Widespread cutaneous and perioral metastases of mesothelioma.
BACKGROUND
Cutaneous involvement by mesothelioma represents a rare occurrence from an uncommon neoplasm. Most cases have resulted from local extension of an underlying body cavity mesothelioma or from surgical site contamination. We could only find six previously reported cases of distant cutaneous metastases of mesothelioma.


METHODS
We describe a case of metastatic mesothelioma involving multiple skin sites and the lip in a 64-year-old man with an underlying primary pleural mesothelioma.


RESULTS
A 64-year-old man presented with a lip lesion clinically diagnosed as keratoacanthoma vs. squamous cell carcinoma. Evaluation of the lip biopsy revealed tubulo-glandular and acinar-like arrangements of plump epithelioid cells with a hobnailed appearance, vesicular nuclei, and prominent nucleoli. The initial impression of metastatic carcinoma was revised to probable mesothelioma upon discovery of a previous history of pleural mesothelioma. Positive immunohistochemical stains for anti-cytokeratin, anti-calretinin, and HBME-1 and negative stains for anti-CEA, Leu-M1, B72.3, and Ber-Ep4 confirmed the diagnosis.


CONCLUSIONS
We report a rare example of multiple cutaneous metastases of mesothelioma. We also demonstrate the usefulness of relatively new and specific immunomarkers for mesothelioma vs. adenocarcinoma. Metastatic mesothelioma to the skin or lip is a very rare occurrence but should be considered in the differential diagnosis of malignant epithelioid neoplasms.
D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D002294:Carcinoma, Squamous Cell / Q000473:pathology; D003937:Diagnosis, Differential; D006801:Humans; D007150:Immunohistochemistry; D007636:Keratoacanthoma / Q000473:pathology; D008048:Lip Neoplasms / Q000378:metabolism / Q000556:secondary*; D008297:Male; D008654:Mesothelioma / Q000378:metabolism / Q000556:secondary*; D010997:Pleural Neoplasms / Q000378:metabolism / Q000473:pathology*; D012878:Skin Neoplasms / Q000378:metabolism / Q000556:secondary*
D014408:Biomarkers, Tumor