Glomus tumor of the finger

CLINICAL HISTORY

The patient is a 63-year-old woman who has a three-month history of severe pain and discoloration at the nail bed of her right thumb. Routine radiographs were normal. An ultrasound examination with color and power Doppler was performed.

FINDINGS

FIGURE A. Longitudinal ultrasound image at the dorsal aspect of the distal phalanx of the right thumb demonstrates an isoechoic mass (arrowheads) that is difficult to separate from the surrounding soft tissues. There is slight erosion of the underlying bone. The normal left side is included for comparison. FIGURE B. Longitudinal color Doppler ultrasound image of right thumb demonstrates abundant vascularity that is slightly splayed around the mass (arrowhead). FIGURE C. Longitudinal power Doppler ultrasound image at the same level, again showing abundant vascularity.

DIAGNOSIS

Glomus tumor of the finger.

DIFFERENTIAL DIAGNOSIS

None. Appearance and location are pathognomonic.

DISCUSSION

The glomus tumor is a benign neoplasm that is typically located in the subungual region of the distal phalanx of the finger.¹ This lesion is more common in women and typically presents with a small red-blue nodule under the fingernail that causes pain, exquisite tenderness, and temperature sensitivity.¹ The nail may be ridged and discolored.¹ Glomus tumors of the finger may be hard to detect on gray-scale sonography but typically appear hypoechoic, and erosion of the adjacent bone may be seen.^1,2 Color Doppler analysis shows markedly increased blood flow and is helpful in confirming the diagnosis.^2,3 Surgical excision is curative, but if the lesion is not removed completely, local recurrence is common.¹ Sonography may be useful for preoperative assessment to ensure complete removal.^2,3

REFERENCES
1. Fornage BD. Glomus tumors in the fingers: diagnosis with US. Radiology 1988;167(1):183-185.
2. Chen SH, Chen YL, Cheng MH, et al. The use of ultrasonography in preoperative localization of digital glomus tumors. Plast Reconstr Surg 2003;112(1):115-119.
3. Matsunaga A, Ochiai T, Abe I, et al. Subungual glomus tumour: evaluation of ultrasound imaging in preoperative assessment. Eur J Dermatol 2007;17(1):67-69.

Case submitted by Dr. Levon N. Nazarian, a professor of radiology at Thomas Jefferson University Hospital in Philadelphia, Pennsylvania.