Two histopathologic patterns of well-differentiated extraocular sebaceous carcinoma

Area of Science:

• Dermatopathology
• Oncology

Background:

• Limited published data exists on variations in well-differentiated sebaceous carcinoma histopathology.
• Sebaceous carcinoma is a rare malignant neoplasm originating from sebaceous glands.

Purpose of the Study:

• To describe and differentiate the histopathological patterns of well-differentiated extraocular sebaceous carcinoma.
• To investigate potential differences in cytological atypia and associated features between identified patterns.

Main Methods:

• Retrospective review of histopathology from six cases of well-differentiated extraocular sebaceous carcinoma.
• Classification of cases into distinct histopathological patterns based on architectural and cytological features.

Main Results:

• Two patterns were identified: secretory (N=2) characterized by lobular architecture and focal holocrine secretion, and non-secretory (N=4) lacking organoid quality.
• Secretory pattern cases showed low-grade atypia, while non-secretory cases had predominantly high-grade atypia.
• Sebaceous adenoma-like areas were present in secretory pattern tumors, whereas sebaceous carcinoma in situ was observed in two non-secretory pattern tumors.

Conclusions:

• Two distinct histopathological patterns of well-differentiated sebaceous carcinoma were defined: secretory and non-secretory.
• The clinicopathological significance and prognostic implications of these patterns require further investigation in larger cohorts.
• Additional studies are necessary to elucidate the histogenetic differences and clinical relevance of these sebaceous carcinoma subtypes.