Follicular dendritic cells (FDC) are non-lymphoid, non-phagocytic accessory cells in the immune system that are essential for antigen presentation and germinal center reaction regulation. These cells are CD21+, CD35+, CD1a- and S100 protein +/- and they show desmosomes ultrastructurally. The most commonly involved sites by FDC tumors are lymph nodes but may arise at a variety of extranodal site...

Clear cell chondrosarcoma may be difficult to distinguish from metastatic clear cell renal carcinoma. Clear cell chondrosarcoma is strongly positive for 5100 and negative for epithelial markers. Clear cell carcinoma is cytokeratin positive and may also be positive with SiQO. S100 may also be useful in confirming grade 3 chondrosarcoma and mesenchymal chondrosarcoma. SiQO may assist in distingui...

BACKGROUND Although renal cell carcinoma (RCC) is considered to be an immunogenic tumor, the role of immunogenicity in this tumor for predicting treatment response has been little investigated. PATIENTS AND METHODS Resected RCC specimens from 25 patients who received cytokine treatment for metastases were investigated using immunohistochemistry for CD83+ or S100+ dendritic cells (DCs), CD8+ T...

A 24-year-old woman presented with a 5-month history of a left flank mass that was painful on palpation. Magnetic resonance imaging revealed a 10.0 × 6.0 × 2.5 cm mass consistent with lipoma. A fatty lobulated mass was excised and subjected to H&E staining and immunohistochemical analyses. The specimen consisted of mature univacuolated adipocytic cells, with intermixed multivacuolated eosinophi...

Astrocytoma as one of the most common central nervous system (CNS) tumors is rarely reported in veterinary literature. A 7-year-old Persian Lori-Bakhtiari ewe was presented to the clinic with a two months history of progressive blindness, nystagmus to the right, bilaterally decreased pupillary reflexes, head pressing and paddling. At necropsy, a whitish well-circumscribed mass with dimensions o...

Leiomyosarcoma of the stomach is a very rare malignancy that was not distinguished from the more frequent gastrointestinal stromal tumors until early 2000s. Here we report on a case of a metastatic disease that developed in a 47-year-old man 2 years after he was diagnosed with the primary tumor and treated with curative surgical excision and adjuvant doxorubicin. The primary and metastatic lesi...

Skin biopsy may be helpful in the diagnosis of H syndrome. A triad of dermal fibrosis, lymphocytic aggregates, and numerous CD68+, CD163+, S100-positive, and CD1a-negative dermal histiocytes is characteristic.

S100P, an EF-hand calcium-binding protein, has been reported to be associated with the progression of many types of cancers. Transfection of an expression vector for S100P into a benign, nonmetastatic rat mammary cell line causes a 4- to 6-fold increase in its level in all four transformant cell clones. When the resultant transformant cell lines are introduced in turn into the mammary fat pads ...

Patient: Female, 33 Final Diagnosis: Matrix-producing metaplastic breast carcinoma Symptoms: - Medication: - Clinical Procedure: Operative Specialty: Oncology Objective: Rare disease. BACKGROUND Metaplastic breast carcinomas are ductal carcinomas that undergo metaplasia into non-glandular growth patterns. They ...