Specific Tumor Structures and Features Differentiate Sebaceous Carcinoma

Common features of sebaceous carcinoma include a polymorphic vessel pattern yellow structures as well as various whiteish-pink areas, and the yellowish structures (among other features) may help differentiate sebaceous carcinoma from both squamous cell carcinoma (SCC) and basal cell carcinoma (BCC). This is according to study research published in the Journal of Dermatology.

A total of 15 patients (mean age, 73.13±15.29 years [range, 43-103]) with histologically diagnosed sebaceous carcinoma who had dermoscopic examinations performed at a hospital in Taiwan were included in this retrospective study. In the overall cohort, patients had sebaceous carcinomas, sebaceous hyperplasia, sebaceoma, squamous cell carcinoma, and basal cell carcinoma.

The sebaceous carcinoma cases presented with erythematous-to-yellowish nodules or plaques featuring a mean size of 11.87±6.48 mm (range, 5–25). In 10 cases (66.67%), patients had poorly differentiated type SC. More than half (53.33%) of infiltrative cell growth types featured basaloid cells.

A polymorphic vessel pattern was observed in 66.67% of tumors, whereas the other tumors demonstrated a monomorphic vessel pattern. The most common vascular arrangements were nonspecific (46.67%) and radial (40%). The most common vessel type was linear-irregular (73.33%) followed by arborizing (46.67%), hairpin (26.67%), milky red (26.67%), serpentine (13.33%), dotted (6.67%) and coiled (6.67%).

In addition, the investigators observed whitish-pink areas (80%), yellowish structures (73.33%), ulceration (46.67%), shiny white blotches and strands (46.67%), white structureless area (33.33%), and purplish globules (33.33%).

Sebaceous carcinoma was significantly associated with purplish globules (P =.042), shiny white blotches and strands (P <.05), and whitish-pink area (P <.05) compared with other sebaceous tumors. Features more prevalent in sebaceous carcinoma were associated with polymorphous vascular pattern (P <.001), yellowish structureless area (P <.001), white structureless areas (P =.042), and ulceration (P =.035). Sebaceous hyperplasia was associated with crown (P <.001) and yellowish globules (P <.001).

Compared with BCC, sebaceous carcinoma was associated with more linear-irregular vessels (P =.027), white structureless areas (P =.042), whitish-pink area (P =.025), yellowish structure (P <.001), and yellowish structureless areas (P =.002). Features significantly associated with BCC included spoke wheel areas (P =.017), leaf-like areas (P =.006), blue-gray ovoid nest (P <.001), and blue-gray dots/nests (P < 0.001). Yellowish structures (P < 0.001) and yellowish structureless areas (P < 0.001) were associated with SC more than SCC.

Limitations of this study included the small number of patients as well as the inclusion of only extraocular cases of sebaceous carcinoma.

According to the investigators, the findings that purplish globules, shiny white blotches and strands, and whitish-pink area were significantly associated with sebaceous carcinoma “indicated that intratumoral hemorrhage and stromal fibrosis were more common in cases of sebaceous carcinoma histopathologically.”

Reference

Cheng CY, Su HJ, Kuo TT. Dermoscopic features and differential diagnosis of sebaceous carcinoma [published online May 16, 2020]. J Dermatol. doi: 10.1111/1346-8138.15384