CASE                               22                               

A 38-year-old woman is referred to you for “excruciating” pain in the left long fingertip, specifically at the base of the nail. She reports pain throughout the day and exquisite tenderness that has been ongoing for 4 years. There was no antecedent trauma. She reports that it is causing tension in her marriage and that her husband may be considering divorce. The digit and nail appear completely normal on inspection.

What is the most likely diagnosis?

1. Neuroma

2. Neurolemmoma

3. Paronychial infection

4. Glomus tumor

5. Malingering

Discussion

The correct answer is (D). It is a rare, benign neoplasm, which accounts for 1% to 4.5% of hand tumors. The mass is frequently too small to be identified on physical

examination. The average length of time to diagnosis is 2 to 7 years from the onset of symptoms. Tragically, many of the patients with glomus tumors suffer for years because they are thought to be malingering or have other psychosocial disorders before a proper diagnosis is made. The masses are typically very painful. The nail bed is a typical location of the mass, although they can be found volarly. Neuromas are less common distal to the trifurcation of the digital nerve and are more typically found after trauma. Neurolemmoma, or schwannoma, is more often painless and is very rare in the fingertip. A paronychial infection would present with swelling and redness on inspection and would not be present for 4 years.

What do you expect on physical examination?

1. Relief of symptoms when the tip of a ballpoint pen presses on the lesion

2. Relief of symptoms when the finger is placed in ice water

3. Relief of symptoms when a blood pressure cuff is raised on an elevated arm

4. Radiating pain when the digital nerve is percussed.

Discussion

The correct answer is (C). Love’s pin test (a tip of a pen, head of a pin, or K-wire is pressed on the mass and causes pain) has a reported sensitivity and specificity of 100%. Placing the finger in ice water or cooling it with cold spray increases pain with a sensitivity and specificity of 100%. Cold intolerance is characteristic of glomus tumors. Relief of symptoms with exsanguination and tourniquet elevation (Hildreth’s test) is 77% sensitive and 100% specific. A Tinel’s test is characteristic of a neuroma, not a glomus tumor.

What is the most appropriate next step in management of this lesion?

1. Fine needle aspiration (FNA)

2. Steroid injection

3. Incisional biopsy

4. Excisional biopsy

5. Amputation

Discussion

The correct answer is (D). Excisional biopsy is both therapeutic and diagnostic. FNA does not have a role in glomus tumor treatment. Steroid injection does not treat glomus tumors. The tumors are typically small (3–5 mm) and well-encapsulated, therefore excisional biopsy is the preferred treatment.

What do you expect to see on pathology?

1. Smooth muscle cells and surrounding vascular tissue

2. Nerve fiber overgrowth

3. Capillary overgrowth with atypical endothelium

4. Fibroblastic proliferation

5. Cystic structure filled with synovial fluid

Discussion

The correct answer is (A). Glomus bodies are a neuromyoarterial apparatus that controls arteriovenous shunting in terminal vessels. The function is to control blood flow in the digits. They are made up of smooth muscle cells and vascular tissue. Nerve fiber overgrowth is associated with a neuroma. Capillary overgrowth with atypical endothelium is found in hemangiomas. Fibroblastic proliferation is typical of fibromas. A cystic structure filled with synovial fluid is consistent with a mucous cyst.

Objectives: Did you learn...?

Recognize the presentation of glomus tumor? Pinpoint the findings on physical examination? Understand the treatment and pathology?