Abstract #1400120: A Case Report of Papillary Thyroid Carcinoma with Thymic Metastasis

Papillary thyroid carcinomas (PTCA) are one of the most treatable cancers. Distant metastasis may occur, commonly to lungs and bones is often associated with poorer prognosis. Metastasis thymus extremely rare in any cancer has only been reported few case reports. We report a young Filipino patient presenting papillary carcinoma metastasizing thymus. This 32-year old female an incidental finding mediastinal mass palpable nodule. On neck ultrasound, multiple calcified nodules increased vascularity over right lobe pretracheal lymphadenopathies were visualized. Fine-needle biopsy was performed cytology suspicious for PTCA. Chest CT showed non-enhancing hypodense cystic while F18-FDG PET revealed hypermetabolic nodule non-hypermetabolic paratracheal mass. Total thyroidectomy excision histopathology showing PTCA perithyroidal thymic lymph nodes, left mediastinum. Radioactive iodine at dose 150 mCi subsequently administered, followed by post-therapy whole body scan no pathologic uptake. She then maintained on TSH-suppressive levothyroxine. six months follow-up, TSH thyroglobulin levels remained suppressed repeat ultrasound evidence recurrence. While generally favorable prognosis, certain risk factors have worse clinical outcomes including advanced age, presence distant extent size primary tumor. Age greatly affects prognosis among patients as mortality observed be higher aged 55 years above compared their younger counterparts. provided rationale current American Joint Committee Cancer (AJCC) staging system which applies age cut-off. In recent years, it also that would lead better outcome patients, still experienced poor survival those without metastasis. Among these male sex linked survival. Thymic considered However, due scarcity cases, long-term uncertain. Few cases malignancies surgery alone. Nevertheless, incidence recurrence radioactive therapy postoperatively our accordance Thyroid Association (ATA) guidelines recommendation led response. highlights importance individualized management.