A Case of Hypothyroid Graves' Disease Following External Radiation Therapy to the Cervical Region

• Published in: ENDOCRINE JOURNAL Vol. 53; no. 3; pp. 357 - 361
• Main Authors: NISHIHARA, Eijun, FUKATA, Shuji, KIMURA, Nobuhiko, HAGIHARA, Masahiro, KUDO, Takumi, OHYE, Hidemi, ITO, Mitsuru, KUBOTA, Sumihisa, AMINO, Nobuyuki, KUMA, Kanji, MIYAUCHI, Akira
• Format: Journal Article
• Language: English; Japanese
• Published: Japan The Japan Endocrine Society 2006
• Subjects: Carcinoma, Squamous Cell - radiotherapy; Diplopia - diagnostic imaging; Diplopia - etiology; External radiation therapy; Graves Disease - diagnosis; Graves Disease - etiology; Graves Ophthalmopathy - etiology; Graves' ophthalmopathy; Humans; Hypothyroid Graves' disease; Hypothyroidism - diagnosis; Hypothyroidism - etiology; Male; Middle Aged; Radiation Injuries - etiology; Radiotherapy - adverse effects; Submandibular Gland Neoplasms - radiotherapy; TBII; TSAb; Ultrasonography
• ISSN: 0918-8959; 1348-4540
• DOI: 10.1507/endocrj.K05-117

A case of hypothyroid Graves' disease occurred following external radiation therapy to the cervical region is described. Severe hypothyroidism developed in a 56-year-old man 6 months after external radiation therapy for submandibular cancer. Serological evaluation of thyroid autoimmunity revealed the presence of antithyroid antibodies and thyrotropin-binding inhibitory immunogloblins (TBII). Diplopia, limitation of downward gaze, and palpebral edema developed 2 years after levothyroxine replacement therapy. Ocular magnetic resonance imaging revealed marked hypertrophy of the bilateral extraocular muscles with signal hyperintensity on T2-weighted images. This infiltrative ophthalmopathy showed marked improvement after additional treatment with high-dose methylprednisolone and orbital radiation, in parallel with a decrease in TBII. These results suggest that radiation-associated thyroidal injury might be associated with the etiology of hypothyroid Graves' disease.