Pair of glomus tumors in thigh – both periosteal and intramuscular: Rare tumor in atypical location

Abstract

Glomus tumors are benign neoplasms that arise from neuromyoarterial glomus bodies accounting for <2% of soft-tissue tumors. Glomus tumors represent around 1–5% of all soft-tissue tumors and 1–5% of all hand tumors. About 75% of these tumors occur in hand with 75–90% of these occurring in characteristic subungual location. Extradigital location of glomus tumor is very rare. We report an exceptional case of extradigital glomus tumor causing thigh pain, where there were a pair of lesions both in periosteum and intramuscular location. A 47-year-old male with complaints of pain over medial aspect of the left lower thigh for 2 years on ultrasound revealed well-defined solid hypoechoic lesions within the left vastus medialis muscle and cortical-based lesion abutting the periosteum of distal diaphysis of the left femur on medial aspect. These lesions were hypointense on T1W, hyperintense on T2W and showed early homogenous enhancement on MRI. Histopathology revealed glomus tumors, which commonly occur in digits. Glomus tumors located in both periosteal and intramuscular locations in thigh were in very uncommon. Non-specific presentation with pain in such cases remains a diagnostic dilemma. Role of multimodality imaging and histopathology correlation is important in such situation.