A multidisciplinary approach to the diagnosis of cutaneous T-cell lymphomas

Defining early mycosis fungoides

This editorial review summarizes the results of 5 meetings sponsored by the International Society for Cutaneous Lymphoma at which the clinicopathologic and ancillary features of early mycosis fungoides were critically examined. Based on this analysis, an algorithm was developed for the diagnosis of early mycosis fungoides involving a holistic integration of clinical, histopathologic, immunopathologic, and molecular biological characteristics. A novel aspect of this algorithm is that it relies on multiple types of criteria rather than just one, for example, histopathology. Before its finalization, the proposed diagnostic algorithm will require validation and possibly further refinement at multiple centers during the next several years. It is anticipated that a more standardized approach to the diagnosis of early mycosis fungoides will have a beneficial impact on the epidemiology, prognostication, treatment, and analysis of clinical trials pertaining to this most common type of cutaneous lymphoma.

Granulomatous slack skin

Granulomatous slack skin is an extremely uncommon form of cutaneous T-cell lymphoma. We report a case occurring in a 29-year-old man, who had generalized, progressive skin lesions evolving to nodular swellings and folds in the flexural regions, and peripheral blood and marrow involvement. The biopsies were initially misinterpreted as xanthogranuloma or granulomatous inflammation. Histologically, the entire dermis and subcutis was infiltrated by non-necrotizing granulomas comprising mononuclear histiocytes, multinucleated giant cells and small lymphoid cells with irregularly folded nuclei, associated with loss of elastic fibres. The small lymphoid cells showed focal epidermotropism. Immunohistochemical studies showed that they were of T-lineage (CD3+, CD43+, CD45RO+). The multinucleated giant cells, which showed reactivity with the histiocytic markers CD68 and Mac387, were highlighted by intense, thick membrane staining with CD45, CD43 and CD45RO. Ultrastructurally, they exhibited features of macrophages with numerous surface villous processes and lysosomes. Greater awareness of this entity may facilitate more prompt and accurate diagnosis, obviating a futile search for a non-existent infective aetiology.