Glomus tumour

Epidemiology

Glomus tumours are mesenchymal tumours composed of modified smooth muscle cells representing a neoplastic counterpart of the perivascular glomus body. They are found across a wide a range from children to the elderly with a peak in young adults. The sex distribution is equal, apart from subungual glomus tumours which show a female predominance.

Clinical features

Most glomus tumours are small benign neoplasms of the dermis or subcutis, occuring most commonly in the distal extremities (subungula or lateral digits). They also rarely occur in the gastrointestinal tract, bone, nerve, mediastinum, lung3 and genitourinary tract.

Macroscopic appearances

Most are blue-red nodules, less than 1 cm in diameter.

Histopathology

The common glomus tumour is composed of capillary-sized vessels surrounded by collars of glomus cells. The glomus cells are round with a rounded nucleus. The cell outline is sharply defined, particularly with PAS or toluidine blue stains. Occasionally, abundant eosinophilic cytoplasm confers an "oncocytic" appearance. Intravascular growth and signet-ring cell change have been reported. glomangiomas show a transition form glomus cells with elongated smooth muscle cells.

It is proposed that glomus tumours be subdivided into:

Immunohistochemistry

Smooth muscle actin

40/401, 31/342

Desmin

2/321, 0/342

Calponin

5/111, 25/302

h-Caldesmon

7/121, 27/312

Collagen type IV (investing individual cells)

8/81, 31/342

Vimentin

14/141, 34/342

Laminin

30/332

Cytokeratin

0/341

Cytokeratin 18

0/342

S-100

0/341, 0/342

CD34

5/271, 31/342

CD117

0/302

chromogranin

0/302

synaptophysin

0/302

CD20

0/342

CD45 (LCA)

0/342

HMB-45

never

Ultrastructure

The features are those of smooth muscle cells.

Differential diagnosis of atypical glomus tumour

Prognosis

The metastatic rate in those glomus tumours classified as malignant was 38% (8/21 cases, of whom 6 died).

 

References

1AL. Folpe, JC. Fanburg–Smith, M Miettinen, SW. Weiss. Atypical and Malignant Glomus Tumors. Analysis of 52 Cases, With a Proposal for the Reclassification of Glomus Tumors. Am J Surg Pathol 2001;25:1-12.

2Miettinen, M., Paal, E., Lasota, J., Sobin, L. H. Gastrointestinal glomus tumors: a clinicopathologic, immunohistochemical, and molecular genetic study of 32 cases. Am J Surg Pathol 2002;26:301-311

3Gaertner EM, Steinberg DM, Huber M, et al. Pulmonary and mediastinal glomus tumors--report of five cases including a pulmonary glomangiosarcoma: a clinicopathologic study with literature review. Am J Surg Pathol 2000; 24:1105-14

FM Enzinger and SW Weiss, Soft tissue tumours, third edition.

This page last revised 1.5.2002.