SUN-612 Pleural Effusions Revealing Anaplastic Dedifferentiation of Papillary Thyroid Carcinoma

Anaplastic dedifferentiation of papillary thyroid carcinoma to lung, pleura and lymph nodes is rare, rapidly progressive and fatal. We report a case of a firefighter who survived the World Trade Center collapse presenting with a large thyroid mass, worsening pleural effusions and pulmonary nodules. A 49-year-old male with history of diabetes and hypertension presented to the Emergency Department with several days of shortness of breath. Vitals were significant for hypoxia, tachypnea and tachycardia. CT Angiography revealed a large (5 x 7 cm) necrotic mass with direct extension to the mediastinum with multiple metastatic lymph nodes in the hila and lungs with bilateral pleural effusions. Dyspnea was relieved in the Emergency Department with placement of a pigtail catheter and pleural fluid was sent for cytology. Further history from family revealed the patient had worked as a firefighter at the World Trade Center for four months. After September 11(th), he followed in the WTC survivor clinic in Manhattan with chest x-rays twice a year, the last of which had no abnormalities. Family also reported months of worsening dyspnea with a “high-pitched voice”, weakness and a 20-pound weight loss. Social history was significant for active tobacco use of a pack-per-day for ten years. In the Emergency Department, the patient was placed on supplemental oxygen and otolaryngology performed nasopharyngolaryngoscopy that showed right vocal cord immobility and mild tracheal compression. High-dose dexamethasone taper was initiated. In the hospital, the patient’s respiratory status worsened and he became increasingly septic. Antibiotics were begun for presumed pneumonia. Due to worsening hypercapnea and tracheal compression, the decision was made with family to intubate and vasopressors were begun for hypotension. Interventional radiology performed a biopsy of the thyroid mass revealing papillary carcinoma, but lung nodule biopsy was unrevealing. Subsequent pleural fluid analysis showed poorly differentiated malignant cells with a high degree of nuclear pleomorphism and bizarre shapes suggestive of anaplastic features. Immunohistochemistry was positive for Paired Box Gene 8 (PAX8) and Cytokeratin 7 (CK7). As PAX8 is specific for thyroid cancer, the pleural effusions were thought to be metastatic adenocarcinoma from anaplastic dedifferentiation of papillary thyroid cancer. Given clinical status, the patient was not a candidate for chemotherapy. A goals-of-care decision was made to focus on comfort and the patient passed comfortably with family at bedside. Anaplastic thyroid tumors account for less than two-percent of all thyroid cancers. However, they are rapidly progressive and fatal with tumor burden often doubling in under a week’s time. Identifying these tumors earlier remains a goal in reducing the rate of anaplastic tumors in patients with carcinogenic exposure, such as our patient.