Epithelial differentiation in medulloblastoma: comparison with other embryonal tumors of neuroectodermal origin.
Three cases of medulloblastoma characterized by epithelial differentiation are described in patients 6-months-, 1-month- and 8-years-old. Histologically, tumors from the two infant patients showed a perivascular arrangement without apparent radiated cytoplasmic processes from the vessels. Tumor cells displayed round and/or pleomorphic vesicular nuclei and a more abundant eosinophilic cytoplasm than that found in classic medulloblastoma. Neither Homer-Wright rosettes nor ependymal or ependymoblastic rosettes were noted in these tumors. The tumor in the 8-year-old patient exhibited a classic medulloblastoma component intermingled with abundant eosinophilic cytoplasm forming a tubular structure. Immunohistochemically, tumor cells in all cases were positive for cytokeratin, synaptophysin, and vimentin. In the third case involving the 8-year-old patient, epithelial tumor cells were positive for cytokeratin, whereas classic medulloblastoma components were negative for cytokeratin. Positive staining for melanoma-specific antigen was seen only in the third case, where strong reactivity of tumor cells formed a tubulus. However, the classic medulloblastoma component was negative for melanoma-specific antigen. Ultrastructurally, basal laminae were observed around tumor cells in the 6-month-old patient. These morphological and immunohistochemical features suggest that medulloblastoma with epithelial differentiation is a rare but distinct variant of medulloblastoma, and that some of these tumors should show differentiation in ocular pigment epithelium.
Sugita
Yasuo
Y
Department of Pathology and Biodefense, Saga Medical School, Saga, Japan. sugitaoy@post.saga-med.ac.jp
Tokunaga
Osamu
O
Terasaki
Mizuhiko
M
Morimatsu
Minoru
M
Shigemori
Minoru
M
D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor / Q000032:analysis; D002471:Cell Transformation, Neoplastic / Q000473:pathology*; D002528:Cerebellar Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000628:therapy; D002648:Child; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D004847:Epithelial Cells / Q000473:pathology*; D017809:Fatal Outcome; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging; D008297:Male; D008527:Medulloblastoma / Q000737:chemistry / Q000473:pathology* / Q000628:therapy; D058950:Melanoma-Specific Antigens; D009363:Neoplasm Proteins / Q000032:analysis; D009364:Neoplasm Recurrence, Local
D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D058950:Melanoma-Specific Antigens; D009363:Neoplasm Proteins