Pulmonary adenocarcinoma with signet-ring cell features shows malignant cells with a large cytoplasmic vacuole that displaces the nucleus to the periphery, creating a 'signet-ring' appearance. The vacuole often contains mucin (PAS-positive, mucicarmine-positive). These cells may be isolated or in clusters. Primary pulmonary signet-ring adenocarcinoma is rare and aggressive, often associated with younger patients and smoking. It must be distinguished from metastatic signet-ring carcinoma (especially from stomach or breast) and other mucinous lung tumors. Immunohistochemistry (TTF-1, napsin A may be positive) and clinical history help determine primary site.

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Zambia

• Joseph Soko – 101 pts

• Visual Pathway Lesions
• Positive and Negative Symptoms
• Hallucinations and Delusions
• Antipsychotic Medications
• Emergency: Environmental Emergencies