plexiform MPNST
Plexiform malignant peripheral nerve sheath tumor (plexiform MPNST) is an atypical cellular peripheral nerve sheath tumor of infancy and childhood.
Synopsis
localization: lower extremities, upper extremities, orbital region
size: from 1.5 to 8 cm in size (median, 3 cm)
possibly neonatal (congenital)
Predisposition: von Recklinghausen disease (NF1)
frequent local recurrence
predominantly superficial location within the dermis and subcutis, with occasional extension into deeper soft tissues
infiltrative or sharply demarcated margins
appearance of entangled or intertwined hypercellular nerve trunks, resulting in a plexiform appearance at low magnification
oval to serpentine nuclei with vesicular chromatin pattern
small basophilic nucleoli
mitoses (1 to 18/10 high-power fields)
no necrosis nor vascular invasion
Differential diagnosis
plexiform schwannoma or cellular schwannoma
- nuclear pleomorphism
- Antoni B areas
- thick-walled hyalinized blood vessels
- secondary degenerative features
plexiform neurofibroma
hamartomatous lesions of childhood
classical MPNST
Progonis
frequent local recurrence
complete excision should be ensured to prevent local recurrences and potential metastases.
References
Meis-Kindblom JM, Enzinger FM. Plexiform malignant peripheral nerve sheath tumor of infancy and childhood. Am J Surg Pathol. 1994 May;18(5):479-85. PMID: #7513502#