Contributed by Joel F. Gradowski, MD and Csaba Galambos, MD
Published on line in June 2007
A seven year old boy presented in 2006 with multiple skin lesions. A biopsy of one of the lesions was diagnosed as cutaneous anaplastic large cell lymphoma by another institution. He was treated with topical Aldara. He did not receive any systemic therapy. All of the lesions regressed with the exception of a lesion on his left chest wall. The lesion continued to enlarge and became ulcerated. Serial imaging studies did not demonstrate any evidence of systemic disease. The peripheral blood differential was normal. The lesion was surgically excised in early 2007.
A resection specimen with skin ellipse and underlying soft tissue was received. In the central aspect of the specimen there was a 1.7 cm lesion with a raised rim and a depressed central indentation with ulceration. Sectioning of the specimen revealed a fleshy tan tumor. The surgical margins of resection appeared negative. Material was reserved for flow cytometry, cytogenetics, and molecular analysis. Direct smears were prepared.
Histologic examination revealed an infiltrate of discohesive atypical lymphoid cells at the dermal-epidermal junction extending to the deep dermis. The overlying skin was ulcerated with neutrophilic inflammation and crust. In the dermis the atypical lymphoid cells were present in large sheets. They varied in size and had pale abundant cytoplasm. Nuclei were irregularly shaped; some cells had multiple nuclei. Cells with very atypical, bizarre nuclei were also seen. One or multiple, prominent nucleoli were noted. Mitoses including atypical forms were prominent. Small mature appearing lymphocytes and histiocytes were scattered throughout the tumor.
Immunohistochemical studies demonstrated that the atypical lymphoid cells did not express the B-cell markers CD20 and CD79a. The majority of the atypical lymphoid cells did not express CD3. The atypical lymphoid cells did express CD4, CD30, CD43, TIA1, and Perforin. The atypical lymphoid cells were negative for CD2, CD5, CD7, and CD8. Importantly, the atypical lymphoid cells did not express ALK or EMA. Interspersed were CD3 expressing small mature appearing lymphocytes and CD68 expressing histiocytes.