Cutaneous collagenoma

Epidemiology

Cutaneous collagenomas are rare benign cutaneous stromal lesions. They can be subdivided into giant cell collagenoma and solitary sclerotic fibroma (circumscribed storiform collagenoma, sclerotic fibroma, hypocellular fibroma). The latter may represent the regressed end-stage of dermatofibroma.

Histopathology

There is a nodular circumscribed proliferation of collagen fibres. The lesions are of low cellularity but with varying numbers of stellate mononuclear and giant multinucleate cells, the latter being particularly prominent in giant cell collagenoma.

Immunohistochemistry

	giant cell collagenoma	solitary sclerotic fibroma
Vimentin	1/11	3/31
Factor XIIIa	0/11	3/31
CD34	1/11	3/31
Factor VIIIRA	0/11	0/13
S-100	0/11	0/31
HHF35	0/11	0/31
Desmin	0/11	0/31
CD68	0/11	0/31
MIB-1	0/11	0/31

Ultrastructure

Only contain genuine multinucleate cells. The apparent multinucleate cells of solitary sclerotic fibroma are closely apposed stellate mononuclear cells.

Prognosis

Cutaneous collagenomas are benign, although occasional recurrences of solitary sclerotic fibroma have been reported.

References

1Ramos, D., Monteagudo, C., Carda, C., Ramon, D., Gonzalez-Devesa, M., Llombart-Bosch A. Ultrastructural and immunohistochemical characterization of the so- called giant multinucleate cells in cutaneous collagenomas. Histopathology 2002;41:134-143.

This page last revised 10.6.2002.