Primary tumors of the lung other than lung cancer.

Neoplasms of the lung other than lung cancer are rare and have varying biologic behavior. Diffuse malignant mesothelioma remains a difficult clinical problem, with efforts directed at combined modality therapy. A nude mouse xenograft model may hold promise in the identification of active chemotherapy agents. Continuing evidence suggests that typical and atypical pulmonary carcinoids represent a spectrum of neuroendocrine disease, with small cell lung cancer representing the most virulent subtype. Therapy for advanced invasive thymoma includes neoadjuvant chemotherapy, surgery, and postoperative radiation. Nonseminomatous germ cell neoplasms of the mediastinum respond much less favorably to cisplatin-based chemotherapy than do similar tumors arising elsewhere, and new advances in treatment are needed. Rare mesenchymal tumors usually respond favorably to surgical excision.