THYROID MASS MASQUERADING AS LUNG CANCER

TOPIC: Lung Cancer TYPE: Medical Student/Resident Case Reports INTRODUCTION: Metastases to the thyroid gland are rare, accounting for only 1.3-3% of all malignancies, and they scarcely diagnosed before detection primary malignancy [1]. We present a case mass that led lung cancer. CASE PRESENTATION: A 57-year-old female with past medical history right adenoma status post lobectomy presented insidious growth firm, fixed on left side her neck in addition worsening fatigue, weakness, dysphonia, dysphagia, weight loss several months. On presentation, vital signs were unremarkable bloodwork revealed normal function. Physical exam was notable 3x3 cm round trachea without palpable lymphadenopathy. Thyroid ultrasound new large suspicious nodule aspect isthmus 2 smaller nodules lobe. With concern malignancy, computed tomography (CT) chest obtained, which noted malignant occupying hemithorax invasion into mediastinum atrium. In addition, lobe up 3.6 metastatic lesions breast adrenal noted. biopsy poorly differentiated non-small cell carcinoma, favoring primary, tumor cells positive AE1/AE3, cytokeratin 7 (CK7) negative CK20, transcription factor-1, (TTF-1), thyroglobulin. Chemoimmunotherapy started paclitaxel, carboplatin, pembrolizumab, an excellent response; repeat imaging has shown marked decrease metastases. The size also decreased, resulting clinical improvement symptoms. DISCUSSION: Metastatic spread is usually, patients asymptomatic, metastases found during diagnostic workup malignancy. Rarely have been initial manifestation, leading cancer diagnosis usually based histopathology immunohistochemistry, cytology having low yield. Differentiating between versus focus from often challenging, as lungs common embryogenesis similar immunohistochemical staining. Staining TTF-1 thyroglobulin point away would help guide treatment [2]. CONCLUSIONS: Despite rarity lesions, any appearance should be considered potentially metastatic, thorough rule out REFERENCE #1: Chung AY, Tran TB, Brumund KT, et al. thyroid: review literature last decade. Thyroid. 2012;22(3):258-268. #2: Ciobanu D, Vulpoi C, Găluşcă B, value secondary tumors gland. Rom J Morphol Embryol 2007,48(2):113–119. DISCLOSURES: No relevant relationships by Kasopefoluwa Akinbamijo, source=Web Response Keerthy Joseph, Sudheer Konduru, Rajesh Thirumaran, Vihitha Thota, Manaswitha