International Journal of Surgical Pathology最新文献

Sinonasal lymphoepithelial carcinoma (SNLEC) is a rare malignancy composed of poorly differentiated epithelial cells with syncytial morphology and a variably dense lymphoplasmacytic infiltrate. Nearly all reported tumors are associated with Epstein-Barr virus (EBV), which can be demonstrated by in situ hybridization for EBV-encoded RNA. We present a diagnostically challenging lesion of SNLEC in a 60-year-old woman with a right nasal cavity mass and cervical lymphadenopathy. Histological sections showed sheets of malignant cells with vesicular nuclei, prominent nucleoli, and indistinct borders. Immunohistochemistry revealed diffuse nuclear expression of insulinoma-associated protein 1 (INSM1), raising initial concern for poorly differentiated neuroendocrine carcinoma. However, the tumor lacked classic light microscopic features of neuroendocrine differentiation, was negative for synaptophysin and chromogranin, and, most importantly, was strongly positive for EBV, findings that argue against neuroendocrine carcinoma and support the diagnosis of SNLEC. This case report highlights a potential diagnostic pitfall, as INSM1 expression may be misleading in EBV-associated carcinomas lacking true neuroendocrine differentiation. Integration of morphology, immunoprofile, and EBV status is essential to avoid misclassification.

Biliary tract cancer has a poor prognosis, with systemic chemotherapies showing limited benefit. New therapeutic targets are urgently needed to improve the prognosis of biliary tract cancer. Since HER2-targeted therapies have shown promising results for biliary tract cancer, accurate assessment for HER2 status in biopsy samples, which are often the only diagnostic material available for inoperable lesions, is crucial. This study assessed HER2 expression in 108 samples (surgical specimens and biopsies) from 84 biliary tract cancer patients. HER2 IHC scores of 2+ (equivocal) and 3+ (overexpression) were observed in 11% (7/65 specimens) and 9% (6/65 specimens) of biopsy specimens, and 7% (3/43 specimens) and 7% (3/43 specimens) of surgical specimens, respectively. The HER2 concordance rate between matched biopsy and surgical specimens was 75%. The results suggest that HER2 assessment in biopsies may reliably predict HER2 status across the tumor, supporting treatment decisions. However, the study acknowledges certain limitations, including the need for additional in situ hybridization tests in lesions of ambiguous HER2 overexpression. In conclusion, the HER2 status on biopsy specimens may reflect the HER2 status of the whole lesion and could be used to select suitable patients for neoadjuvant HER2-targeted therapy.

The finding of Pacinian corpuscles (PCs) in association with the prostate gland is an anatomical rarity. We present the largest series to date of 23 peri-prostatic PCs from 14 patients identified during routine reporting of radical prostatectomy and cystoprostatectomy specimens with or without pelvic lymph node dissection. The clinicopathological features of this perplexing anatomical structure, including the location, size, shape, immunohistochemical and ultrastuctural findings are thoroughly investigated. We also identify for the first time the clustered appearance of PCs in 2 patients consistent with PC hyperplasia.

Gastrointestinal Kaposi sarcoma (GI-KS) in inflammatory bowel disease (IBD) is exceedingly rare. Herein, we report 6 biopsy-proven HHV8(+)-GI-KS in IBD patients with a review of the literature. Our patients include 5 men and 1 woman, 26 to 41 (mean = 34) years, 3 Crohn disease, 3 ulcerative colitis (UC), 4 HIV(+), and 2 HIV(-), with 5 of 6 (83%) diagnosed with GI-KS on endoscopic biopsy. Tumor sites included stomach and rectum (2/6; 33% each), and duodenum and left colon (1/6; 17% each). In 1 HIV(-) patient, GI-KS was missed on the initial biopsy and identified at total colectomy for "refractory" UC; besides the rectal tumor, the appendix and a lymph node were also involved. Endoscopy showed flat or mass-like lesions (3/6; 50% each). Histologically, GI-KS shows a classic morphology of spindle cell proliferation in 4 (67%) and subtle paucicellular variants in 2 (33%) patients. All patients were treated with chemotherapy or surgery, with highly active antiretroviral therapy added for all HIV(+) patients. On follow up (mean = 64.7, median = 55.5, range = 6-162 months), all patients were alive with endoscopic remission (3/5; 50%), stable or improved IBD, and no disseminated disease. Fifteen patients with HHV8(+) GI-KS were previously reported, with 54% diagnosed only after surgery, suggesting a high false-negative rate on endoscopic biopsy. In conclusion, GI-KS rarely occurs in IBD, appears to have a high risk of being missed on endoscopic biopsy, has a good outcome, and should be considered in patients with "refractory" IBD. Multiple sites of involvement do not portend a worse prognosis. Accurate diagnosis is essential to initiate appropriate therapy, since IBD immunosuppressive regimens may exacerbate GI-KS.

Primary head and neck mucosal melanoma is a rare and aggressive malignancy distinct from cutaneous melanoma, with no known association with UV exposure and a poorly understood pathogenesis. Diagnosis is often challenging due to its morphologic diversity and potential overlap with other malignancies. A subset of mucosal melanomas has been reported to express neuroendocrine markers, but data remain limited. We analyzed 19 specimens of head and neck mucosal melanoma, assessing morphology and immunoprofile with melanocytic markers, including SOX10, S100, HMB-45, Melan-A, and the neuroendocrine markers synaptophysin, chromogranin, and INSM1. While 4 specimens exhibited synaptophysin positivity, none were positive for all 3 neuroendocrine markers, and only 1 specimen stained for INSM1. The absence of chromogranin suggests that synaptophysin expression may be aberrant rather than indicative of true neuroendocrine differentiation. As a result, the use of synaptophysin alone should be discouraged, and more specific markers such as chromogranin and INSM1 should be used in conjunction. A broad immunohistochemical panel and a high index of suspicion are essential to avoid misclassification of head and neck mucosal melanomas.

Only 43 patients with laryngeal melanosis have been reported to date. Concomitant malignancy and dysplasia of the upper aerodigestive tract, ranging from 26% to 50%, have been encountered with this condition. Given the above, we undertook this study to assess the burden of laryngeal melanosis diagnosed in a tertiary care center. This was a retrospective observational study done with a review of all patients with laryngeal biopsies received over the previous 5-year period (2017-2022), on encountering an index patient. A representative slide from each patient was stained with Masson Fontana and bleached with potassium permanganate, and immunohistochemistry was performed using S100 and HMB45 (PMEL), wherever feasible. Sixty-five patients with laryngeal biopsies reported were included in the study, and laryngeal melanosis was detected in 9 patients (14% prevalence) of the total laryngeal biopsies. Seven out of 9 patients were associated with neoplasm, 6 patients (67%) with concomitant squamous cell carcinoma, and 1 (11%) with moderate dysplasia. We add another 9 patients to the list of laryngeal melanosis, based on our extensive literature search, taking the total to 52. We observed instances where laryngeal melanosis co-occurred with malignancies of the upper aerodigestive tract. Identifying laryngeal melanosis during direct laryngoscopy can serve as a marker that encourages surgeons and pathologists to exercise prudence and ensure thorough investigation.

Predominantly, case reports and small case series of endometriosis involving the bladder have been published. This study aimed to provide a contemporary clinicopathologic analysis of a large cohort of patients at a major academic center in the United States. A search was made through our urologic pathology database and expert consults of the senior author for patients with bladder endometriosis from 2006 to 2024. Eighty-eight patients were included. The mean age was 37 years (range: 18-80 years). Presenting symptoms included pelvic pain, abnormal uterine bleeding, dysmenorrhea, infertility, hydronephrosis, hematuria, bladder mass, pelvic mass, or an incidental finding during workup for other diseases. The bladder serosa was the most common site of involvement: 72 (82%) patients, followed by muscularis propria: 12 (14%) patients; perivesical adipose tissue: 11 (13%) patients, and submucosa: 1 (<1%) patient. Although none had malignant transformation, a subset presented as mimickers of bladder neoplasia. Fifty-six (62%) patients had involvement of other organs/sites, most commonly the ovary: 22 (25%); large intestine: 20 (23%); uterine serosa: 18 (20%); cul-de-sac: 15 (17%); broad ligament: 6 (7%), and other pelvis/abdominal cavity sites. CD10 was utilized in 9 (10%) patients. The mean duration of follow-up was 40 months (range: 1-208 months). All patients were alive at follow-up, with 30 (34%) having residual or recurrent endometriosis requiring additional treatment. This is one of the largest clinicopathologic studies to date of bladder endometriosis, and it may present as a mimicker of benign or malignant bladder neoplasia and frequently involves other sites.

Malignant peripheral nerve sheath tumors (MPNST) are aggressive sarcomas arising from Schwann cells or neurofibromas, comprising ∼10% of soft tissue sarcomas. Found in 8% to 13% of neurofibromatosis type 1 patients, they typically show spindle cells expressing S100 and SOX10. Some display heterologous differentiation (bone, cartilage, vessels, or glands). When rhabdomyosarcomatous features are present, they are called malignant peripheral nerve heath tumor with heterologous rhabdomyoblastic differentiation (malignant triton tumors), which are more prone to recurrence, metastasis, and worse outcomes. Epithelial differentiation does not affect prognosis. Despite advances in understanding MPNST biology, many pathophysiological mechanisms remain unclear. This review highlights their histopathology, focusing on malignant triton tumor.

IntroductionIn the era of increasing prostate needle core biopsy (PNCB) burden with extended core and MRI-guided biopsies, recommendations are limited on how many histologic levels are needed to identify prostate cancer parameters. Many institutions, including ours, have utilized up to 6 levels. Our quality improvement study evaluates undetected prostate cancer parameters and cost/time savings when reducing to 3 levels.MethodsFifty-eight PNCB series (204 individual PNCB) with prostate cancer were identified from 74 consecutive series (614 individual PNCB). Six levels placed on 2 slides were reviewed. Detection of prostate cancer, secondary Gleason patterns, extraprostatic extension, perineural invasion, and atypical small acinar proliferation (ASAP) were compared between the original 6 levels and a simulated reduction to 3 levels using 3 methods: 1) 3-level spanning most of the tissue block, 2) 3-level spanning the superficial block, and 3) 3-level spanning the deep block. Laboratory costs and microtomy/embedding time data were analyzed to determine savings following change to a 3-level protocol.ResultsThe simulated 3-level method spanning most of the block identified all cancer foci and parameters originally detected with 6 levels, except one focus of ASAP (N = 13). Small cancer foci (< 1 mm) and associated parameters were occasionally undetected when only 3 superficial or deep levels were reviewed. Switching to a 3-level cutting protocol saved $9134 over 6 months and reduced microtomy/embedding time by 9.7 min per 12-part PNCB series.ConclusionAt our institution, evaluating 3 levels spanning most of the block conserves resources while adequately detecting prostate cancer parameters.

Epithelioid angiosarcoma of the bladder is an exceptionally rare and aggressive vascular malignancy, characterized by a poor prognosis due to its high propensity for invasion and metastasis. Due to its rarity, the diagnosis is often challenging and may be misinterpreted as other high-grade malignancies. Patients commonly present with advanced-stage disease, including muscle invasion at the time of diagnosis, leading to unfavorable clinical outcomes. We report a 73-year-old male patient with a history of metastatic colon cancer (to the cervical lymph node) who presented with gross hematuria. Imaging and cystoscopy evaluation revealed a mobile bladder mass with possible right anterior bladder wall thickening and necrotic tissue. Transurethral resection of the bladder tumor performed outside was initially interpreted as muscle-invasive poorly differentiated carcinoma with sarcomatoid differentiation. Upon reviewing the slides at our institution, the diagnosis was revised to epithelioid angiosarcoma of the bladder. Despite an aggressive multimodal therapeutic approach, including chemotherapy and radical prostatectomy, the patient's clinical condition progressively worsened, ultimately leading to mortality 11 months post-diagnosis. This case report highlights the diagnostic challenges and aggressive nature of epithelioid angiosarcoma of the bladder, emphasizing the need for early detection and exploration of novel therapeutic strategies to improve patient outcomes.