International Journal of Surgical Pathology最新文献

Low-grade fibromatosis-like metaplastic breast carcinoma is a rare and challenging subtype of breast carcinoma due to its distinctive histological features mimicking a variety of lesions varying from benign to malignant, underscoring the importance of accurate diagnosis. We evaluated the clinicoradiological, histopathological features, and immunohistochemical profile of 11 low-grade fibromatosis-like metaplastic breast carcinoma patients diagnosed at our tertiary care center. Median age at diagnosis was 67 years (range 47-76 years) with a palpable breast lump of 1 to 2 years duration. Histologically, besides classical fibromatosis-like pattern, nodular growth was also noted (n = 2). Cytologically, spindle cell and stellate morphology were observed in 3 tumors each while rest of the tumors showed both features. Cellularity was minimal in 2, moderate in 8 and high in 1 tumor with mild to moderate nuclear atypia. Two tumors had small foci of infiltrative epithelial nests. Mixed inflammatory infiltrate was seen in all tumors. On immunohistochemistry, the tumor cells demonstrated positive staining for AE1/AE3, keratin 5/6, SMA, and p63, while negative for other markers. Details of initial treatment were available in 9 patients, of which 3 developed metastases. Low-grade fibromatosis-like metaplastic breast carcinoma is a rare and distinct subtype of metaplastic breast cancer with unique histological features and heterogeneity in morphology, posing diagnostic challenges and should be diagnosed after meticulous clinicopathological evaluation, comprehensive sampling and extensive immunohistochemistry panel.

Appendicitis is a common surgical emergency characterized by inflammation of the appendix, often attributed to luminal obstruction or bacterial infection. However, rare etiologies, such as parasitic infections, can also lead to appendicitis. Among these, Entamoeba histolytica, a protozoan parasite causing amoebiasis, is an infrequent but noteworthy cause. Amoebic infection of the appendix occurs when trophozoites invade the mucosal layer of the appendix, leading to inflammation, tissue necrosis, and, in severe disease, perforation. Amoebic appendicitis is more common in regions where amoebiasis is endemic, such as tropical and subtropical areas, and is often associated with poor sanitation and contaminated water supplies. The clinical presentation of amoebic appendicitis often mimics acute bacterial appendicitis, including abdominal pain, fever, and leukocytosis, making it challenging to diagnose preoperatively. The condition may coexist with colonic amoebiasis or present independently. The severity of amoebic appendicitis may be much more than that of bacterial appendicitis, and it may require more intensive management, hence the importance of knowing the diagnosis. Histopathological examination and identification of E histolytica in the appendix are crucial for a definitive diagnosis. Prompt surgical intervention, along with anti-amoebic therapy, is essential for successful management. This case report highlights an uncommon etiology of appendicitis due to amoebic infection, emphasizing the need for clinicians to consider parasitic etiologies in regions where amoebiasis is prevalent.

Cellular spindled histiocytic pseudotumor is a rare benign lesion composed of spindle-shaped histiocytes that may mimic malignant tumors, especially in extranodal sites such as the breast. We report a 56-year-old female patient presenting with a painful, palpable mass in the left breast accompanied by nipple discharge and skin changes. The patient had a history of previous benign excisional biopsies in the same region. Histopathological evaluation of a core needle biopsy revealed spindle-shaped histiocytic cells with mild nuclear atypia, and associated fat necrosis. Immunohistochemical analysis confirmed histiocytic differentiation (CD163, CD68, CD31 positive) and excluded epithelial, melanocytic, and stromal malignancies. These findings supported a diagnosis of cellular spindled histiocytic pseudotumor. Cellular spindled histiocytic pseudotumor of the breast is a rare and potentially misleading lesion that may clinically and radiologically mimic malignancy. Awareness of its histologic and immunophenotypic features is critical to avoid misdiagnosis and overtreatment. Accurate recognition may prevent unnecessary radical surgical or oncologic interventions.

A 38-year-old woman presented with a visible conjunctival mass in the right eye. Anterior segment examination revealed a red, painless, and elevated lesion on the temporal bulbar conjunctiva in the right eye. Anterior segment swept-source optical coherence tomography (AS SS-OCT) showed a subepithelial hyperreflective mass with a hyporeflective transition zone separating the lesion from the underlying tissues. In vivo confocal microscopy (IVCM) demonstrated scattered and disorganized hyperreflective collagen fibers in the lymphoid stromal layer and dense meshwork of collagen fibers, dilated vessels, and Langerhans cells in the fibrous stromal layer. After excisional biopsy of the lesion, histopathological examination revealed that the lesion consisted of spindle cells with occasional nuclear pseudoinclusions in a background of scattered collagen fibers, with no atypia and mitosis. Spindle cells showed diffuse staining for vimentin and CD34 and no staining for S-100, EMA, and SMA. Some spindle cells stained positive for factor XIIIa. Few KIT positive mast cells and CD68 positive histiocytes were also observed. Ki-67 proliferation index was 2% to 3%. These findings were consistent with the diagnosis of conjunctival stromal tumor (COST). This case report highlights the AS SS-OCT and IVCM findings in a rare example of COST. Histopathology and immunohistochemistry findings still remain the gold standard for diagnosis.

Giant cell tumor of soft tissue is a low-malignant behavior neoplasm, with histopathological features and immunophenotype similar to its bone counterpart. Primary giant cell tumor of soft tissue in the biliary tract is an exceedingly rare entity. Here, we describe the first patient of giant cell tumor of soft tissue involving the common hepatic duct in a 66-year-old man who developed a biliary obstruction. Imaging revealed an ill-defined 34 × 21 mm intraluminal mass at the liver hilum, initially suggestive of a Klatskin tumor. A right hepatectomy with excision of the common hepatic duct and gallbladder was performed, followed by a Roux-en-Y cholangiojejunostomy. Histological examination revealed that the entire tumor was not associated with any other form of carcinoma but was morphologically similar to giant cell tumors of soft tissue. The lesion consisted of 2 distinct cell populations: mononuclear cells and multinucleated osteoclast-like giant cells. The mononuclear cells displayed no atypical features, and their nuclear characteristics were similar to those observed in the multinucleated giant cells. Tumor cells were negative for keratin AE1/AE3, keratin 7, keratin 19, and keratin 20, but positive for CD68. The patient remained well, without local recurrence or metastasis during 6 years of follow-up. The present tumor highlights the rarity of the location, and the diagnostic challenges encountered prior to surgery.

Inflammatory rhabdomyoblastic tumor (IRMT) is a newly recognized type of intermediate/borderline rhabdomyogenic tumor. It most commonly occurs in the lower extremities and trunk muscles of young and middle-aged men, characterized by slow growth, clear boundaries, a fibrous capsule containing a large number of peripheral lymphocyte aggregations, morphological spindle to epithelioid cells, and dense histiocytic infiltration. It exhibits an immunohistochemical profile consistent with a primitive skeletal muscle phenotype and a near-haploid karyotype genetically, with most behaving indolently. As malignant neoplasms of skeletal muscle differentiation are more common than benign ones, IRMT cannot yet be classified into the existing subtypes of neoplasms of skeletal muscle differentiation, making it prone to misdiagnosis as other pleomorphic tumors, including being overdiagnosed as high-grade sarcomas. We present a case report of IRMT initially diagnosed as rhabdomyosarcoma based on a core needle biopsy specimen, which was overdiagnosed. Additionally, we review the literature to explore the clinicopathological features of this tumor, aiming to enhance understanding of this type of tumor.

Background and AimImmunohistochemistry (IHC) and/or polymerase chain reaction (PCR) are essential for confirming active cytomegalovirus (CMV) infection in patients with inflammatory bowel disease (IBD). A definitive cut-off has not yet been established; however, Roblin et al suggested a viral load threshold of > 250 viral copies/mg of tissue. In this study, we examined the concordance between IHC and quantitative real-time PCR (qPCR) in the detection of CMV in colonic biopsy specimens.MethodsA total of 170 samples that underwent IHC and qPCR were collected. The positive rate and concordance of IHC and qPCR were studied, and the impact of ulcer tissue on both detection methods was observed.ResultsIn a study of 170 hematoxylin-eosin (H&E) sections, 8 samples were found to be infected with cytomegalovirus. The positive rates of CMV detection using IHC and qPCR were 17% (29/170) and 25% (43/170), respectively. Among the IHC-positive samples, the qPCR positive rate was 100% (29/29), with all CMV-DNA loads > 250 copies/mg. The concordance between IHC and qPCR was 94% (kappa = 0.756, P < .001). IHC analysis revealed that positive cells in ulcerated mucosa were more frequent than those in nonulcerated mucosa (P < .001). Additionally, a total of 14 samples tested negative for CMV via IHC but positive through qPCR. Among these, 11 samples did not contain ulcerated tissue.ConclusionThe presence of one or more IHC-positive cells in colon biopsy samples indicates a high CMV-DNA load in qPCR (> 250 copies/mg). IHC-positive cells were more frequently observed in ulcerated mucosa compared to nonulcerated mucosa.

Polythelia refers to the presence of additional nipples typically located along the "milk line." While its atavistic nature and associations with congenital anomalies are well documented, its clinicopathological features are less defined. This retrospective study reviewed 131 lesions diagnosed as polythelia in 112 patients from 1999 to 2024. The median age of patients at the time of excision was 28 years (range: 6 months to 72 years). Most (101, 90.2%) patients were female. Lesions were located around the breast (42%), chest (28%), axilla (15%), inframammary fold (8%), and abdomen (6%). Histopathology of 107 lesions showed breast glandular tissue in 83 (77.6%). Sixty (72.3%) of these also exhibited nipple-type smooth muscle, and 24 (22.4%) contained smooth muscle only. Among lesions with glandular tissue, 66/83 (79.5%) had ducts, and 17/83 (20.5%) exhibited lobules. In addition, 54 lesions, initially misdiagnosed as accessory nipples, were reclassified as "clinical pseudo-polythelia." The latter included nevi (48.1%), seborrheic keratosis (13.0%), and hemangiomas (3.7%). Based on our study, polythelia (when encountered in routine practice) is typically a benign and solitary lesion, excised for cosmetic reasons in younger females. Although one lesion of ductal carcinoma in situ in polymastia, under a polythelia, was encountered, no tumor with any nipple or breast lesion was identified in polythelia per se. No other congenital diseases or medical condition was identified in our cohort; however, there were ipsilateral or contralateral malignancies in the native breast in 7.6% of the lesions. Recognition of polythelia is essential to distinguish it from other skin lesions.

Crystal-storing histiocytosis is a rare condition characterized by the accumulation of crystalline immunoglobulins within histiocytes, often associated with plasma cell disorders such as multiple myeloma. We report a 70-year-old man with a history of IgG-lambda multiple myeloma, systemic amyloidosis, and end-stage renal disease managed with peritoneal dialysis and long-term lanthanum carbonate therapy for hyperphosphatemia, who presented with gastrointestinal bleeding. Endoscopy revealed nodular erythematous mucosa in the duodenum, and biopsies showed histiocytosis in the lamina propria. The histiocytes showed abundant cytoplasm containing periodic acid-Schiff-positive diastase-resistant intracellular material. Immunohistochemical staining revealed diffuse CD68 positivity and lambda light-chain restriction of the storage material in the histiocytes, supporting a diagnosis of crystal-storing histiocytosis. Differential diagnoses, including Whipple disease, mycobacterial infections, lanthanum deposition, amyloidosis, and xanthoma, were excluded based on histological findings and clinical history. This report highlights the importance of recognizing crystal-storing histiocytosis in uncommon sites such as the duodenum, especially in the context of plasma cell dyscrasias.

Whipple disease is a rare systemic disease caused by Tropheryma whipplei. It can present with a wide range of nonspecific symptoms that might overlap with underlying medical conditions, posing a diagnostic challenge. We present a 61-year-old man with a past medical history of rheumatoid arthritis and chronic inflammatory demyelinating polyneuropathy, who presented with persistent leukocytosis and supraclavicular lymphadenopathy. A positron emission tomography scan revealed hypermetabolic activity in the supraclavicular, abdominal, and pelvic lymph nodes along with a myocardial hypermetabolic lesion, concerning a lymphoproliferative disorder versus sarcoidosis. A supraclavicular lymph node excisional biopsy revealed complete architectural effacement by a diffuse foamy histiocytic infiltrate without granuloma formation or necrosis. The differential diagnosis included underlying infection, histiocytic neoplasm, lymphoproliferative disorder, storage disorder, and others. Immunostains show the histiocytic cells were positive for CD68 and CD163, while negative for S100, CD1a, kappa, lambda, and BRAF V600E. Grocott-Gömöri's methenamine silver and periodic acid-Schiff (PAS) stains demonstrated diffuse intracytoplasmic granular staining that was resistant to diastase treatment. Gram, acid fast bacilli, and Fite stains were negative. Electron microscopy revealed rod-shaped organisms with a trilaminar plasma membrane, morphologically consistent with T whipplei. Polymerase chain reaction was positive for T whipplei, confirming the diagnosis. Although rare, Whipple disease should be considered in immunocompromised patients presenting with nonspecific nongastrointestinal symptoms and lymphadenopathy clinically simulating lymphoma. Periodic acid-Schiff D-positive inclusions, along with confirmatory molecular results, are crucial for diagnosis. Whipple disease is a curable disease that can be lethal if unrecognized, emphasizing the importance of heightened awareness for early diagnosis and timely treatment.