Cutaneous Metastatic Breast Cancer Masked by Hidradenitis Suppurativa.

The appearance of cutaneous metastases from breast carcinoma is variable and can present as nodules or inflammation of the skin, mimicking benign skin conditions. In addition, the skin lesions may be the initial presentation of unsuspected visceral malignancy or the site of either persistence or recurrence of metastatic disease in an oncology patient with a history of a solid tumor. The features of a woman with metastatic breast cancer that presented as a nodule that was masked by her concurrent, new-onset, hidradenitis suppurativa are reported. The diagnosis was suspected when the skin nodule persisted after her hidradenitis suppurativa improved; the diagnosis of cutaneous metastasis was confirmed with a skin biopsy. Occult breast cancer (primary or recurrent disease) may be masked by an inflammatory condition, such as hidradenitis suppurativa. Therefore, if a primary dermatologic condition does not appropriately respond to therapy, pathologic evaluation may be warranted to exclude the possibility of another disease, such as cutaneous metastases from underlying visceral cancer.