Isolated subcutaneous nodules (pseudorheumatoid).

Ten patients with isolated subcutaneous nodules histologically similar to rheumatoid nodules were studied. Because of the intense fibroblastic reaction in one such nodule, it was initially mistaken for a fibrosarcoma. The nodules tended to be multiple and recurrent, with eventual spontaneous regression, and they were not associated with any systemic illness. The etiology of these lesions is unclear but the possibility of subsequent development of systemic rheumatoid disease is remote.