Lymphoproliferative Disorders

The document discusses various cutaneous lymphoproliferative disorders, highlighting the challenges in diagnosis due to variables such as patient complaint thresholds, clinical biopsy thresholds, and pathologic atypia thresholds. It notes that cutaneous T cell lymphoma cases often present with atypical clinical and histopathological features, and that antigen deletion and T cell receptor gene rearrangements are found in both inflammatory and neoplastic dermatoses. Cutaneous B cell lymphoma is often a secondary manifestation or the first sign of systemic B cell lymphoma, and the concept of skin-associated lymphoid tissue is somewhat valid. Pseudolymphoma requires further definition, and CD30 positive lymphoproliferative disorders of the skin, which include Hodgkin's disease, lymphomatoid papulosis, and large cell lymphoma, generally have a good prognosis when occurring separately from mycosis fungoides. The summary emphasizes the importance of careful clinicopathologic and light microscopic correlation for accurate diagnosis.