Effusion-Dominant Pulmonary Sarcomatoid Carcinoma Without a Primary Mass: A Case Report

Area of Science:

• Oncology
• Pulmonology
• Pathology

Background:

• Sarcomatoid carcinoma is a rare and aggressive subtype of lung cancer.
• It typically manifests as a pulmonary or pleural mass.
• Effusion-dominant disease without a clear primary mass is exceptionally uncommon.

Purpose of the Study:

• To report a rare case of sarcomatoid carcinoma presenting as malignant pleural effusion without an identifiable primary mass.
• To highlight the diagnostic challenges and importance of early intervention in such cases.

Main Methods:

• Case report of a 59-year-old male with dyspnea, chest pain, and fever.
• Imaging revealed right pleural effusion without a lung mass.
• Diagnostic thoracoscopy identified necrotic pleural nodules, with histology confirming sarcomatoid carcinoma (cytokeratin AE1/AE3+, TTF-1 weak+, mesothelial markers-).

Main Results:

• The patient presented with effusion-dominant disease and no identifiable primary lung mass.
• Staging revealed contralateral lung nodules, mediastinal lymphadenopathy, and distant metastases.
• The patient opted for palliative care over systemic therapy.

Conclusions:

• Sarcomatoid carcinoma presenting as malignant pleural effusion without a mass is a rare clinical scenario.
• Early thoracoscopy and histological confirmation are crucial for diagnosis.
• Prognosis is poor, but emerging data suggest immunotherapy may have a role.