Key message
The differential diagnosis between sebaceoma and basal cell carcinoma could present some difficulties because both types of lesions
An 81-year-old man presented for a routine clinical dermatologic examination. The examination revealed a 15-mm, pink, well demarcated nodule on the sacral region (Fig 1).
Dermoscopy revealed a lesion with a homogeneous, translucent yellow-pinkish area, with some ulcerations in the middle and arborizing telangiectasias starting from the periphery that ramify towards the center of the lesion (Fig 2), suggestive of rippled pattern sebaceoma.1
To better discriminate the nature of this lesion, a 22-MHz high-frequency ultrasound (HFUS) examination was performed. HFUS revealed a very superficial, hyporeflective, well delimited oval structure (Fig 3), characterized by a homogeneous echo-poor area compared with the surrounding tissues.
The histopathologic examination revealed a multinodular tumor with symmetric, well circumscribed lobules in the dermis, partially connected to the epidermis (Fig 4). Lobules were composed of basaloid cells without nuclear atypia or mitotic figures, mixed with sebocytes and sebaceous duct–like structures. Focally, the tumor had a peculiar rippled pattern.2 The differential diagnosis between sebaceoma and basal cell carcinoma could present some difficulties because both types of lesions Key message
Although there are usually other differences in the silhouette of both tumors (sebaceous adenoma usually connects to the epidermis, whereas sebaceoma do not), there are many cases of benign sebaceous neoplasms with overlapping cytologic and architectural features, suggesting a possible morphologic spectrum.12–17 Dermoscopically, differentiating between sebaceous adenoma and sebaceoma is not achievable and 2 main patterns have been described in both lesions.12–17 First, tumors with a central crater are dermoscopically characterized by elongated radial telangiectasias (crown vessels) that embrace an opaque structureless ovoid white-yellow center, which are at times covered by blood crusts.13
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Conflicts of interest: None declared.