Extraneural Sclerosing Perineurioma of the Tongue

Abstract

Perineurioma (PN) is an uncommon benign peripheral nerve sheath tumor. For the rarity of this tumor in the oral cavity, otolaryngologists and oral surgeons might not be familiar with this entity. Perineuriomas are typically benign and complete excision is deemed adequate management. Thus, their histological recognition is mandatory to avoid unnecessary overtreatment. We report the clinicopathologic findings of an uncommon variant, the Extraneural Sclerosing PN, in an unusual and never described site, the tongue.

Practical Approach to Histological Diagnosis of Peripheral Nerve Sheath Tumors: An Update

“…Occasionally, some cases exhibiting ossification foci, granular cell change, and Pacinian-like bodies have been described [ 58 , 59 ]. Apart from the classic type, soft tissue perineurioma may exhibit in at least two different histological variants, reticular and sclerosing perineurioma [ 60 , 61 , 62 , 63 ]. The former is characteristically composed of slender spindled cells, usually set in a myxo-edematous stroma showing cytoplasmic anastomosing processes, resulting in a reticular or lace-like appearance [ 60 , 61 ].…”

“…Sclerosing perineurioma is an unusual variant, mainly occurring in young male adults and involving almost exclusively the superficial soft tissues of the hand. Histologically, it is composed of a proliferation of spindled to rounded/epithelioid cells with pale cytoplasm, indistinct cell borders, and slightly hyperchromatic nuclei arranged in corded, trabecular, or whorled growth patterns and set in an abundant fibro-sclerotic stroma ( Figure 19 ) [ 62 , 63 ]. Despite the morphological variant, perineurioma may exhibit potential alarming/atypical features in approximately 10–20% of cases, including degenerative nuclear atypia (pleomorphic and multinucleated cells with nuclear pseudoinclusions), mitotic activity, hypercellularity, and the infiltration of skeletal muscle.…”

“…Despite the morphological variant, perineurioma may exhibit potential alarming/atypical features in approximately 10–20% of cases, including degenerative nuclear atypia (pleomorphic and multinucleated cells with nuclear pseudoinclusions), mitotic activity, hypercellularity, and the infiltration of skeletal muscle. Notably, all patients with perineuriomas showing these atypical features have experienced a benign clinical course [ 63 ].…”