Dermatoscopic features of spiradenoma—a benign adnexal neoplasm—have not been described. We present a case of spiradenoma occurring on the occipital scalp (Figure 1A, 1B) that showed a structureless pattern and blue clods on dermatoscopy. The vascular pattern of serpentine, branched vessels (Figure 2) in combination with blue clods suggest a basal cell carcinoma (BCC) [1]. However, the blue clods in BCC represent nests of pigmented trichoblasts, whereas in this case of spiradenoma the blue clods correspond to hemorrhage, a frequent finding in spiradenoma. This example also demonstrates that branched vessels seen by dermatoscopy are not specific and that they can be found in any kind of adnexal neoplasm, not only in BCC.

Figures 3 and 4 show the histopathologic images of this tumor. One can see large aggregations containing two cell populations, small basaloid cells on one side and large cuboidal cells on the other, and a prominent PAS-positive eosinophilic band is visible at the periphery of the aggregations. The latter feature is reminiscent of a cylindroma but the aggregates of cells are too large. Cylindroma-like features may be encountered in spiradenomas and sometimes these two entities occur together suggesting a common origin of these two adnexal neoplasms.

1. Argenziano G, Zalaudek I, Corona R, et al. Vascular structures in skin tumors: a dermoscopy study. Arch Dermatol. 2004;140(12):1485-9.   CrossRef