Variability of expression and arrangement of cytokeratin and neurofilaments in cutaneous neuroendocrine carcinomas (Merkel cell tumors): immunocytochemical and biochemical analysis of twelve cases.

TY - JOUR

T1 - Variability of expression and arrangement of cytokeratin and neurofilaments in cutaneous neuroendocrine carcinomas (Merkel cell tumors): immunocytochemical and biochemical analysis of twelve cases.

AU - Moll, R

AU - Osborn, M

AU - Hartschuh, W

AU - Moll, Ingrid

AU - Mahrle, G

AU - Weber, K

PY - 1986

Y1 - 1986

N2 - Twelve specimens of cutaneous neuroendocrine carcinomas (Merkel cell tumors) available as fresh tissue were analyzed for intermediate filament (IF) expression by immunocytochemical and biochemical methods. In immunofluorescence microscopy, most cases were positive for both simple-epithelium-type cytokeratins and the neurofilament L- and M-polypeptides. Several different IF staining patterns ranging from presence of plaque-like structures (fibrous bodies) only to nearly exclusive expression of delicate cytokeratin fibrils could be distinguished. In immunoelectron microscopy the labeling for both cytokeratin and neurofilament polypeptides seemed evenly distributed among the IFs of the fibrous bodies. In primary culture, tumor cells maintained the coexpression of both IF types. Desmoplakin-positive true desmosomes were found in 5 specimens. Biochemically, cytokeratins nos. 8, 18 and, variably, 19, as well as IT protein and, in many specimens, the neurofilament L-protein and a putative neurofilament M-protein were detected. Only traces of the neurofilament H-polypeptide were found. Our results show that a coexpression of cytokeratin IFs and neurofilaments in variable patterns is a characteristic feature of cutaneous neoendocrine carcinomas; occasionally, however, neurofilaments may be very scarce. The biological, histogenetic and diagnostic implications are discussed.

AB - Twelve specimens of cutaneous neuroendocrine carcinomas (Merkel cell tumors) available as fresh tissue were analyzed for intermediate filament (IF) expression by immunocytochemical and biochemical methods. In immunofluorescence microscopy, most cases were positive for both simple-epithelium-type cytokeratins and the neurofilament L- and M-polypeptides. Several different IF staining patterns ranging from presence of plaque-like structures (fibrous bodies) only to nearly exclusive expression of delicate cytokeratin fibrils could be distinguished. In immunoelectron microscopy the labeling for both cytokeratin and neurofilament polypeptides seemed evenly distributed among the IFs of the fibrous bodies. In primary culture, tumor cells maintained the coexpression of both IF types. Desmoplakin-positive true desmosomes were found in 5 specimens. Biochemically, cytokeratins nos. 8, 18 and, variably, 19, as well as IT protein and, in many specimens, the neurofilament L-protein and a putative neurofilament M-protein were detected. Only traces of the neurofilament H-polypeptide were found. Our results show that a coexpression of cytokeratin IFs and neurofilaments in variable patterns is a characteristic feature of cutaneous neoendocrine carcinomas; occasionally, however, neurofilaments may be very scarce. The biological, histogenetic and diagnostic implications are discussed.

M3 - SCORING: Zeitschriftenaufsatz

VL - 10

SP - 473

EP - 495

JO - ULTRASTRUCT PATHOL

JF - ULTRASTRUCT PATHOL

SN - 0191-3123

IS - 6

M1 - 6

ER -