Fine needle aspiration cytology in diagnosis of metastatic sebaceous gland carcinoma of the eyelid to the lymph nodes with clinicopathological correlation.

OBJECTIVE: The diagnosis of metastasis to the lymph node, especially with an inconspicuous primary lesion, poses a challenge to clinicians as well as to pathologists. We report the cytologic findings of sebaceous gland carcinoma (SGC) of the eyelid metastatic to the lymph node with confirmation by oil red O stain whenever required.

STUDY DESIGN: We reviewed cases and slides with cytologic diagnosis of metastatic SGC in lymph nodes.

RESULTS: Fifteen patients presented with metastasis to the preauricular (n = 15), submandibular (n = 6) and anterior cervical nodes (n = 3). The mean age was 56.4 years and the male:female ratio was 2:3. The upper lid was involved in 53.3% of cases. Fine needle aspiration cytology performed on the lymph nodes showed large polygonal cells with abundant vacuolated cytoplasm, numerous histiocytes and fat globules in the background. Oil red O staining was performed on air-dried smears in 7/15 cases and showed bright orange positivity in intracytoplasmic vacuoles and extracytoplasmic globules, confirming metastasis from SGC. Tissue was obtained from eyelid lesions for histopathologic diagnosis in 12 out of 15 cases. Out of 12 patients, 7 showed pagetoid spread at the primary site, with the tumor showing moderate differentiation in 6 cases.

CONCLUSION: Cytologic diagnosis of metastatic SGC is straightforward in most cases; however, use of oil red O stain supports the diagnosis, especially in cases with a silent primary tumor site.