This 69 year old man presented with multiple ill-defined tumors on his back. There was a clinical concern for metastases. Adenoid cystic carcinoma is a rare primary skin tumor, with probable eccrine origin. The characteristic histologic feature is the cribriforming architecture, that is, the rigid punched-out-appearing holes within the individual islands. There are also abnormal pink and bluish mucinous secretions. Basal cell carcinoma has an adenoid basal pattern, which mimics adenoid cystic carcinoma, but should have areas of more recognizable basal cell carcinoma. This lesion metastasized, which would also argue against basal cell carcinoma. Treatment of adenoid cystic carcinoma is local control, but as this case illustrates, metastases may occur.
There is an infiltrating neoplasm within the dermis, unattached to the overlying epidermis. The neoplasm consists of infiltrating nests and cords of basaloid cells. At low power, a cribriforming architecture is appreciated.