Glomus Tumor - Pathology

Introduction

Rare benign tumor of the glomus body, often occurring in the subungual region
- may involve either the soft tissue and/or bone
- frequently associated with a delay in diagnosis
- glomus tumor may also be called a paraganglioma
Epidemiology
- demographics
  - occurs in patients 20 to 40 years of age
- location
  - 75% occur in hand
  - 50% are subungual
  - 50% have erosions of distal phalanx (primary involvement of bone being very rare)
  - less common locations: palm, wrist, forearm, foot

Anatomy

Glomus body
- the glomus body is a perivascular temperature regulating structure frequently located at the tip of a digit or beneath the nail

Presentation

Symptoms (classic triad)
- paroxysmal pain
- exquisite tenderness to touch
- cold intolerance
Physical exam
- small bluish nodule
- often difficult to see, especially in the subungual location
- nail ridging or discoloration is common
- Love test
  - pressure to the area with a pinhead elicits exquisite pain
  - 100% sensitive, 78% accurate
- Hildreth test
  - tourniquet inflation reduces pain/tenderness and abolishes tenderness to the Love test
  - 92% sensitive, 91% specific

Imaging

Radiographs
- glomus tumors can produce a pressure erosion of the underlying bone and an associated deformity of the bone cortex
MRI
- helpful to establish diagnosis
- present as a low T1 signal and high T2 signal

Studies

Histology
- well-defined lesion lacking cellular atypia or mitotic activity
  - small round cells with dark nuclei
  - associated small vessels in a hyaline/myxoid stroma
- can show gland-like or nest structures, separated by stromal elements

Treatment

Complications