and completely negative in 19, with only 3 cases showing a wild-type pattern. We found aberrant expression of GATA3 in 11/36 cases, SATB2 in 8/36, CD117 in 2/35, and SALL4 in 1/30. CD163 expression was identified in tumor cells in 10/30 cases with variable intensity; in the other tumors, interpretation was obscured by abundant histiocytes. P40 was positive in 5 cases with squamoid morphology. CDX2 was negative in 35 tested cases. PRAME was identified in 1 of 33 cases. Stains for SOX10, ERG, and HEPPAR1 were negative in 33 cases. Twenty tested cases showed retained SMARCA4 expression. We conclude that ATCs express a number of divergent lineage markers that can cause diagnostic dilemmas, as they are also features of other tumors in the differential diagnosis of high-grade midline neck malignancies.

Discordance Between Conventional and Detailed Lymph Node Analysis in Resected, Node-negative Pancreatic or Ampullary Adenocarcinomas and Association With Adverse Survival Outcomes: A Single-institution Analysis.

OBJECTIVE: To assess the frequency of occult metastases (OM) in patients with resected pancreatic ductal adenocarcinoma (PDAC) or ampullary adenocarcinoma (AA) discovered on detailed pathologic examination on lymph nodes (LNs) previously considered negative by conventional analysis and to examine the association between OM and overall survival (OS). BACKGROUND: Poor prognosis of patients with no pathologic evidence of LN metastases may be due to OM that is not detected on conventional LN analysis. METHODS: Patients with LN-negative resected PDAC or AA (2010-2020) were identified from our institutional database. Original hematoxylin and eosin ( H and E ) slides were reanalyzed. In addition, selected LN were analyzed by H and E (3 sections/LN) and pan-cytokeratin (AE1-AE3/PCK26) immunohistochemistry. RESULTS: A total of 598 LNs from 74 LN-negative patients were reexamined. Nineteen patients (25.7%) had OM; 9 (47.4%) were found with immunohistochemistry but not on H and E . The number of positive LNs ranged from 1 to 3. No clinicodemographic, pathologic, or treatment-related factors were associated with OM. On conventional LN analysis, 3/19 patients (15.8%) had stage IA, 9/34 (26.5%) had stage IB, and 7/19 (36.8%) had stage IIA. On detailed LN analysis, 11/19 patients (57.9%) were upstaged to IIB, whereas 8/19 (42.1%) had isolated tumor cells only (N0i+). OM was associated with shorter OS (median OS: 22.3 vs 50.5 months; hazard ratio=3.95, 95% CI: 1.58-9.86). CONCLUSIONS: There is a 26% discordance rate between conventional and detailed LN pathologic analysis in resected PDAC and AA. The presence of OM is associated with shorter OS.

Clinicopathologic Characteristics of Young Patients with Oral Squamous Cell Carcinoma.

Oral squamous cell carcinoma (OSCC) occasionally occurs in young patients and is likely to be distinct from OSCC in older patients. In this retrospective study, we described the clinicopathologic features and outcome of 150 OSCCs that were diagnosed in patients 40-year-old or younger. Most patients (63%) were non-smokers. The most common site of the primary tumor was oral tongue (n = 131, 87%), followed by gingiva (n = 9), buccal mucosa (n = 8) and lip (n = 2). The median patients' age at presentation was 34 (range: 16-40). Seven patients (5%) had Fanconi anemia with the gingiva being the most common location (4/7, 57%). All OSCCs were of keratinizing type. All cases tested for high-risk HPV (n = 34) were negative. On univariate analysis, high tumor budding was associated with decreased overall survival (OS) and distant metastasis free survival (DMFS), pattern of invasion correlated with OS and tumors with high stromal tumor infiltrating lymphocytes (sTIL) were associated with improved locoregional recurrence free survival (LRFS). Compared with patients 31 to 40-year-old, OSCC in the younger group was associated with significant less alcohol consumption (p = 0.011) and decreased DSS (p = 0.003) and DMFS (p = 0.023). On multivariate analysis, younger age (30 years or younger) was an independent prognostic factor for worse OS and DSS, whereas histologic grade was an independent prognostic factor for DSS. In summary, most OSCC in young patients occurred in non-smokers and did not occur in association with Fanconi anemia. Independent prognostic factors included age at presentation (30 years or younger) for OS and DSS, and histologic grade for DSS.

Immunochemistry in the work-up of mesothelioma and its differential diagnosis and mimickers.

The differential diagnosis in cellular effusions with cytological atypia often includes malignant mesothelioma (MM), reactive mesothelial proliferation, and malignancies of metastatic origin, particularly carcinomas. The International Reporting System for Serous Fluid recently established guidelines for reporting MM. In conjunction with the cytomorphologic evaluation, the role of immunochemistry (IC) was emphasized as a very useful tool in the workup of serous fluids, especially with the availability of novel markers. Utilizing a panel of markers, IC allows the characterization of the cells, whether mesothelial or not, and when mesothelial origin is established, IC can frequently assist in delineating its benign or malignant nature. IC can also confirm metastatic disease, allowing the identification of the primary origin in most cases. This review summarizes the current status of IC and its role in the diagnosis of MM and its differential diagnosis in serous fluids.

Rosai dorfman disease: A rare presentation of primary ureteral involvement with concurrent sarcoidosis.

Rosai-Dorfman disease is a rare condition with poorly understood pathogenesis at this time. Although it often involves the lymph nodes, it can present nearly anywhere at extranodal sites. Patients are frequently asymptomatic, but surgical debulking is currently the only method of treatment that has shown benefit for patients requiring intervention. This case report discusses a unique presentation of Rosai-Dorfman disease involving the ureter of a 49-year-old woman with known history of sarcoidosis, discovered incidentally on routine CT scan.

Malignant Peritoneal Mesothelioma in the setting of a Ventriculo-Peritoneal Shunt: A novel clinical presentation.

We report a case of malignant peritoneal mesothelioma (MPM) in a 31-year-old male with history of cerebral palsy, hydrocephalus, and ventriculoperitoneal shunt (VPS) placed since infancy. He presented with fever, abdominal pain and distension. Computed tomography scan revealed a thick-walled rim-enhancing fluid collection, interpreted as pseudocyst. Intraoperatively, diffuse nodular peritoneal thickening with adhesions was demonstrated. The resection specimen consisted of multiple membranous fragments displaying firm nodules. Microscopic examination revealed a tumefactive malignant-appearing epithelioid proliferation involving the peritoneum, focally invading the underlying fat. Immunohistochemically, the tumor cells expressed keratin AE1/AE3, CK7, CK5/6, Calretinin, WT1 and D2-40, and were negative for CEA and MOC31. The findings were consistent with MPM, epithelioid type. The patient's condition continued to decline with increasing abdominal distension during the month following the original diagnosis. While atypical mesothelial hyperplasia has been described in association with long standing VPS, well-documented cases of MPM have not been previously reported in such context.

Is ALK-gene rearrangement overlooked in primary gastrointestinal T-cell lymphomas? About two cases.

A 41-year-old male patient with a history of ankylosing spondylitis and Crohn disease, treated with immunomodulators and disease-modifying drugs, was diagnosed with a primary intestinal T-cell lymphoma that followed a 7.5-year-course. This transmural proliferation lacked cytological characteristics of anaplastic large cell lymphoma (ALCL), and was CD8-positive, and CD30- and anaplastic lymphoma kinase (ALK)-negative by immunohistochemistry (IHC). However, ALK-gene rearrangement (ALK-gr) was detected by fluorescence in situ hybridization (FISH) in both initial and persistent disease. The possibility of indolent T-cell lymphoproliferative disease of the gastrointestinal tract with atypical features (transmural involvement) related to ALK-gr was suggested. A previous case of aggressive 'enteropathy-associated ALCL' in the context of celiac disease was recently reported, which also lacked anaplastic morphology, and where CD30 and ALK expression was incidentally demonstrated by IHC, and ALK-gr subsequently confirmed by FISH. These two recent cases represent two distinct rare entities pertaining to the group of primary intestinal T-cell lymphomas, and they both show unexpected ALK-gr. This suggests that ALK-gr has been overlooked in the group of primary intestinal T-cell lymphomas. Performing IHC and FISH tests for ALK-gr in primary gastrointestinal T-cell lymphomas might be of importance, particularly with the advancement of targeted therapy that could impact treatment and prognosis.

Micronodular thymic neoplasms: case series and literature review with emphasis on the spectrum of differentiation.

We report nine cases of micronodular thymoma with lymphoid B-cell hyperplasia and one case of micronodular thymic carcinoma with lymphoid hyperplasia from our institution. For a better understanding of these rare tumors, clinical records, and histological features of these cases were reviewed, with detailed review of additional 64 literature cases of micronodular thymic neoplasms. The joint analysis identified 64 cases of micronodular thymoma with lymphoid B-cell hyperplasia and 9 cases of micronodular thymic carcinoma with lymphoid hyperplasia. Both groups revealed slight male predilection, with male:female ratio of 1.3:1 and 5:4, and occurred at >40 years of age, with a mean of 64 (41-83) and 62 (42-78) years, respectively. Myasthenia gravis was noted in 3/64 (5%) and 1/9 (11%) patients, respectively. Other systemic, disimmune, or hematologic disorders were noted in 6/64 (9%) and 1/9 (11%) patients, respectively. Components of conventional thymoma were reported in 11/64 (17%) micronodular thymomas with lymphoid B-cell hyperplasia, with transitional morphology between the two components in most of them. Cellular morphology was predominantly spindle in micronodular thymoma with lymphoid B-cell hyperplasia when specified (30/43), and epithelioid in micronodular thymic carcinoma with lymphoid hyperplasia (6/9), and cytological atypia was more encountered in the latter. Dedifferentiation/transformation from micronodular thymoma with lymphoid B-cell hyperplasia to micronodular thymic carcinoma with lymphoid hyperplasia seems to occur in a small subset of cases. Three cases of micronodular thymomas with lymphoid B-cell hyperplasia were described with co-existent low-grade B-cell lymphomas. Follow-up data were available for 30 micronodular thymomas with lymphoid B-cell hyperplasia and 6 micronodular thymic carcinomas with lymphoid hyperplasia, with a mean of 47 (0.2-180) months and 23 (3-39) months, respectively. Patients were alive without disease, except for five micronodular thymoma with lymphoid B-cell hyperplasia patients (dead from unrelated causes), and one micronodular thymic carcinoma with lymphoid hyperplasia patient (dead of disease).

One hundred thirteen consecutive transgastric liver biopsies for hepatic parenchymal diseases: a single-institution study.

The transgastric approach is a novel method for obtaining liver biopsies in patients undergoing upper gastrointestinal endosonography. Avoidance of vascular puncture and ability to acquire tissue in patients with obesity or ascites offers a practice niche for this technique. Although several series have reported on specimen adequacy, biopsy core length, and number of portal tracts, none has addressed the diagnostic challenges presented by the fragmented nature of these specimens. We systematically evaluated 113 transgastric liver biopsies obtained for diagnosis of parenchymal liver disease by 3 needle types and compared them with 100 percutaneous and 100 transjugular liver biopsies, respectively. Parameters recorded were number of tissue cores, sizes of longest and shortest cores, numbers of complete and incomplete portal tracts, morphologic characteristics, and adequacy of specimen for diagnosis and staging. In contrast to percutaneous and transjugular liver biopsies, transgastric biopsies often contained >10 tissue fragments and smaller tissue cores. In addition, 2 of the 3 types of transgastric needles obtained less numbers of complete portal tracts. Transjugular biopsies were also smaller and contained less number of complete portal tracts than percutaneous specimens but, unlike transgastric biopsies, only rarely contained >10 tissue fragments. Specimen adequacy for diagnosis and staging was 80%, 100%, and 98% for transgastric, percutaneous, and transjugular biopsies, respectively. Difference in specimen adequacy is related to tissue fragmentation of transgastric liver biopsies rather than biopsy core length or numbers of complete portal tracts. Tissue fragmentation is particularly challenging for staging chronic liver disease.

Torsion of the gonad in the pediatric population: spectrum of histologic findings with focus on aspects specific to neonates and infants.

Histopathologic findings of gonadal torsion in neonates and infants (GTNI) are poorly defined in the literature. We describe herein the histopathologic spectrum of GT with emphasis on the pediatric population and on features specific for NI (≤1 year of age). Twenty-four cases of GTNI (6 females/18 males), 33 cases of GT in an older pediatric population (OPP) (19 females/14 males), and 43 cases of GT in adults (35 females/8 males) were found in our pathology files between 2003 and 2011. Our findings disclosed 2 categories of GT: 1) the group of NI, and 2) that of OPP and adults who share a similar presentation as acute hemorrhagic necrosis of the gonad. Although findings in NI were rather uniform, a few differences were demonstrated between the 2 genders. All GTNI revealed calcifications, fibrosis, siderophages, and extensive necrosis. However, prominent necrotizing palisaded granulomatas were seen in most (4 of 6) cases of ovarian torsion but not in the testicular counterpart. Furthermore, complete gonad regression was encountered exclusively in neonatal testicular torsion cases. In conclusion, 1) pathologic findings in GT are distinctly different between NI and OPP, the latter being more comparable to adults, presenting with acute hemorrhagic necrosis; 2) the distinctive findings in GTNI of both genders include calcifications, siderophages, and fibrosis, in addition to background necrosis; 3) of particular note, complete gonadal regression is seen only in the testis in GTNI; and 4) necrotizing palisaded granulomatas are unique to the ovarian subgroup and are often extensive, obscuring the nature of the process.

Micropapillary carcinoma: new variant of prostatic acinar adenocarcinoma.

A micropapillary variant of prostatic acinar adenocarcinoma has not been reported in the literature. Herein, we report a case of a 50-year-old patient who presented with an elevated prostate-specific antigen concentration and was subsequently diagnosed with prostatic acinar adenocarcinoma on biopsy. Radical prostatectomy specimen revealed prostatic carcinoma with Gleason score 4 + 5  =  9/10, with micropapillary component constituting 80% of tumor volume. Immunohistochemical studies of the prostate carcinoma showed a homogeneously positive prostate-specific antigen and α-methylacyl-CoA racemase, high-molecular-weight cytokeratin, and p63 protein cocktail pattern of staining in both micropapillary and conventional components. Pelvic lymph nodes were negative for metastatic disease. In contrast to the aggressive behavior of micropapillary carcinomas of other organs, the disease in our patient has thus far followed a more benign course, with low stage on presentation and a 2-year follow-up free of disease. However, prognostic correlation should be established on large series in order to assign this variant to a grade category within the Gleason scheme.