Microcystic/reticular schwannoma of the lower leg: Case report with review of literature

Abstract

Introduction: Microcystic/reticular schwannoma is a distinctive histopathological variant of schwannoma, which is rare. Its occurrence in the subcutaneous soft tissue of the lower extremity has rarely been reported. Case Report: We report a microcystic/reticular schwannoma arising from a subcutaneous lesion on the lower leg of a 33-year-old man. The patient noticed a subcutaneous mass on the right lower leg six months before admission and experienced radiation pain in the left lower leg. Magnetic resonance imaging revealed a well-demarcated mass with 11-mm maximum diameter with low signal intensity on T1-weighted imaging and high signal intensity on T2-weighted imaging in the subcutaneous region of the right lower leg. Histological examination revealed a cellular area at the periphery of the tumor, although the majority of the tumor showed a microcystic/reticular structure within the myxo-collagenous stroma. The current case was well capsulated and did not show an infiltrative growth pattern. In addition, aggregation of foamy macrophages was frequently seen, although it was reported as a rare feature. After complete surgical excision with clean resection margins, the patient is well, with no evidence of tumor recurrence on follow-up after postoperative 14 months. Conclusion: In this case, infrequent findings for microcystic/reticular schwannoma were observed, although the presence of the classical Antoni A area was helpful for the diagnosis of microcystic/reticular schwannoma.