Perineurial cell tumor (perineurioma) with granular cells.
A form of benign cutaneous tumor with perineurioma findings and with the presence of associated granular cells is described. The two cases studied consisted of whorls made up of a high number of circumferentially arranged flattened cells, with perineurial characteristics, including bipolar cell processes, pinocytotic vesicles, a basal lamina, a positive immunoreactivity for EMA, and absence of immunostaining for S-100 protein. The granular cells, enclosed within the whorls, contained densely packed vesicles, particles with an apparently solid core, as well as membrane-limited vacuoles with disintegrating cellular organelles and electron-dense amorphous material. While failing to demonstrate any immunoreactivity for EMA, the granular cells showed positivity for S-100 protein, which supports their Schwann-cell origin. Due to its morphological and immunohistochemical characteristics, this peculiar form of tumor can be considered as a perineurioma with perineurial cell whorls and granular cell changes occurring in associated Schwann cells at the center of the whorls.
Díaz-Flores
L
L
Department of Anatomy and Pathology, Faculty of Medicine, University of La Laguna, Santa Cruz de Tenerife, Islas Canarias, Spain.
Alvarez-Argüelles
H
H
Madrid
J F
JF
Varela
H
H
Gonzalez
M P
MP
Gutierrez
R
R
D000328:Adult; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008854:Microscopy, Electron; D018396:Mucin-1 / Q000032:analysis; D018317:Nerve Sheath Neoplasms / Q000737:chemistry / Q000175:diagnosis / Q000473:pathology*; D010525:Peripheral Nerves / Q000737:chemistry / Q000473:pathology* / Q000648:ultrastructure; D010524:Peripheral Nervous System Neoplasms / Q000737:chemistry / Q000175:diagnosis / Q000473:pathology*; D009418:S100 Proteins / Q000032:analysis
D018396:Mucin-1; D009418:S100 Proteins