Update in dermatopathology.

Inflammatory skin disease is a diagnostic challenge for both dermatologists and pathologists. Unlike the diagnosis of cutaneous neoplasms, biopsies of inflammatory disorders generally present a differential diagnosis for the pathologist. Similarly, the dermatologist is also presented with a clinical differential diagnosis prompting the biopsy. Assimilating all of the information is challenging yet rewarding when an accurate diagnosis is made. In this review we present several "newer" inflammatory diseases of the skin and discuss the differential diagnosis. Many of these entities are associated with underlying systemic disease, making early recognition and diagnosis critical. Pathologists should be familiar with these histopathologic findings to assist with the optimal clinical-pathological diagnosis.

Multiple eccrine poromas in the setting of total body irradiation and immunosuppression.

Eccrine poromas are benign, adnexal tumors that most often occur as a solitary lesion on the palm or sole. The occurrence of multiple eccrine poromas is extremely rare. In this report, we describe the development of several eccrine poromas in an acral distribution in a 42-year-old man. Before the appearance of these tumors, the patient had received total body irradiation and allogeneic bone marrow transplantation for treatment of acute lymphocytic leukemia. As a complication of the bone marrow transplant, the patient developed chronic graft-versus-host disease, which was treated with immunosuppressive therapy. We discuss this patient and review the available literature regarding multiple eccrine poromas.

Posttransplantation lymphoproliferative disease with features of lymphomatoid granulomatosis in a lung transplant patient.

A 58-year-old lung transplant patient developed worsening shortness of breath and indurated erythematous plaques on the lower left leg. A skin biopsy specimen revealed a dense angiocentric and angioinvasive infiltrate in the mid to reticular dermis and panniculus containing large, atypical lymphocytes with convoluted nuclei and prominent nucleoli. Immunohistochemical stains showed that the atypical cells were of B-cell origin, and that Epstein-Barr virus was present. Molecular studies demonstrated B-cell clonality. The patient was successfully treated with rituximab. The clinical and pathologic features in this case represent posttransplantation lymphoproliferative disease with features of lymphomatoid granulomatosis. The case also highlights the importance of clinical and pathologic examination of cutaneous lesions in the evaluation of lymphoproliferative disorders for patients undergoing transplantation.