Glomus Extradigital Tumor: A Case Report of an Extradigital Glomus Tumor on the Wrist and Comprehensive Review of Glomus Tumors.

A glomus tumor is a neoplasm composed of cells from the glomus body which is a contractile neuromyoarterial structure that affects blood pressure and thermoregulation by altering cutaneous blood flow. This cutaneous tumor can be benign or rarely malignant, solitary or multiple, and digital or extradigital. A benign glomus tumor usually presents as a non-familial, solitary, and subungual lesion. Multiple glomus tumors are less common, may be autosomal dominantly inherited, and extradigital. In contrast to a digital glomus tumor that often occurs within the nailbed or fingertip pulp of a young woman, a glomus extradigital tumor (GET) typically appears on the extremity or trunk of an older man. The diagnosis of a glomus tumor may be suspected based on clinical evaluation; it classically presents with a clinical triad of symptoms which includes lesion-associated tenderness, pin-point pressure pain, and cold sensitivity. However, cold-induced exacerbation of pain is frequently absent in extradigital glomus tumors; this may contribute to a delay in establishing the diagnosis of a glomus tumor in these individuals. Radiographic studies can support the diagnosis, but tissue specimen examination is necessary to establish the diagnosis. Resolution of tumor-associated pain is usually achieved following the complete excision of the neoplasm. A woman with a glomus tumor located on her wrist is described; her painful tumor was not sensitive to cold and was misdiagnosed clinically as a possible foreign body reaction to either a wood splinter or glass shard. The diagnosis of an extradigital glomus tumor was established after a microscopic examination of the tissue specimen following an excisional biopsy using a 3-millimeter punch biopsy tool. The neoplasm-related pain ceased and did not recur after the tumor had been completely removed. In conclusion, a glomus tumor is included in the differential diagnosis of a painful cutaneous neoplasm; however, misdiagnosis and/or substantial delay in diagnosis may occur if the tumor is extradigital or it lacks cold sensitivity or both. Therefore, the clinician needs to entertain the possibility of an extradigital glomus tumor when evaluating a patient with a tender, temperature-insensitive skin lesion that is not located on the fingers or toes.