Contributed by Allene Gagliano, MD, Leena Lourduraj, MD and Drazen Jukic, MD, PhD
Published on line in June 2005
74 yo female with inflamed "seborrheic keratosis" on dorsum of right ankle. Her only other pertinent history is that of a seborrheic keratosis removed in eight years ago. We received a pale-tan fragment of cutis and subcutis that corresponded to a shave biopsy, which was 1.3 x 1.0 x 0.2 cm.
Fig. 1: Low power H&E of shave biopsy specimen.
Figs. 2 and 3: 10X H&E of shave biopsy demonstrating desmoplastic spindle cell tumor.
Fig. 4: High power H&E.
Fig. 5: S100 immunostain demonstrating strong diffuse staining throughout.
Fig. 6: HMB45 immunostain demonstrating loss of staining in desmoplastic cells.
Fig. 7 and 8: MelanA immunostain demonstrating loss of staining in some desmoplastic cell nests.
Fig. 9: Tyrosinase demonstrating decreased staining in desmoplastic cells.
Fig. 10: Ki67 demonstrating rare positive cells.