Grave's disease induced by radiotherapy for nasopharyngeal carcinoma: A case report and review of the literature

Radiation-induced inflammation and autoimmune diseases

Currently, ionizing radiation (IR) plays a key role in the agricultural and medical industry, while accidental exposure resulting from leakage of radioactive sources or radiological terrorism is a serious concern. Exposure to IR has various detrimental effects on normal tissues. Although an increased risk of carcinogenesis is the best-known long-term consequence of IR, evidence has shown that other diseases, particularly diseases related to inflammation, are common disorders among irradiated people. Autoimmune disorders are among the various types of immune diseases that have been investigated among exposed people. Thyroid diseases and diabetes are two autoimmune diseases potentially induced by IR. However, the precise mechanisms of IR-induced thyroid diseases and diabetes remain to be elucidated, and several studies have shown that chronic increased levels of inflammatory cytokines after exposure play a pivotal role. Thus, cytokines, including interleukin-1(IL-1), tumor necrosis factor (TNF-α) and interferon gamma (IFN-γ), play a key role in chronic oxidative damage following exposure to IR. Additionally, these cytokines change the secretion of insulin and thyroid-stimulating hormone(TSH). It is likely that the management of inflammation and oxidative damage is one of the best strategies for the amelioration of these diseases after a radiological or nuclear disaster. In the present study, we reviewed the evidence of radiation-induced diabetes and thyroid diseases, as well as the potential roles of inflammatory responses. In addition, we proposed that the mitigation of inflammatory and oxidative damage markers after exposure to IR may reduce the incidence of these diseases among individuals exposed to radiation.

Prolactin-Producing Pituitary Carcinoma, Hypopituitarism, and Graves' Disease-Report of a Challenging Case and Literature Review

INTRODUCTION

The diagnosis of pituitary carcinoma is very rare, requires the evidence of metastatic disease, and has a poor overall survival. Malignant prolactinoma frequently requires dopamine agonist therapy, pituitary surgery, radiotherapy, and even chemotherapy.

CASE DESCRIPTION

A 19-year-old female presented with galactorrhea, primary amenorrhea, and left hemianopsia. Complementary study detected hyperprolactinemia and a pituitary macroadenoma with cavernous sinus invasion and suprasellar growth. She was treated with cabergoline and bromocriptine without clinical or analytical improvement. Resection of the pituitary lesion was programmed and a non-contiguous lesion of the nasal mucosa was detected during the approach. This metastasis led to the diagnosis of prolactin-producing pituitary carcinoma. After partial resection, the patient was submitted to radiotherapy for residual disease with persistent symptoms. She developed growth hormone deficiency, central hypothyroidism, hypogonadism, and permanent diabetes insipidus. Six years later she was admitted for the suspicion of secondary adrenal insufficiency and thyrotoxicosis. Physical findings, laboratory data, thyroid ultrasound, and scintigraphy achieved the diagnosis of Graves' disease and hypocortisolism. She was treated with hydrocortisone and methimazole, but central hypothyroidism recurred after antithyroid drug withdrawal. Nine years after the diagnosis of a pituitary carcinoma, she maintains treatment with bromocriptine, has a locally stable disease, with no metastases.

CONCLUSION

This report highlights an unusual presentation of a prolactin-producing pituitary carcinoma in a young female. The patient had multiple hormone deficiencies due to a pituitary lesion and treatments. The posterior development of hyperthyroidism and adrenal insufficiency brought an additional difficulty to the approach.

Thyroid hormones alter estrous cyclicity and antioxidative status in the ovaries of rats

To expand our understanding of the roles of thyroid hormones on female reproduction, we induced hypo- and hyper-T rat models to investigate the roles of thyroid hormones on estrous cyclicity, as well as the antioxidative status in the ovaries of rats. In the current study, our data show that hypothyroidism (hypo-T) and hyperthyroidism (hyper-T) led to significantly reduced body weights and ovarain weights and delayed vaginal opening day. For hyper-T, thyroxine (T4), tri-iodothyronine (T3), progesterone (P4) and follicle-stimulating hormone (FSH) were significantly increased, while estradiol (E2) and luteinizing hormone (LH) were significantly decreased. For hypo-T rats, serum levels of total T4 and T3, E2, P4, FSH and LH were significantly increased, while concentrations of E2 and LH were significantly decreased. For ovary morphology, the numbers of secondary and antral follicles were significantly decreased with more atretic antral follicles and less corpora lutea in both hyper- and hypo-T groups. Both hyper-T and hypo-T treatment significantly decreased the expressions of thyroid hormone receptor α1 in the ovary. Hypo-T significantly reduced nitric oxide (NO), total NO synthase (tNOS), inducible NOS and constitutive NOS activities, but hyper-T increased them. For antioxidative parameters, hypo-T and hyper-T treatment significantly increased malondialdehyde (MDA) contents. The activities of both glutathione peroxidase (GSH-Px) and catalase (CAT) significantly decreased in the hypo-T group but increased in the hyper-T group. Total superoxide dismutase (T-SOD) activity was significantly increased in the hyper-T group. In summary, thyroid hormones alter estrous cyclicity and antioxidative status in the ovary of the rat may act through the NOS signaling pathway.