Reticular perineurioma

Reticular perineurioma is an extremely rare benign peripheral nerve sheath tumor classified under soft tissue neoplasms (ICD-10: D36.1). It is a histological variant of perineurioma, a tumor composed of neoplastic perineurial cells — the specialized cells that normally form the perineurium, the protective sheath surrounding nerve fascicles. The reticular variant is distinguished by its characteristic reticular (net-like) or lace-like growth pattern on microscopic examination, with tumor cells forming interconnecting cords and strands within a myxoid or collagenous stroma. These tumors typically present as painless, slow-growing subcutaneous or deep soft tissue masses, most commonly affecting the extremities or trunk. Reticular perineurioma is generally considered a benign neoplasm with very low risk of recurrence or malignant transformation. Immunohistochemically, the tumor cells characteristically express epithelial membrane antigen (EMA) and claudin-1, markers consistent with perineurial differentiation, while being negative for S-100 protein, which helps distinguish them from schwannomas and neurofibromas. Diagnosis requires careful histopathological and immunohistochemical evaluation by an experienced pathologist, as the reticular growth pattern can mimic other soft tissue tumors. The primary treatment for reticular perineurioma is complete surgical excision, which is generally curative. No adjuvant chemotherapy or radiation therapy is typically required. Due to the rarity of this tumor, there are no established clinical guidelines, and management is largely based on case reports and small case series in the literature. Long-term prognosis is excellent following complete resection, though clinical follow-up may be recommended to monitor for local recurrence.

Common questions about Reticular perineurioma