Cytodiagnostic Dilemma in a Lung Mass as the First Presentation of Testicular Mixed Germ Cell Tumor Metastasis.

Testicular mixed germ cell tumors (TMGCTs) are rare malignant tumors comprising of two or more types of germ cell tumors. Their onset may be undetectable and the patient may first present with symptoms of metastasis. We hereby report a case of a young male who presented with respiratory discomfort and had no symptoms of primary testicular tumor. CT-guided FNAC lung revealed mainly necrotic, keratinous debris with a focus of chondromyxoid stroma. Differential diagnoses of components of teratoma, squamous cell carcinoma and inclusion cyst was considered. FNAC was reported out for the possible presence of teratoma components. Retrospectively, physical examination and subsequent USG revealed testicular tumor. The case led to a diagnostic dilemma as the patient presented with no prior history suggestive of metastasis from testicular mixed germ cell tumor. The aim of the current case report is to alert the pathologists and clinicians about this uncommon clinical presentation and diagnostic relevance of FNA. It highlights that FNA lung revealing keratinous material should always be searched for the possibility of teratoma component.