Intravascular immunoglobulin crystalloids in monoclonal cryoglubulinemia-associated dermatitis: ultrastructural findings.

A 46-year-old woman developed polyarthritis, purpuric skin rashes, nasal septal perforation and marginal furrowing of corneas in 1980. Monoclonal IgG, kappa cryoglobulinemia was found in the patient's serum. No underlying lymphoproliferative disorder has been found in ten years since her original diagnosis. In 1991, she developed palpable purpura on both lower extremities with subsequent necrosis and ulceration. A skin biopsy revealed fibrin thrombi within capillaries in the papillary dermis, and immunofluorescence studies showed IgG and light chain kappa within the fibrin thrombi. An electron microscopy study showed intravascular immunoglobulin crystalloid structures with a mean diameter of 80.3A degrees (8.03 nm), mixed with fibrin and red blood cells. The exclusive vascular location of these crystalloids may have implication in the pathogenesis of skin lesions.

Immunohistochemistry and electron microscopy in Langerhans cell histiocytosis confined to the skin.

Four cases of benign Langerhans cell histiocytosis limited to the skin were studied. In all three self-healing cases (cases 2, 3, and 4) many dense bodies, myelin bodies, and worm bodies were found. In one chronic case (case 1) none of these was identified. In all four cases, in addition to CD1, HLA-DR, and S-100 stains, interferon-gamma and S-100 beta-subunit were positive in the dermal tumor cells. Both interferon-gamma and S-100 beta-subunits were negative in the normal epidermal Langerhans cells. A comprehensive literature review yielded 87 cases of skin-limited Langerhans cell histiocytosis. These cases could be subgrouped into three categories: (1) those that resolved spontaneously, (2) those that responded to therapy and had no recurrence, and (3) those with persistent or recurrent lesions, not responding to therapy but still limited to the skin.