Thyroid Cancer and Acromegaly : A Case Report

Copyright: © 2016 Generoso JC, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. *Corresponding author: Thanh D Hoang, Department of Internal Medicine, Division of Endocrinology, Naval Medical Center, San Diego, CA, USA, Tel: 619-532-7375; E-mail: thanh.d.hoang.mil@mail.mil


Introduction
Acromegaly is a rare disease presentation in the general population.The relationship between thyroid cancer and acromegaly may seem rare however there is evidence showing a higher incidence of thyroid cancer in acromegalic patients.It would be important to consider the potential for thyroid disease in these patients.We present an interesting case of a man with history of thyroid cancer and a new diagnosis of acromegaly.

Discussion
Clinical features, biochemical testing, and imaging reveal a pituitary macro adenoma confirming a diagnosis of acromegaly.OGTT was not performed.Prolactin, luteinizing hormone, follicle stimulating hormone, cortisol, and thyroid function tests were normal.Patient underwent a transphenoidal hypophysectomy without complications.Pathology Keywords: Acromegaly; Papillary Thyroid Cancer; Clinical Vignette showed a plurihormonal adenoma with positive immunostaining for growth hormone in a significant number of cells, as well as diffuses staining for chromogranin and synatophysin (Figure 2).
Acromegaly is a rare disease caused by increased GH secretion and is associated with greater risk of developing both benign and malignant tumors.The clinical diagnosis is often delayed because of the slow progression of the acromegalic signs.Recent studies reveal an increase in cancer in patients with a known diagnosis of acromegaly which leads to the assumption that cancers are typically diagnosed later in these patients.Thyroid cancer is the most common malignancy diagnosed in acromegalic patients [1][2][3] and malignancies are the cause of death in 15% [2].Acromegaly is also known to be associated with diffuse and nodular goiters.Thyroid cells express the IGF-1 receptor and a TSH/IGF-1 interaction has been demonstrated to have a synergistic effect in thyroid cell growth.Recent studies havefound an increased prevalence of nontoxic nodular goiter and a slightly or moderately increased prevalence of thyroid carcinoma.The assumed pathogenesis in patients with acromegaly is that thyroid carcinoma develops following a sustained exposure to high serum IGF-1 levels [3].Open Access

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The fact that acromegaly appears to be a risk factor for developing malignancy may have led to improved surveillance for cancer in these patients.This case demonstrates that it is important to be aware of the association of various cancers, especially thyroid cancer, with acromegaly.

Disclaimer
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Figure 2 :
Figure 2: Pathology showed a plurihormonal adenoma with positive immunostaining for growth hormone in a significant number of cells, as well as diffuse staining for chromogranin and synatophysin.