Soft-tissue perineurioma in a 20-year-old patient with neurofibromatosis type 1 (NF1): report of a case and review of the literature.
BACKGROUND
Perineurioma is a rare benign soft-tissue tumor composed of cells showing differentiation toward the perineurial cells of the nerve sheath. Although mutations in the neurofibromatosis 2 (NF2) gene have been documented in this tumor, there is no known association between perineuriomas and type 1 or 2 NF.


METHODS
This is the first report of a case of soft-tissue perineurioma occurring in a patient with NF1.


RESULTS
Histopathologic examination revealed a 2.0-cm well-circumscribed, spindle-cell neoplasm with slender, elongated, bipolar, wavy cytoplasmic processes and wavy, elongated nuclei in a hyalinized stroma with focal myxoid areas. The architecture was composed predominantly of short fascicles with areas exhibiting a storiform pattern. Immunohistochemistry showed positive labeling for epithelial membrane antigen (EMA) but no staining for S-100 and smooth muscle actin (SMA).


CONCLUSIONS
This case illustrates that perineurioma can occur in association with NF1. Perineuriomas can be confused with other spindle-cell neoplasms, and relevant features and immunohistochemistry of these lesions are outlined. The patient has not had a recurrence with limited follow-up.
Ausmus
Gregory G
GG
Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, USA.
Piliang
Melissa P
MP
Bergfeld
Wilma F
WF
Goldblum
John R
JR
D000328:Adult; D014408:Biomarkers, Tumor / Q000378:metabolism; D005260:Female; D006801:Humans; D018396:Mucin-1 / Q000378:metabolism; D018317:Nerve Sheath Neoplasms / Q000150:complications / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D009456:Neurofibromatosis 1 / Q000150:complications / Q000378:metabolism / Q000473:pathology*; D012983:Soft Tissue Neoplasms / Q000150:complications / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D013909:Thorax; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
D014408:Biomarkers, Tumor; D018396:Mucin-1