[Skip to Navigation]
Citations 0
Off-Center Fold
March 2011March 21, 2011

Violaceous Plaques in a Collarlike Distribution—Diagnosis

Author Affiliations




Arch Dermatol. 2011;147(3):345-350. doi:10.1001/archdermatol.2011.38-b

Histologic examination revealed infiltration of the dermis by epithelioid aggregates of tumor cells, primarily within the dermal lymphatics, consistent with metastatic adenocarcinoma. The tumor cells were highlighted by thyroid transcription factor 1 and cytokeratin 7 but were negative for cytokeratin 20, prostate-specific antigen, D2-40 antibody, and prostate acid phosphate. Findings from laboratory evaluation included elevated cancer antigen 125 and carcinoembryonic antigen levels, while prostate-specific antigen and cancer antigen 19-9 levels were within normal limits. The immunophenotypic profile and serologic test findings were most suggestive of a primary lung origin, but computed tomography of the chest, abdomen, and pelvis with and without contrast failed to reveal a primary source for the cutaneous metastases. The patient declined imaging to exclude a thyroid neoplasm, which could manifest the same histologic immunoprofile, as well as any further workup or treatment. He died in his home 3 weeks later.