eMedicine Specialties > Dermatology > Diseases of the Vessels

Glomus Tumor

Author: Jon H Meyerle, MD, Assistant Professor, Department of Dermatology, Johns Hopkins University School of Medicine; Chief, Immunodermatology, Dermatology Laboratory Director, Department of Dermatology, Walter Reed Army Medical Center and National Naval Medical Center
Coauthor(s): Erin L Spillane, MD, Resident Physician, Department of Dermatology, Walter Reed Army Medical Center
Contributor Information and Disclosures

Updated: Aug 5, 2010

Introduction

Background

Glomus tumors are uncommon benign lesions that typical present in young adults (ages 20-40) as small, blue-red papules or nodules of the distal extremities, with a predilection for subungual sites. Glomus tumors are typically painful, often causing paroxysmal pain in response to temperature changes or pressure. 

Glomus tumors are thought to arise from the glomus body, a thermoregulatory shunt concentrated in the fingers and toes. Two variants are noted: solitary glomus tumors and multiple glomus tumors, which are also known as glomangiomas or glomuvenous malformations. Each variant has distinct clinical and histopathologic characteristics. Note the images below.

Pathophysiology

Glomus tumors are thought to represent neoplastic proliferations of modified smooth muscle cells originating from preexisting normal glomus cell populations. Glomus cell populations are specialized arteriovenous anastomoses found most often in the fingers and are characterized by Sucquet-Hoyer canals, which play an important role in thermoregulation.

Interestingly, while glomus tumors predominate on the hands and fingers especially, they can occur in a wide anatomic distribution, to include sites not known to contain glomus cells. One explanation for this finding is that these tumors may arise from perivascular cells that can differentiate into glomus cells.

Most glomus tumors are solitary and sporadic, but some cases of glomus tumor are multiple and can be segmental in distribution. These disseminated variants of glomus tumor are classically seen in children and have an autosomal dominant inheritance pattern.

Frequency

United States

These hamartomas account for 1-5% of all soft tissue tumors of the hand¹ ; however, the true incidence of glomus tumors is unknown, likely as a result of misdiagnosis of many of these lesions as hemangiomas or venous malformations. The multiple variant of glomus tumor is much less common, accounting for less than 10% of all reported cases.

Mortality/Morbidity

Patients with glomus tumors classically present with paroxysmal severe pain, often precipitated by cold, pressure, or dependency. Pain is more frequent in solitary lesions; multiple tumors—classically seen as glomuvenous malformations—arise in younger patients and tend to be asymptomatic.

In one report, a patient with more than 400 glomus tumors had thrombocytopenia as a result of platelet sequestration (ie, Kasabach-Merritt syndrome). 

Extremely rare instances of malignant transformation within glomus tumors have been described; these typically represent a locally infiltrative malignancy; however, metastases have been described.^2,3

Sex

Glomus tumors in general show no sex predilection; however, solitary subungual lesions are more commonly observed in women and multiple lesions are slightly more common in men.

Age

Solitary glomus tumors can occur at any age, but they are most frequent in young adults. Glomangiomas, or glomuvenous malformations, are often multifocal and typically present in children; indeed, many are congenitally present.

Clinical

History

Patients with solitary glomus tumors usually have paroxysmal pain, which can be severe and can be exacerbated by pressure or temperature changes, especially cold. Multiple glomus tumors can also be painful, but this feature is less common, and the pain is usually not severe.

Patients with multiple lesions often seek medical attention because they are worried or have cosmetic concerns. Because multiple glomus tumors are inherited as an autosomal dominant condition, a family history of similar lesions may be helpful for diagnosis.

Extracutaneous sites have been reported, including involvement of the gastrointestinal tract, trachea, nerve, bone, mediastinum, liver, pancreas, and ovary.^4,5

Physical

Solitary glomus tumors have the following characteristics:

• Blue or red blanchable papules or nodules in deep dermis or subcutis 
• Acral location, most commonly, especially subungual
• Size usually smaller than 2 cm

The multiple variant is subdivided into regional or localized, disseminated, and congenital plaquelike forms, as follows:

• Regional variant - Consists of blue-to-purple partially compressible papules or nodules that are grouped and limited to a specific area, most commonly to an extremity
• Disseminated type - Consists of multiple lesions distributed over the body with no specific grouping; less common than the regional variant
• Congenital plaquelike glomus tumors - Consist of either grouped papules that coalesce to form indurated plaques or clusters of discrete nodules; rarest variant of multiple glomus tumors

Two useful findings for diagnosing glomus tumors, particularly solitary painful glomus tumors (especially those under a nail), are the following:

• Hildreth sign - Disappearance of pain after application of a tourniquet proximally on the arm
• Love test - Eliciting pain by applying pressure to a precise area with the tip of a pencil

Features of glomangiosarcomas may include the following:

• Size larger than 2 cm
• Rapid growth
• Deep soft tissue involvement

Causes

Glomus tumors are neoplasms caused by a proliferation of glomus cells, which make up a portion of the glomus body. The initiating event for glomus cell proliferation is unknown. Some authors have postulated that trauma induces solitary subungual glomus tumors, although this theory is not well studied.

Most multiple glomus tumors, especially the disseminated form, are inherited in an autosomal dominant pattern with incomplete penetrance. Most hereditary glomangiomas are associated with defects in the glomulin gene, located on chromosome 1.

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