Incidental Solitary Adrenal Metastasis as the Initial Manifestation of a Solid Variant of Papillary Thyroid Carcinoma, With Emphasis on Pathologic Diagnosis and Clinical Management

OBJECTIVE: Distant metastases from papillary thyroid carcinoma (PTC) are relatively rare and may be associated with a poor prognosis. The adrenal gland is a highly unusual site of metastasis in the natural course of PTC. Herein, we describe a case of an incidentally detected metastatic solid variant of PTC in the adrenal gland of an asymptomatic patient as the initial presentation. CASE REPORT: A 67-year-old male patient was evaluated for a 4.7-cm adrenal incidentaloma discovered during a workup for nephrolithiasis. Biochemical evaluation revealed a nonfunctioning adrenal mass. The patient underwent adrenalectomy, which revealed metastatic PTC. A subsequent thyroid ultrasound revealed an isthmic nodule. Fine needle aspiration of the nodule was cytologically suspicious for a follicular neoplasm, and gene expression analysis revealed an HRAS c.182A>G sequence variation. The patient subsequently underwent total thyroidectomy, which revealed a 1.2-cm solid variant of PTC in the thyroid isthmus. Postoperatively, the patient underwent radioactive iodine ablation. DISCUSSION: Our case illustrates an exceedingly rare and challenging situation—a metastatic solid variant of PTC in the adrenal gland of a patient with no prior history of PTC. When confronted with a PTC in the adrenal gland in the absence of a previously identified primary tumor, our experience suggests that the next step in management should be total thyroidectomy followed by radioactive iodine ablation. CONCLUSION: A solid variant of PTC is a rare cause of an incidentally detected adrenal lesion. Multidisciplinary care team coordination is essential for accurate diagnosis and treatment plan formulation.