International Journal of Surgical Pathology最新文献

Intra-osseous hemangiomas are uncommon tumors that can present diagnostic and treatment dilemmas. Bone hemangiomas with papillary and glomeruloid growth patterns are exceptionally rare. We present an example of an intra-osseous hemangioma of the rib displaying aggressive features on both radiology and histology. Morphologically, prominent papillary and glomeruloid architectural patterns were observed, in addition to features of cavernous and capillary hemangiomas. Extensive extra-osseous soft tissue involvement was seen. Awareness of the diverse histological features and locally aggressive behavior of bone hemangiomas is important in avoiding over-interpretation as a malignant lesion.

Background: Primary uterine alveolar soft part sarcoma (ASPS) is a rare, indolent mesenchymal malignancy with less than 40 patients documented in the literature.

Case: We report an example of ASPS in a 61-year-old postmenopausal woman. Macroscopically, the uterus showed multiple nodular masses. Microscopic examination revealed tumor arranged in nests and alveolar pattern. The tumor cells were moderately to markedly pleomorphic, epithelioid to polygonal, with eccentrically placed nuclei, vesicular chromatin, prominent macro-nucleoli, and moderate to abundant eosinophilic cytoplasm. PAS-positive and diastase-resistant intracytoplasmic crystals were also seen in some tumor cells. On immunohistochemistry, the tumor cells showed diffuse positivity for vimentin and nuclear positivity for TFE3, a surrogate marker for ASPS. These were negative for SMA, desmin, CD10, h-caldesmon, cyclin D1, EMA, Melan A, and CD34. SMARCB1 expression was retained. Based on the histopathology and IHC, a final diagnosis of uterine ASPS was rendered.

Conclusions: Knowledge of the characteristic histopathologic and immunohistochemical features can help accurately diagnose such rare tumors. Knowledge of the characteristic histopathologic and immunohistochemical features can help accurately diagnose such rare sarcoma in an uncommon site with an unusual age.

We report a patient with isolated stromal lipofuscinosis of the seminal vesicle, a rare entity characterized by intracytoplasmic pigmented granules within stromal cells intimately surrounding seminal vesicle epithelium. Only 4 patients with this unusual phenomenon have been previously reported in the literature. Recognizing this incidental and presumably non-pathologic finding is important to prevent misclassification as a more concerning lesion.

Malignant mesothelioma of the tunica vaginalis is an extremely rare and aggressive tumor that is frequently encountered in elderly patients. The diagnosis of malignant mesothelioma of the tunica vaginalis poses a diagnostic challenge due to its infrequency and nonspecific clinical presentation. Histopathological examination and immunohistochemical staining are essential in differentiating this tumor from other para-testicular masses and establishing a definitive diagnosis. Early detection and comprehensive treatment planning are crucial for improving the prognosis and overall outcomes for patients with this rare malignancy. We present a report of malignant mesothelioma of the tunica vaginalis in a 78-year-old male patient with no history of asbestos exposure who presented with a large infiltrative left para-testicular mass. Histopathological examination revealed a biphasic proliferation composed of epithelioid and spindle cells with infiltrative features, foci of necrosis, and increased mitotic figures. Immunohistochemical staining exhibited positive staining for WT1, D2-40, and calretinin, supporting the mesothelial origin of the tumor. Notably, BerEP4 staining was negative, arguing against carcinoma. Immunostaining for keratin 5 was positive, supporting the mesothelial differentiation. The Ki67 proliferation index was high. The differential diagnosis included adenomatoid tumors, germ cell tumors, and pleomorphic sarcoma. We aim to discuss the clinical presentation, diagnostic approach, and therapeutic approaches of this rare entity.

Background. With <40 case reports published in the English literature, mucinous cystadenocarcinoma of the breast is quite rare compared to its counterparts in the ovary, pancreas, and appendix. The purpose of this case report is to enrich scientific data by sharing the clinicopathological features of this new and extremely rare entity and present possible difficulties encountered in the biopsy materials. Case Report. A 34-year-old female patient presented with the complaint of white discharge from her left nipple lasting 8 months. Physical and radiological examination of the patient revealed a mass in the lower quadrant of the left breast and tru-cut biopsy was performed. The diagnosis of invasive breast carcinoma of no special type was reported. After neoadjuvant chemotherapy, left subcutaneous mastectomy and left sentinel lymph node biopsy were performed. Microscopic evaluation of the mastectomy material revealed a tumor consisting of stratified columnar cells with basally located nuclei and intracytoplasmic mucin, showing papillary structures and tufting toward the lumen. Peripheral myoepithelial cells were not identified with p63 and calponin immunohistochemistry. The diagnosis of mucinous cystadenocarcinoma was given through histomorphological and immunohistochemical evaluations. Conclusion. Clarifying unknown points about this rare malignancy of the breast and understanding the tumor biology is possible through evaluation of case reports. For this purpose, our case of primary mucinous cystadenocarcinoma is presented and its clinicopathological features are briefly discussed.

Mechanistic target of rapamycin kinase (mTOR) is a member of the phosphatidylinositol-3-hydroxide kinase (PI3 K)-related protein kinase family that functions as a central regulator of cell growth, metabolism, proliferation, and survival. The role of the TSC-mTOR signaling pathway in kidney tumors has been implicated in some hamartoma syndromes; however, with the advent and wide utilization of molecular studies, a growing number of kidney tumors have been linked to somatic or germline mutations involving genes that encode for this pathway, including eosinophilic solid and cystic renal cell carcinoma, low-grade oncocytic tumor, eosinophilic vacuolated tumor, renal cell carcinoma with fibromyomatous stroma and angiomyolipoma, among others. Herein, we review the contemporary developments of mTOR pathway-related renal neoplasia, focusing on the clinicopathologic features of the tumor entities.

Objectives: This study aimed to investigate the histological characteristics and treatment efficacy of non-immunoglobulin G4-related fibrosing mediastinitis and discuss differential diagnoses for this rare entity.

Methods: We present a case study of non-immunoglobulin G4-related fibrosing mediastinitis diagnosed on core biopsy and treated with steroids. A total of four 18-gauge core needle biopsy specimens were obtained for surgical pathology. Analysis of the patient's medical history, radiological characteristics of fibrosing mediastinitis, histological features, immunohistochemistry results, the differential diagnosis and treatment efficacy of different types of fibrosing mediastinitis was performed.

Results: This report describes a unique presentation of fibrosing mediastinitis (syncope and weight loss) that was concerning for malignancy. Histological, laboratory and radiographical studies confirmed the diagnosis of non-immunoglobulin G4-related fibrosing mediastinitis. The patient received corticosteroid treatment which showed marked improvement after 1 month of treatment.

Conclusions: Fibrosing mediastinitis is an extremely uncommon entity with unknown pathogenesis, and it is more important to rule out malignancy and infection than to delineate between fibrosing mediastinitis and IgG4-related disease. In doing this, we may reasonably initiate a trial of corticosteroids which may prove beneficial, as in this patient. More studies on the pathogenesis of fibrosing mediastinitis are necessary to guide better directed treatments.

Loss of histone H3K27 Trimethylation (H3K27me3) immunohistochemical expression is commonly used as an ancillary test and a surrogate marker for the diagnosis of malignant peripheral nerve sheath tumor (MPNST). A potential histological mimic of MPNST is sarcomatoid carcinoma. Prompted by an index specimen of sarcomatoid carcinoma with H3K27me3 loss and the lack of literature on such phenomenon, we sought to determine the frequency of H3K27me3 loss of expression in a cohort of sarcomatoid carcinomas. Fifty specimens of primary and metastatic sarcomatoid carcinomas with spindle cell morphology mimicking MPNST were prospectively and retrospectively retrieved from our institutional archives and stained with an antibody to H3K27me3. H3K27me3 staining was lost in 4 of the 50 specimens (8%). These specimens included a primary sarcomatoid urothelial carcinoma of the bladder resection, two local recurrences (sarcomatoid squamous cell carcinoma of the larynx and oral cavity) as well as a metastatic sarcomatoid renal cell carcinoma. Next-generation sequencing performed on all four specimens demonstrated gene mutations and copy number alterations with TP53, FANC (FANCD2 and FANCI), and TERT being the most common gene mutations and CDKN2A/B copy number loss and 11q region amplification being the most common copy number gene alterations. Mutations involving NF1, SUZ12, or EED were absent in all tested specimens. In conclusion, H3K27me3 expression may be lost in as many as 8% of sarcomatoid carcinomas which can pose as a potential diagnostic pitfall, especially in challenging sarcomatoid carcinoma specimens with absent keratin staining.

The RAS-RAF-MEK-ERK signaling cascade is the most frequently affected signaling pathway in colorectal cancer. BRAFV600E mutations serve as a drug-treatable hotspot and KRAS mutations as a predictor of susceptibility to anti-epidermal growth factor receptor therapy. Concomitant non-V600E BRAF and KRAS mutations may coexist and are rarely reported in the literature. We report a patient of colorectal carcinoma with inguinal lymph node metastases harboring mutations at the KRAS and BRAF non-V600E mutation codon detected by next-generation sequencing with an emphasis on clinical, pathological, and therapeutic implications of the mutation and review of the literature.