CD30+ lymphoproliferative disorder in a patient with metastatic papillary thyroid carcinoma

Background CD30+ lymphoproliferative disorders are rare and may feature a wide variety of presentations that mimic other conditions. Purpose A man with metastatic papillary thyroid carcinoma to skin who subsequently developed cutaneous anaplastic large cell lymphoma is described. Methods The PubMed medical database was used to search the following terms separately and in combination: ALCL, anaplastic large cell lymphoma ALCL, cutaneous anaplastic large cell lymphoma CALCL, cutaneous t-cell lymphoma CTCL, large t-cell lymphoma LTCL, lymphoproliferative, lymphomatoid papulosis LyP, mimic, papillary, thyroid cancer. Results CD30+ cutaneous anaplastic large cell lymphoma was diagnosed in a man with metastatic papillary thyroid carcinoma based on the temporal, histologic, and immunochemical features of an enlarging lesion. To the best of our knowledge, this is the initial description of a CD30+ lymphoproliferative disorder occurring in a patient with primary carcinoma of the thyroid. Conclusion Cutaneous lesions may present with various morphologies. Our patient had a previous history of metastatic papillary thyroid carcinoma to skin. His new chest lesion was originally suspected to be either an infection or a cutaneous metastasis. Multiple biopsies, not only for microscopic evaluation but also cultures for infectious organisms, were performed. Unexpectedly, a CD30+ lymphoproliferative disorder was diagnosed; subsequently the tumor spontaneously resolved. Therefore, when skin lesions appear that have more than one clinical presentation, it may be prudent for the clinician to collect representative samples of each distinct morphology to assure that an accurate diagnosis is established.