Large Solitary Glomus Tumor of the Wrist Involving the Radial Artery

Discussion

Glomus tumors are an established cause of pain in the subungual areas of the hand; numerous cases have been reported.^1,5,10,14 However, extradigital glomus tumors, particularly those involving the wrist, are rare, and only a few have been described. Given the lack of consistent findings and presentations, diagnosis is difficult. Case series have documented an overall 2:1 female-to-male predominance of glomus tumors,⁶ but extradigital tumors are more common in men (4.6:1 male-to-female ratio).³ Extradigital glomus tumors are commonly diagnosed between ages 40 and 80 years. Classic symptoms of subungual tumors include pain, localized tenderness, and cold hypersensitivity,^1,10 but symptoms are much more variable with extradigital locations. Previous trauma or injury to the lesion area is reported in 20% to 30% of cases before symptom onset.^3,15 Intravascular locations of glomus tumors are extremely rare; only 4 cases of tumors involving venous structures have been reported.^16-19 In the present case, the patient’s main complaints were pain and localized tenderness associated with a progressively increasing mass without any history of trauma. The large size of his mass (~2.5 cm in diameter) on examination was unique, as was involvement of the radial artery.

Misdiagnosis and delayed diagnosis of extradigital glomus tumors are common, and symptoms such as chronic pain typically persist for 7 to 11 years before the correct diagnosis is made.^1,10 On average, 2.5 physician consultants (including psychiatrists) evaluate the patient before glomus tumor is identified.¹⁰ There are other reports of atypical or ectopic glomus tumors taking 5 to 25 years to be diagnosed.^20-22 The differential diagnosis for glomus tumors includes hemangiomas, cellular or cavernous hemangiomas, vascular tumors, neuromas, neurofibromas, lipomas, paragangliomas, ganglion cysts, pigmented nevi, Pacinian corpuscle hyperplasia, and foreign bodies. A key element of clinical diagnosis is the disproportionate amount of pain and localized tenderness caused by the lesion relative to its size. The hypersensitivity of this tumor is thought to result from enlargement of the tumor and impingement on nearby Pacinian corpuscles, nerve endings in the skin that are responsible for sensitivity to vibration and pressure.^2,9

Plain radiographs can be useful in detecting glomus tumors of the hand but are less helpful with extradigital tumors, with identification rates of 24% in certain series.³ MRI is the most sensitive imaging modality for diagnosing glomus tumors of the hand; a detection rate of 80% to 100% has been reported in various case series.^3,11,12 Specificity of MRI for glomus tumors has been reported at 50%.^11,23 Placement of a radiographic marker directly over the area of most pain can assist in tumor localization.³ Glomus tumors typically have decreased signal intensity on T1-weighted images and increased intensity on T2-weighted images, but signal patterns are variable and particularly difficult to differentiate with small tumors. MRI is useful in the setting of recurrent glomus tumors, where incomplete excision is possible. In 24 cases of continued pain after glomus tumor excision, Theumann and colleagues²⁴ used MRI to identify a nodule consistent with recurrent glomus tumor in all patients. Three-dimensional contrast-enhanced magnetic resonance angiography (MRA) can also help diagnose glomus tumors while providing valuable information regarding size and location for surgical planning.^25,26 With MRA, it is crucial to evaluate the arterial or arteriovenous phase of imaging, as the glomus tumor is richly vascularized and shows contrast enhancement after intravenous injection of gadolinium.²⁷ Angiography, ultrasonography, thermography, and scintigraphy have all been used to diagnose glomus tumors but have shown limited utility and accuracy.¹¹

Treatment of glomus tumors is complete surgical excision because of their relatively small size and subcutaneous location. Resection success rates are consistently higher than 95%, with resolution of all symptoms.^1,10,14 Local recurrence of tumors after excision occurs in 1% to 33% of cases, depending on series, and may be immediate or delayed, with immediate recurrence commonly caused by inadequate excision.^1,10,15,28 Delayed recurrence is less common and presents several years after excision, typically with a new growth near the previous excision.¹⁰ Recurrence years after surgery may also represent multiple tumors unrecognized during initial workup and can be treated with repeat excision or radiotherapy.

Robert and colleagues²⁹ recently reported the case of a glomus tumor, on the dorsal aspect of the wrist, discovered incidentally in a 71-year-old patient and treated with surgical excision. Several years earlier, Chim and colleagues³⁰ described a similar case, of a large wrist glomus tumor worked up with MRI. In a retrospective review of all extradigital glomus tumors seen over a 20-year period, Schiefer and colleagues³ reported 4 glomus tumors of the wrist out of 56 tumors total. The most common sites were forearm (11 cases) and knee (10 cases), and the majority of patients presented with pain and localized tenderness. Mean tumor size was 0.66 cm (range, 0.1-0.3 cm), with 77% of tumors less than 1 cm. Our patient’s 2.7×2.6×1.1-cm tumor was large for a glomus tumor. Its involvement with the radial artery feeding vessels likely contributed to its large and progressively increasing size. It is worth noting that, in the series by Schiefer and colleagues,³ the only patient with symptoms persisting after excision had a large (3 cm in diameter) deep tumor of the foot; the entire tumor was removed, and there was no recurrence by 10-year follow-up. Folpe and colleagues⁷ suggested that deep tumors larger than 2 cm should be at higher suspicion for malignancy. Joseph and Posner²¹ reported 3 cases of glomus tumors, on the ulnar side of the wrist, diagnosed with help of a provocative test using ethyl chloride spray.