Metaplastic breast carcinoma is very rare, and metaplastic carcinoma with chondroid differentiation is even rarer. Here, we report a case of metaplastic carcinoma with extensive chondroid differentiation mimicking chondrosarcoma that was challenging to diagnose. The tumor was characterized by an abundant chondromyxoid matrix. The definitive area of classic invasive ductal carcinoma was minimal. The peripheral portion of the tumor showed increased cellularity with pleomorphism and definitive invasive growth. Tumor cells in the chondrosarcomatous areas were diffusely immunoreactive for S-100 protein, patchy positive for cytokeratin, but negative for epithelial membrane antigen (EMA). Tumor cells in carcinomatous areas were diffusely positive for cytokeratin, S-100 protein, and patchy positive for EMA. In both areas, tumor cells were negative for smooth muscle actin (SMA) and CD34, while oncoprotein p53 was overexpressed. When pathologists encounter breast tumors with chondroid differentiation, careful sampling and immunohistochemistry for cytokeratin and SMA are most helpful to differentiate metaplastic carcinoma from malignant phyllodes tumor and malignant adenomyoepithelioma.
S100 Proteins/chemistry ; Neoplasm Metastasis ; Muscle, Smooth/pathology ; Middle Aged ; Metaplasia ; Keratins/metabolism ; Immunohistochemistry ; Humans ; Female ; Cell Differentiation ; Carcinoma/*complications/metabolism/pathology ; CA-15-3 Antigen/metabolism ; Breast Neoplasms/complications/metabolism/*pathology ; Antigens, CD34/biosynthesis ; Actins/metabolism

Osteoclast-like giant cell tumor of the pancreas is a very rare neoplasm, of which the histiogenesis remains controversial. A 63-yr-old woman was hospitalized for evaluation of epigastric pain. An abdominal computerized tomography revealed the presence of a large cystic mass, arising from the tail of pancreas. A distal pancreatectomy with splenectomy was performed. Histologically, the tumor was composed of mononuclear stromal cells intermingled with osteclast-like giant cells. In addition, there was a small area of moderately to well differentiated ductal adenocarcinoma. The final pathologic diagnosis was osteoclast-like giant cell tumor of the pancreas with ductal adenocarcinoma. Here, we describe the histopathological, immunohistochemical, ultrastructural and molecular biological findings of this tumor with review of the literature pertaining to this condition.
Antigens, CD/analysis ; Antigens, Differentiation, Myelomonocytic/analysis ; CA-15-3 Antigen/analysis ; Carcinoma, Pancreatic Ductal/metabolism/*pathology/ultrastructure ; Diagnosis, Differential ; Female ; Giant Cell Tumors/metabolism/*pathology/ultrastructure ; Humans ; Immunohistochemistry ; Keratin/analysis ; Microscopy, Electron ; Middle Aged ; Osteoclasts/*pathology ; Pancreatic Neoplasms/metabolism/*pathology/ultrastructure ; Proliferating Cell Nuclear Antigen/analysis ; Vimentin/analysis

We report a rare case of giant vascular eccrine spiradenoma (GVES) which developed in 56-yr-old Korean woman. It is a rare variant of eccrine spiradenoma (ES), which might be mistaken for angiomatous lesions in view of its florid vascularity and hemorrhagic features. Histogenesis of GVES is not clearly elucidated although it is known that ES presumably originates in the eccrine glands. To clarify the histogenesis of GVES, immunohistochemical stainings using various monoclonal antibodies were also performed. The tumor was composed of three types of cells, namely pale epithelial cells, small basal cells, and myoepithelial cells. Therefore, we conclude that GVES originated from eccrine gland and mainly differentiates toward secretory portion of secretory coil.
Actins/analysis ; Adenoma, Sweat Gland/blood supply/metabolism/*pathology ; Biological Markers/analysis ; CA-15-3 Antigen/analysis ; Eccrine Glands/blood supply/chemistry/*pathology ; Female ; Humans ; Immunohistochemistry ; Keratin/analysis ; Korea ; Membrane Proteins/analysis ; Middle Aged ; Muscle, Smooth/chemistry ; Sweat Gland Neoplasms/blood supply/metabolism/*pathology