Introduction: We report two patients in whom a slowly growing erythematous thoracic lesion led to the diagnosis of an underlying plasmocytoma. After the treatment of the latter, the cutaneous lesions disappeared, strongly suggesting a link between the two manifestations.
Case reports: The two male patients, aged respectively 66 and 73 years old, had erythematous thoracic plaques. In both cases, extensive laboratory work-up and a histological examination of a cutaneous biopsy did not allow a precise diagnosis. The two patients had a solitary bony plasmocytoma located beneath the cutaneous plaques. The plasmocytomas were discovered respectively 2 and 4 years after the first cutaneous manifestations and were associated to histological non-specific lymph node hyperplasia. Treatment of the plasmocytoma led to the disappearance of skin lesions in both patients.
Discussion: In both cases, an erythematous scleroderma-like plaque associated to palpable peripheral and mediastinal lymph nodes, was located over a solitary bony plasmocytoma. Treatment of the plasmocytoma led to the disappearance of the cutaneous lesions, strongly suggesting a link between the two manifestations. Such an association has not been previously reported. We think this is a new entity, characterised by a scleroderma-like cutaneous plaque overlying a solitary bony plasmocytoma and associated to superficial and deep lymph node hyperplasia. We suggest to call it "plasmocytoma associated cutaneous lymph node syndrome". Its relationship to the POEMS syndrome and scleromyxedema are discussed. The pathophysiology remains completely unknown; the syndrome regresses after the treatment of the plasmocytoma.