Glomus tumor - soft tissue

Summary
Description

Glomus tumor is a rare and benign vascular tumor that occurs in a subungual location of the hands and feet, but may also present as a subcutaneous soft tissue mass. The lesion usually causes severe pain and sensitivity to cold.

People and Age
Average age is 30 to 50 years.
Symptoms and Presentation
Severe pain, point tenderness, and temperature sensitivity.
Brief description of the xray
No findings on plain radiographs
Brief desc of tx
Surgical excision is curative.
Tumor Name
Tumor Type
Benign or Malignant
Body region
Most Common Bones
Tumor behavior
Tumor density
Complete Information on this Tumor
Introduction and Definition

Glomus tumors arise from the glomus body, an neuroarterial structure that may have a role in thermoregulation. The lesions present most frequently during the fourth and fifth decade of life although they can be found in any age and at any site. The subungual tumors affect women three times more commonly than men. The lesions can also arise in the skin and subcutaneous structures.

Clinically, glomus tumors are characterized by a triad of sensitivity to cold, localized tenderness and severe intermittent pain. The pain can be excruciating and is described as a burning or bursting.The exact cause of the pain is not completely understood, but nerve fibers containing the pain neurotransmitter substance P have been identified in the tumor.

Incidence and Demographics
Glomus tumor is a rare and benign vascular tumor. The normal glomus unit is a neuromyoarterial apparatus that functions to regulate skin circulation and is found subungually, on the finger tip pulp, on the base of the foot and the rest of body in descending order. The most common site of glomus tumors is subungual and 75% of the lesions occur in the hand.

The lesions present most frequently during the fourth and fifth decade of life although they can be found in any age and at any site. The subungual tumors affect women three times more commonly than men.
Symptoms and Presentation

At initial presentation, the lesion may not be palpable and the characteristic blue-purple discoloration may not be visible. The pt reports a painful area which can be extremely well localized.

Clinically, glomus tumors are characterized by a triad of sensitivity to cold, localized tenderness and severe intermittent pain. The pain can be excruciating and is described as a burning or bursting.The exact cause of the pain is not completely understood, but nerve fibers containing the pain neurotransmitter substance P have been identified in the tumor.

One diagnostic test is sensitivity to pressure with a very small object, such as the head of a pin or a fine blunt k-wire. Cold sensitivity can be tested with ice baths. Application of a tourniquet is said to relieve the pain, which returns rapidly when the tourniquet is released.

The lesion may have a visible blue color.

X-Ray Appearance and Advanced Imaging Findings
Plain radiographs do not show the lesion, although bony erosions have been reported in long-standing lesions.
MRI Findings
Glomus tumors appear as a dark on T1 and high and homogeneous signal intensity on T2 weighted images. This signal pattern is seen with most tumors. The location, clinical features, and small size should suggest glomus tumor in most cases. The typical lesion is only 7mm in size, and may be impossible to see on a low-field MRI scan. Gadolinium contrast agent and fat saturation images may reveal the mass. MRI is useful for the detection of lesions in the soft tissues. The clinical differential of a painful, subcutaneous tumors include the ANGEL lesions: Angiolipoma, Neuroma, Glomus tumor, Eccrine spiradenoma, Leiomyoma
Laboratory Findings
no lab tests are useful
Differential Diagnosis
ANGEL lesions: Angiolipoma, Neuroma, Glomus tumor, Eccrine spiradenoma, Leiomyoma
Preferred Biopsy Technique for this Tumor
excisional
Histopathology findings
Grossly, the tumors are usually less than one cm. in size, and appear as small red-blue nodulas. The lesion appears as a localized dark red or blue lesion beneath the finger nail, but the subungual lesions can be difficult to detect on clinical examination. Radiographs of the distal phalanx show a small scalloped osteolytic defect with a sclerotic border. Under the microscope, glomus tumors are found at the dermal and subdermal junction and have a fibrous capsule. They are made of an afferent arteriole, anastomotic vessel, and collecting venule. These vascular structures are surrounded by rounded uniform epithelioid cells with granular cytoplasm known as glomus cells or pericytes. Also present are smooth muscle cells and non-myelinated nerve cells. There is no pleomorphism or mitotic activity. There are three forms of glomus tumors: vascular, myxoid and solid. The vascular form consists of mostly vessels with little epithelioid component. The solid form has sheets of glomus cells with few vessels. Glomus tumors stain positive for the smooth muscle marker actin.
Treatment Options for this Tumor
Treatment of glomus tumors consists of surgical excision.
Preferred Margin for this Tumor
Marginal
Outcomes of Treatment and Prognosis
Relief of pain is usually intermediate after surgery.
Special and Unusual Features
Johnson, DL et al., Intraosseous Glomus Tumor of the Phalanx: A Case Report, Journal of Hand Surgery (American):18(6):1026-8, November, 1993. Kishimoto S et al., Immunohistochemical demonstration of Substance-P containing nerve fibers in glomus tumors. Br J Dermatol 113:213, 1985. Murphey, MD et al., Musculoskeletal Angiomatous Lesions: Radiologic-Pathologic Correlation, Radiographic, 15:893917, July, 1995. Takei, TR and EA Nalebuff, Extradigital Glomlis Tumor, Journal of Hand Surgery (British), 20B(3):409-412, June, 1995. Sunderraj, S et al., Primary Intra-Osseous Glomus Tumor, Histopathology, 14(5):532-536, May, 1989. Heys, SD et al., Glomus Tumor: An Analysis of 43 Patients and Review of the Literature, British Journal of Surgery, 79:345-347, April, 1992. Vandevender, DK and RA Daley, Benign and Malignant Vascular Tumors of the Upper Extremity, Hand Clinics, 11 (2): 161 - 179, May, 1995. Huvos, Andrew, Bone Tumors Diaonosis. Treatment and Prognosis, W.B. Saunders, Co., 1991.