[Histopathologic lesions in erythromelalgia during essential thrombocythemia].

Erythromelalgia is a vascular disorder of the extremities and is sometimes related to myeloproliferative syndrome with thrombocythemia. We report the cutaneous histopathology in case of erythromelalgia that revealed a thrombocythemia vera. Small arteries were occluded by thrombi of different age and narrowing of the lumen occurred by intimal proliferation of smooth muscle cells. There was no involvement of venules or capillaries. These vascular changes are highly suggestive of erythromelalgia and have not to be confused with necrotizing and/or granulomatous angiitis because of absence of fibrinoid necrosis and sparse inflammatory cells.