Malignant peripheral nerve sheath tumor MPNST

FIGURE 4.17 CD57 in malignant peripheral nerve sheath tumor (MPNST). Reactivity for S-100 protein, CD57, myelin basic protein, or collagen type IV is observed in greater than 85% of MPNSTs. 

Malignant peripheral nerve sheath tumor (MPNST) may likewise assume a pleomorphic appearance. In most instances, that tumor variant shows patterns of reactivity for S-100 protein, CD56, CD57, and collagen type IV that are superimposable with those of better differentiated (spindle cell) MPNSTs." In the absence of focal S-100 protein expression and foci with conventional appearances, it is very difficult (if not impossible) to render this diagnosis with certainty. Unlike spindle cell variants of MPNST, pleomorphic subtypes have not been shown to be desmin-reactive. 

Hirose T, Scheithauer BW, Sano T. Perineurial malignant peripheral nerve sheath tumor (MPNST) A clinicopathologic, immunohistochemical, and ultrastructural study of seven cases. Am J Surg Pathol. 1998 22 1368-1378. 

In addition, mice carrying hnked germline mutations in Nfl and p53 develop malignant peripheral nerve sheath tumors (MPNSTs), which supports a cooperative and causal role for p53 mutations in MPNST development. 

KER, keratin, detected by a mixture of GAMS.2, MAK-6, and AEl /AE3 EMA, epithelial membrane antigen VIM, vimentin DES, desmin MSA, muscle-specific actin SMA, smooth muscle (alpha isoform) actin GALD, h-caldesmon S-IOOP, S-100 protein OCN, osteocalcin LM, laminin UL, Ulex europaeus I lectin binding FS, fibrosarcoma SGRMS, spindle cell rhabdomyosarcoma LMS, leiomyosarcoma MPNST, malignant peripheral nerve sheath tumor MSS, monophasic spindle cell synovial sarcoma SCAS, spindle cell angiosarcoma KS, Kaposi s sarcoma FOS, fibroblastic osteosarcoma. 

GFAP, glial fibrillary acidic protein MPNST, malignant peripheral nerve sheath tumor. 

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