A 2 cm peripheral squamous cell carcinoma in the lung of a 60-year-old male with a pleural effusion positive for malignant cells would be classified as:

d. T4N0M0

e. T4N0M1

The presence of a pleural effusion in association with a primary lung cancer is usually an ominous sign precluding surgical resection. However, if more than one sample of the effusion is negative for malignant cells and it is non-bloody, it can be considered unrelated to the tumor and excluded as a staging element. When the effusion cytology is positive, the tumor is considered T4 regardless of size or nodal status.