Sebaceous-like clear cell changes in primary lung cancer

Area of Science:

• Pulmonology
• Oncology
• Pathology

Background:

• Primary lung cancer diagnosis relies on precise histological classification.
• Identifying rare cell morphologies is crucial for accurate staging and treatment.

Observation:

• Two cases (0.7% of 281) of primary lung cancer with sebaceous-like clear cells (SLCCs) were identified.
• SLCCs were observed in advanced stage tumors (IIA and IIIA) admixed with conventional adenocarcinoma.
• These cells exhibited specific immunohistochemical markers, including EMA and CEA positivity, and TTF-1 focal positivity.

Findings:

• SLCCs demonstrated minimal mucin and no glycogen, ruling out typical glandular or squamous differentiation.
• Immunohistochemistry revealed diffuse EMA and CEA positivity, focal TTF-1 positivity, and negativity for Napsin A and GCDFP-15.
• Lipid was not detected in SLCCs via Oil red O staining or electron microscopy, excluding sebaceous differentiation.

Implications:

• SLCCs in lung cancer may represent dedifferentiation or non-specific changes in advanced adenocarcinoma.
• Distinguishing SLCCs from true sebaceous differentiation is essential for correct pathological diagnosis.
• Further research is needed to elucidate the origin and significance of SLCCs in lung adenocarcinoma.