This biopsy came from a patient in their 50s with multiple recurrent lesions on the lower extremities that would ulcerate and then regress. The clinical suspicion was for pityriasis lichenoides versus folliculitis. The epidermis is necrotic and there is a mixed infiltrate in the superficial dermis. I didn’t see viral cytopathic change, arthropod remants or folliculitis. I was concerned about a population of large atypical appearing lymphocytes in the superficial dermis and the immunohistochemistry studies showed that this population of cells stained with CD30 with a background of smaller CD3 positive T-cells. Given the clinical presentation and histologic findings, this fit well for lymphomatoid papulosis. In cases like this, my diagnosis is usually “CD30-positive lymphoproliferative disorder”, with a comment describing the lesion and recommendation for follow-up evaluation since there is a higher risk for development of hematologic malignancy in patients with lymphomatoid papulosis. Determining how many CD30 positive cells is too many can be a challenge. There are plenty of cautionary reports in the medical literature that show increased CD30-positive cells in conditions such as viral infections, drug reactions, arthropod assaults, and pityriasis lichenoides, among others. Most authors stress careful clinical pathological correlation when making this diagnosis. There is a nice free full text article in Blood from Oct. 2011 from the Cutaneous Lymphoma Task Force of the European Organization for Research and Treatment of Cancer, the International Society for Cutaneous Lymphomas, and the United States Cutaneous Lymphoma Consortium, with therapeutic recommendations for CD30-positive lymphoproliferative disorders.
- EORTC, ISCL, and USCLC consensus recommendations for the treatment of primary cutaneous CD30-positive lymphoproliferative disorders: lymphomatoid papulosis and primary cutaneous anaplastic large-cell lymphoma. Blood. 2011 Oct 13;118(15):4024-35. Epub 2011 Aug 12. Kempf W et al.
- In search of prognostic indicators for lymphomatoid papulosis: A retrospective study of 123 patients. J Am Acad Dermatol. 2011 Oct 7. de Souza A, El-Azhary RA, Camilleri MJ, Wada DA, Appert DL, Gibson LE.
- CD30+ lymphoproliferative disorders: histopathology, differential diagnosis, new variants, and simulators. J Cutan Pathol. 2006 Feb;33 Suppl 1:58-70. Kempf W.