Extradigital Glomus Tumor of the Forearm: Lessons from a Missed Diagnosis

Glomus tumors are benign vascular tumors that are rare and most usually located in the nail bed. They may go undetected when they are found in unusual places, such as the forearm, and hence, cause a delay in diagnosis and treatment. In this report, we have discussed a 34-year-old man with a history of forearm pain, which was diagnosed as a glomus tumor, thus illustrating the importance of a high index of suspicion about unusual sites of such a tumor in cases of persistent pain to make an early diagnosis and enable faster treatment.

A 34-year-old man presented with a history of local forearm pain over a long period, with a tender purplish subcutaneous swelling over the medial aspect of the upper forearm. The pain was chronic and exaggerated even on light touch, with no history of trauma or family history. The clinical observation showed a non-indurated, solitary and non-inflammatory lesion, without any inflammation. Ultrasound and magnetic resonance imaging showed a clearly defined, superficial, subcutaneous lesion, with homogeneous post-contrast enhancement, directly over the basilic vein. The patient was surgically treated by wide local excision with an elliptical incision. In the course of surgery, a well-circumscribed dark red mass was found and excised in its entirety. A histopathological analysis of a well-circumscribed dermal and subcutaneous tumor of glomus cells in the form of a nest confirmed the diagnosis of glomangioma. At 1-year follow-up, the patient had no symptoms. This case illustrates the possibility of extradigital glomus tumors in individuals who present with chronic localized unexplained forearm pain.

The case highlights the importance of diagnosing extradigital glomus tumors as a potential cause of chronic and localized pain in the limbs. Their abnormal location and insidious presentation often lead to neglect of such tumors, and therefore, their diagnosis becomes late and causes the patient undue discomfort. Even though clinical suspicion and appropriate imaging are useful in the early diagnosis, surgical excision is the treatment of choice, which offers complete relief. This report highlights the fact that early diagnosis can enhance the outcome of such cases.