Synonyms

• Glomangioma
• glomuvenous malformation

Category

Soft tissue

Behaviour

Benign

Gender

Female

Tissue of Origin

Vascular

Epidemiology

• Benign periVascular tumour
• Peak incidence in 3rd–5th decades
• Female predominance for subungual lesions
• Multiple glomus tumours: autosomal dominant, chromosome 1p21-22

Clinical Features

• Subungual: classic triad of pinpoint tenderness, cold sensitivity, paroxysmal pain
• Pain classically exquisite and out of proportion to size
• Bluish discolouration under nail
• Extra-digital: painless or mild pain

Location

• Subungual (fingers - distal phalanx) most common
• Palmar surface of hands
• Forearm, wrist, foot
• Multiple lesions: extremities and trunk

Imaging

• Subungual: small well-defined lesion on MRI (T2 hyperintense, avid enhancement)
• Bone erosion of distal phalanx on plain X-ray (50%)
• High-resolution ultrasound: hypoechoic Vascular nodule
• T2 hyperVascular lesion on MRI

Pathology

• Round glomus cells surrounding capillary-like vessels
• Smooth muscle cell origin - SMA positive
• Three subtypes: solid glomus tumour, glomangioma, glomangiomyoma
• Rare Malignant variant (glomangiosarcoma): large size, deep location, atypia

Genetics

• NOTCH family rearrangements in Benign glomus tumours
• Glomuvenous malformations: GLMN gene mutations
• Glomangiosarcoma: TP53, RB1 alterations

Treatment

• Surgical excision - curative
• Transungual or periungual approach for subungual lesions
• Complete excision essential to prevent recurrence

Prognosis

• Excellent - Benign with very low recurrence rate after complete excision
• Malignant glomus tumour (glomangiosarcoma): rare but aggressive
• Pain relief is immediate after excision

Key Points

• Classic clinical triad in subungual lesion is virtually diagnostic
• X-ray may show distal phalanx erosion - subtle but important finding
• MRI is investigation of choice for precise localisation pre-operatively
• Malignant variant characterised by large size (>2 cm), deep location, and nuclear atypia

Workup - Blood Tests

No specific blood tests

Workup - Local Imaging

• Plain radiograph - erosion of distal phalangeal tuft in subungual cases
• Ultrasound
• MRI
• CT - if glomus jugulare or deep-seated variant

Workup - Biopsy

• Excision biopsy - preferred for small lesions (diagnostic and curative)
• Histology: uniform round cells surrounding Vascular spaces
• IHC: SMA+, collagen IV+, CD34 Variable; h-caldesmon+
• Malignant glomus tumour: size >2 cm, deep location, High mitoses, atypical nuclei

Workup - Staging

• No staging required for Benign glomus tumour
• CT chest/abdomen/pelvis if malignant glomus tumour suspected

Workup - Other

• Complete subungual excision - nail removal required for adequate access
• NOTCH mutations in familial glomuvenous malformations

Follow-up Summary

• Post-operative review at 6 weeks to confirm wound healing and nail recovery (subungual lesions)
• No routine imaging required post-excision of confirmed Benign glomus tumour
• Discharge with documented advice on returning if symptoms (pain, cold sensitivity) recur
• Malignant glomus tumour (glomangiosarcoma): treat as High-grade STS - standard intensive Follow-up with CT chest