Nodular or tumoral melanosis consists of nodular or sheetlike deposits of melanophages in the dermis. When nodular melanosis is present, a completely regressed malignant melanoma is a major diagnostic consideration.
We present a case of nodular melanosis due to regression of a pigmented basal cell carcinoma with pilar differentiation. In addition to this case, we present five additional cases of epithelial neoplasms with melanin deposition in the stroma. In each case, the source of the melanin was non-neoplastic dendritic melanocytes intermingled among the tumor cells.
Therefore, if nodular melanosis is found, pigmented epithelial neoplasms should also be considered in the differential diagnosis.
National Naval Medical Center, Bethesda, Maryland (S.H.F., K.J.S.); LabCorp, Herndon, Virginia (H.G.S.); and Armed Forces Institute of Pathology, Washington, DC (G.P.L.), U.S.A.
Address correspondence and reprint requests to Dr. H.G. Skelton, Pathology, Labcorp, 13900 Park Center Road, Herndon, VA, 22071, U.S.A.
The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of the Army, the Department of the Navy, or the Department of Defense.