The American Journal of Surgical Pathology This is an RSS file. You can use it to subscribe to this data in your favourite RSS reader or to display this data on your own website or blog.

Atypical Teratoid/Rhabdoid Tumor (AT/RT) With Molecular Features of Pleomorphic Xanthoastrocytoma
In conclusion, the possibility of AT/RT with molecular features of PXA needs to be taken into account and warrants molecular characterization of AT/RT especially in older children. Since treatments targeting mutated BRAF are available, identification of such cases may also have therapeutic consequences. (Source: The American Journal of Surgical Pathology)
Source: The American Journal of Surgical Pathology - August 22, 2021 Category: Pathology Tags: Original Articles Source Type: research

NUT Is a Specific Immunohistochemical Marker for the Diagnosis of YAP1-NUTM1-rearranged Cutaneous Poroid Neoplasms
YAP1-NUTM1 fusion transcripts have been recently reported in poroma and porocarcinoma. NUTM1 translocation can be screened by nuclear protein in testis (NUT) immunohistochemistry in various malignancies, but its diagnostic performance has not been thoroughly validated on a large cohort of cutaneous epithelial neoplasms. We have evaluated NUT immunohistochemical expression in a large cohort encompassing 835 cases of various cutaneous epidermal or adnexal epithelial neoplasms. NUT expression was specific to eccrine poromas and porocarcinoma, with 32% of cases showing NUT expression. All other cutaneous tumors tested lacked N...
Source: The American Journal of Surgical Pathology - August 22, 2021 Category: Pathology Tags: Original Articles Source Type: research

Human Leukocyte Antigen Class I Deficiency in Gastric Carcinoma: An Adaptive Immune Evasion Strategy Most Common in Microsatellite Instable Tumors
This study included 58 MSI, 44 EBV-positive, and 107 non-EBV non-MSI tumors for comparison. The frequency of HLA-I deficiency (≥1% tumor cells) was significantly higher in MSI tumors (52%) compared with EBV-positive tumors (23%) and the other tumors (28%). In contrast, PD-L1 expression levels were highest in EBV-positive tumors, followed by MSI tumors, with the lowest prevalence in the other tumors in both Tumor Proportion Score and Combined Positive Score. HLA-I deficiency was significantly more frequent in advanced tumors (pT2-4) than in early tumors (pT1) in MSI and non-EBV non-MSI subtypes. In addition, the degree of...
Source: The American Journal of Surgical Pathology - August 22, 2021 Category: Pathology Tags: Original Articles Source Type: research

Primary Cilia Are Preserved in Cellular Blue and Atypical Blue Nevi and Lost in Blue Nevus–like Melanoma
Distinguishing cellular blue nevi (CBNs) and atypical CBNs from blue nevus–like melanoma (BNLM) can be diagnostically challenging. Immunohistochemistry may inform the diagnosis in a subset of cases but is not always diagnostic. Further, ancillary molecular testing is expensive and often requires significant tissue to complete. Primary cilia are cell-surface organelles with roles in signal transduction pathways and have been shown to be preserved in conventional melanocytic nevi but lost in melanoma. Immunofluorescence staining of primary cilia can be performed using a single standard-thickness formalin-fixed paraffin-emb...
Source: The American Journal of Surgical Pathology - August 22, 2021 Category: Pathology Tags: Original Articles Source Type: research

IDH2 R172 Mutations Across Poorly Differentiated Sinonasal Tract Malignancies: Forty Molecularly Homogenous and Histologically Variable Cases With Favorable Outcome
IDH2 R172 mutations occur in sinonasal undifferentiated carcinoma (SNUC), large-cell neuroendocrine carcinoma (LCNEC), sinonasal adenocarcinomas, and olfactory neuroblastoma (ONB). We performed a clinical, pathologic, and genetic/epigenetic analysis of a large IDH2-mutated sinonasal tumor cohort to explore their distinct features. A total 165 sinonasal/skull base tumors included 40 IDH2 mutants studied by light microscopy, immunohistochemistry, and genome-wide DNA methylation, and 125 IDH2 wild-type tumors used for comparison. Methylation profiles were analyzed by unsupervised hierarchical clustering, t-distributed stochas...
Source: The American Journal of Surgical Pathology - August 22, 2021 Category: Pathology Tags: Original Articles Source Type: research

Intraoperative Frozen Section Biopsy of Uterine Smooth Muscle Tumors: A Clinicopathologic Analysis of 112 Cases With Emphasis on Potential Diagnostic Pitfalls
Frozen sections of uterine smooth muscle tumors are infrequently required, and related diagnostic difficulties are seldom discussed. We analyzed the clinicopathologic features of 112 frozen sections of uterine smooth muscle tumors and determined the accuracy, reasons for deferrals, and causes of interpretational errors. Most patients (median age, 45 y) presented with pelvic mass symptoms (53%). The main reasons for a frozen section examination were an abnormal gross appearance including loss of the usual whorled pattern of leiomyoma (36 cases, 32.1%), and intraoperative discovery of an abnormal growth pattern and extraut...
Source: The American Journal of Surgical Pathology - August 22, 2021 Category: Pathology Tags: Original Articles Source Type: research

ALK Rearrangements Characterize 2 Distinct Types of Salivary Gland Carcinomas: Clinicopathologic and Molecular Analysis of 4 Cases and Literature Review
The majority of salivary gland carcinomas are characterized by recurrent gene fusions that proved highly valuable diagnostically, but only rarely of therapeutic impact. Most of these fusion-positive carcinomas belong to the low-grade or intermediate-grade biological category. To date, only 5 cases of salivary gland carcinomas carrying an oncogenic ALK fusion have been reported in 4 recent studies, but their phenotypic spectrum and their nosological classification remain uncharacterized. We herein describe in detail the clinicopathologic and molecular features of 4 ALK–fusion-positive salivary carcinomas and review previo...
Source: The American Journal of Surgical Pathology - August 22, 2021 Category: Pathology Tags: Original Articles Source Type: research

Pheochromocytoma: A Clinicopathologic and Molecular Study of 390 Cases From a Single Center
Pheochromocytomas are rare neuroendocrine tumors arising from chromaffin cells in the adrenal medulla. They may occur sporadically or in the context of hereditary syndromes. All pheochromocytomas are considered to have malignant potential (defined as risk of metastasis, not local invasion). The use of grading systems with incorporated clinical and histopathologic parameters can help but not definitively predict the metastatic potential of pheochromocytomas. The recent discovery of susceptibility genes provided new insights into the pathogenesis and introduced additional approaches to estimate the metastatic risk of pheochr...
Source: The American Journal of Surgical Pathology - August 22, 2021 Category: Pathology Tags: Original Articles Source Type: research

Primary Giant Cell Tumors of the Lung: A Clinicopathologic and Immunohistochemical Study of 3 Cases
Three cases of primary giant cell tumors of the lung akin to those described in the soft tissues are presented. The patients are 3 men between the ages of 43 and 54 years who presented with nonspecific symptoms of cough, chest pain, and shortness of breath. None of the patients had any prior history of malignancy anywhere else. Diagnostic imaging disclosed the presence of an intrapulmonary mass. All the patients underwent lobectomy. Grossly, the tumors were described as solid, slightly hemorrhagic, and measuring between 1.8 and 2.4 cm in greatest diameter. Histologically, the tumors were characterized by a dual populatio...
Source: The American Journal of Surgical Pathology - July 26, 2021 Category: Pathology Tags: Original Articles Source Type: research

Lymphadenopathy Associated With Neutralizing Anti-interferon-gamma Autoantibodies Could Have Monoclonal T-cell Proliferation Indistinguishable From Malignant Lymphoma and Treatable by Antibiotics: A Clinicopathologic Study
Early recognition of adult-onset immunodeficiency associated with neutralizing anti-interferon gamma autoantibodies (anti-IFNγ Abs) remains difficult, and misdiagnoses have been reported. Although febrile lymphadenopathy is among the most common initial manifestations of this disorder, no comprehensive clinicopathologic analysis of lymphadenopathy in patients with anti-IFNγ Abs has been reported. Here, we describe 26 lymph node biopsy specimens from 16 patients. All patients exhibited concurrent disseminated nontuberculous mycobacterial infections, and 31% received a tentative diagnosis of lymphoma at initial presentatio...
Source: The American Journal of Surgical Pathology - July 26, 2021 Category: Pathology Tags: Original Articles Source Type: research

Clinical Utility of Anchored Multiplex Solid Fusion Assay for Diagnosis of Bone and Soft Tissue Tumors
Sarcoma diagnosis has become increasingly complex, requiring a combination of morphology, immunohistochemistry, and molecular studies to derive specific diagnoses. We evaluated the role of anchored multiplex polymerase chain reaction–based gene fusion assay in sarcoma diagnostics. Between 2015 and 2018, bone and soft tissue sarcomas with fusion assay results were compared with the histologic diagnosis. Of 143 sarcomas tested for fusions, 43 (30%) had a detectable fusion. In review, they could be classified into 2 main categories: (1) 31 tumors with concordant morphologic and fusion data; and (2) 12 tumors where the fusio...
Source: The American Journal of Surgical Pathology - July 26, 2021 Category: Pathology Tags: Original Articles Source Type: research

ISUP Consensus Definition of Cribriform Pattern Prostate Cancer
The presence of a cribriform pattern is now recognized as a clinically important, independent adverse prognostic indicator for prostate cancer. For this reason the International Society of Urological Pathology (ISUP) recently recommended its inclusion in standard reporting. In order to improve interobserver agreement as to the diagnosis of cribriform patterns, the ISUP assembled an international panel of 12 expert urogenital pathologists for the purpose of drafting a consensus definition of cribriform pattern in prostate cancer, and provide their opinions on a set of 32 images and on potential diagnostic criteria. These im...
Source: The American Journal of Surgical Pathology - July 26, 2021 Category: Pathology Tags: Original Articles Source Type: research

SP142 PD-L1 Scoring Shows High Interobserver and Intraobserver Agreement in Triple-negative Breast Carcinoma But Overall Low Percentage Agreement With Other PD-L1 Clones SP263 and 22C3
SP142 programmed cell death ligand 1 (PD-L1) status predicts response to atezolizumab in triple-negative breast carcinoma (TNBC). Prevalence of VENTANA PD-L1 (SP142) Assay positivity, concordance with the VENTANA PD-L1 (SP263) Assay and Dako PD-L1 IHC 22C3 pharmDx assay, and association with clinicopathologic features were assessed in 447 TNBCs. SP142 PD-L1 intraobserver and interobserver agreement was investigated in a subset of 60 TNBCs, with scores enriched around the 1% cutoff. The effect of a 1-hour training video on pretraining and posttraining scores was ascertained. At a 1% cutoff, 34.2% of tumors were SP142 PD-L1 ...
Source: The American Journal of Surgical Pathology - July 26, 2021 Category: Pathology Tags: Original Articles Source Type: research

Morphologic and Molecular Findings in Myxoid Hepatic Adenomas
Myxoid hepatic adenomas are a rare subtype of hepatic adenomas with distinctive deposition of extracellular myxoid material between the hepatic plates. A total of 9 cases were identified in 6 women and 3 men with an average of 59±12 years. The myxoid adenomas were single tumors in 5 cases and multiple in 4 cases. In 1 case with multiple adenomas, the myxoid adenoma arose in the background of GNAS-mutated hepatic adenomatosis. Myxoid hepatic adenomas had a high frequency of malignant transformation (N=5 cases). They were characterized at the molecular level by HNF1A inactivating mutations, leading to loss of LFABP protein ...
Source: The American Journal of Surgical Pathology - July 26, 2021 Category: Pathology Tags: Original Articles Source Type: research

Liver Pathology, Including MOC31 Immunohistochemistry, in Congenital Tufting Enteropathy
Congenital tufting enteropathy (CTE) is a rare heritable cause of intractable diarrhea due to EPCAM mutation. Pathologic findings include intestinal villous atrophy, tufted discohesive tear-drop-shaped epithelium, and a normal brush border. In affected patients, absent intestinal epithelial cell adhesion molecule (EpCAM) expression results in loss of MOC31 immunostaining. CTE liver pathology has not yet been described. We identified CTE patients with liver biopsies and reviewed clinicopathologic material including MOC31 immunohistochemistry. Three CTE patients had 4 liver core biopsies (at ages 1, 5, 7, and 16 y), 2 for ...
Source: The American Journal of Surgical Pathology - July 26, 2021 Category: Pathology Tags: Original Articles Source Type: research