An Unusual Case of Papillary Thyroid Carcinoma Iodine-131 Avid Metastasis to the Adrenal Gland

Abstract

SUMMARY – Papillary thyroid carcinoma (PTC) is considered one of the most favorable tumors, indolent, with rare distant dissemination. Lungs and bones are the most common metastatic sites. Unusual sites of PTC distant metastases are extremely rare. Brain, liver, skin, kidney, pancreas, and adrenal gland PTC metastases have been sporadically reported in the literature. An 86-year-old female patient underwent total thyroidectomy and neck dissection due to PTC. Postoperative whole body iodine-131 scintigraphy with I-131 SPECT/CT of the abdomen revealed radioiodne avid left adrenal gland metastasis together with high postoperative serum thyroglobulin (Tg) value of more than 5000 µg/L and high serum Tg antibodies. Considering the above-mentioned findings, patient‘s age and multiple comorbidities, radioiodine therapy was applied. PTC metastases to the adrenal gland are extremely rare, and to our knowledge, only nine cases have been reported in the literature. This case report complements rare examples of unusual PTC metastases.

Isolated adrenal metastases of papillary thyroid carcinoma

“…AMs account for approximately 1.7% of DTC distant metastases and are mostly associated with the presence of other distant metastases [3]. To our knowledge there were only 4 reported cases of isolated AMs from PTC [1,2,4,5] . Our case is unique because AMs occurred after a significant period of complete remission.…”

“…To our knowledge, there have been very few reported cases of PTC with metastatic spread only to the adrenal gland [1,2,4,5]. None of these cases achieved remission previously to the diagnosis of AMs.…”

Papillary thyroid carcinoma presenting as metastases at unexpected sites: Report of two cases

“…Rare distant metastatic locations of PTC that have been sporadically reported include the following: liver, pancreas, spleen, kidney, adrenal gland, brain, cerebellum, skeletal muscle, parotid gland, skin, and so on. [5][6][7][8][9][10][11][12][13][14] Less than 1/2,000 thyroid tumours initally manifest as adrenal metastasis [15] and they are usually multiple, bilateral and often associated with lung or bone metastases. [16,17] In our case, metastasis was solitary and unilateral in the left adrenal gland without evidence of involvement of other common locations like lung or bone.…”

Skin metastasis as incidental finding in follicular epithelium derived – thyroid cancer

“…The sentinel node is located within central compartment (levels VI and VII); the second station is lateral compartment (levels II, III, IV, and V) followed by contralateral neck region (6). The rarest secondary sites of thyroid cancer involvement that have been cited are at mammary level, renal area as well as pancreas, adrenals, cerebral, ovarian, parotids, and teguments (11,12,13). Cutaneous location varies from neck and head (majority) to exceptional sites as chest wall and of variable incidence for scalp (11,12,14,15).…”