Grennan, Krista

Abstract Disclosure: A.L. McKenna: None. S. Thota-Kammili: None. K. Grennan: None. S. Rao: None. It is known that thyroid dysfunction is an adverse effect of tyrosine kinase inhibitors (TKIs) via inhibition of the vascular endothelial growth factor receptor (VEGFR). The VEGF signaling pathway is important in regulating angiogenesis in tumors and normal tissue. As a highly vascularized gland, it is expected the thyroid may be compromised because of VEGFR inhibitors. Proposed mechanisms of thyroid dysfunction include capillary regression and constriction leading to reduced vascular perfusion to the gland. Bevacizumab is a monoclonal antibody that targets VEGF and inhibits activation of VEGFR, reducing angiogenesis; interestingly, this is not commonly reported in the literature. Here we present a case where bevacizumab altered thyroid function in a patient with pre-existing primary hypothyroidism. A 60-year-old woman presented with worsening hypothyroidism. She reported a history of nonautoimmune primary hypothyroidism diagnosed in her early 20s; she still had an intact thyroid with no history of head/neck radiation. In the months leading to the presentation, she had been receiving maintenance chemotherapy with 5 fluorouracil and bevacizumab every 2 weeks for metastatic duodenal carcinoma. Prior to starting chemotherapy, she had been on a steady dose of 112 mcg of levothyroxine (LT4) daily. After 6 months on chemotherapy, she reported symptoms of fatigue and hair loss. Workup revealed an elevated TSH of 41 mIU/L (reference 0.3-4.2 mIU/L). She denied any significant changes in weight or malabsorption issues. Aside from the chemotherapy, no other new medications were introduced. Her LT4 dose was increased to 137 mcg daily, and 3 months later, there was improvement in TSH to 6.5 mIU/L as well as her symptoms. At this point, bevacizumab was briefly on hold for 2 months due to an upcoming procedure, hence there was no change to LT4 to avoid over correction. Her TSH normalized and was trending lower while bevacizumab was on hold. Once bevacizumab resumed, LT4 was preemptively increased to 150 mcg daily. Four months after resuming bevacizumab, her TSH remains within the normal reference range on 150 mcg LT4. It is hypothesized that this VEGF blocker led to worsening of her underlying hypothyroidism.Given the shared down regulation in the VEGF signaling pathway, it would be expected that TKIs and monoclonal antibodies against VEGF would share similar adverse reactions to the thyroid. However, to our knowledge, there have been limited reports of bevacizumab induced thyroid dysfunction in the literature. Explanations to this may include the more targeted VEGF inhibition with bevacizumab versus the inhibition of multiple kinase receptors from the TKIs. Further research into this will be needed. This case demonstrates that bevacizumab can impact thyroid function and thyroid labs may need to be monitored at the onset and during VEGF inhibitor therapies. Presentation: 6/3/2024

Abstract Disclosure: K.N. Grennan: None. S. Thota-Kammili: None. A.L. McKenna: None. C.G. Coyle: None. S.L. Samson: None. Introduction: Supplement misuse in the bodybuilding community is prevalent. With the availability of internet ordering and purchasing, patients have access to hormonal supplements without prescription or regulation. Here we present the case of a patient on self-administered hormonal supplements who presented in acute heart failure leading to cardiogenic shock in the setting of concurrent thyroid, adrenal, and gonadal axis dysfunction. Case Description: A 28-year-old male with no significant medical history was transferred to our hospital after presenting to an outside emergency room with dyspnea, cough, nausea, and a subjective fever. He developed acute hypoxic respiratory failure requiring intubation. Echocardiogram performed showed an ejection fraction (EF) of 10%. He was started on two vasopressors and methylprednisolone 1 g daily for two days, due to concern for myocarditis versus giant cell arteritis. Hormonal work-up showed TSH 0.02 mIU/L (normal range 0.3-4.2), free T4 0.4 ng/dL (0.9-1.7), total T3 48 ng/dL (80-200), FSH <0.3 IU/L (1.2-15.8), LH <0.2 IU/L (1.3-9.6), ACTH <5.0 pg/mL (7.2-63), cortisol 1.7 mcg/dL (2.5-12), estradiol 171 pg/mL (8.0-35), total testosterone 1730 ng/dL (240-950), and prolactin 47 ng/mL (4.0-15.2). He received 10 mg dexamethasone at the outside facility. A medication bag found by his family included online purchases of non-prescribed testosterone cypionate and enanthate, liothyronine, anastrozole, and clomiphene. None were medical grade. He was also taking the anabolic steroid clenbuterol for 3 days prior. Echocardiogram on day 3 of admission showed an improved EF of 36%. Cardiac magnetic resonance imaging (MRI) showed a papillary fibroelastoma and myocarditis. Patient was weaned off vasopressors and the ventilator. He was discharged on levothyroxine 50 mcg daily and hydrocortisone 10 mg twice daily for outpatient reassessment. Transesophageal echocardiogram confirmed diagnosis of papillary fibroelastoma. One month Endocrinology clinic follow-up showed no evidence of posterior pituitary, thyroid, or adrenal axis dysfunction or growth hormone excess, but he continued to have gonadal axis suppression with elevated prolactin and estradiol, the latter thought to be secondary to conversion from testosterone. Pituitary MRI showed no micro or macroadenoma. His EF recovered to 50%. He is pending surgical removal of the aortic valve fibroelastoma. Discussion: With hormonal supplements easily accessible online, it is important for physicians to counsel patients about the dangers of misuse. This case highlights a previously healthy 28-year-old man who presented in critical condition with cardiogenic shock and hypothalamic-pituitary axis dysfunction from supplements he purchased online. There should be targeted educational interventions regarding the harm of supplements aimed at the bodybuilding community to prevent similar cases. Presentation: 6/2/2024

Abstract Disclosure: A.Y. Chang: None. D.Z. Erickson: None. W.F. Young: None. K. Grennan: None. J.C. Andrews: None. E. Kapoor: None. Background: While mild androgen excess is frequently encountered in endocrine practices, severe symptoms, rapid onset or markedly abnormal biochemical testing lead to further evaluation for rare ovarian androgen-producing tumors, ovarian hyperthecosis or androgen-secreting adrenal tumors. Combined ovarian and adrenal vein sampling (COAVS) might be necessary to identify the source of androgen hypersecretion and guide treatment. The utility of COAVS has been studied in limited case series, combining case reports and different centers. There is no consensus regarding the testosterone gradient that localizes the androgen source or the added value of COAVS when a pathologic source of androgen excess is suspected. The additional clinical benefit of adrenal vein sampling (AVS) when combined with ovarian vein sampling (OVS) has also not been examined. Objectives: We sought to determine: a) the optimal total testosterone (TT) gradient for identifying unilateral vs bilateral source of hyperandrogenism and b) the utility of AVS in addition to OVS. Methods: We performed a retrospective chart review of all adult women who had COAVS at Mayo Clinic, Rochester from 1996 to 2023. Pathologic sources of androgen excess were defined as ovarian hyperthecosis (OH) as well as ovarian and adrenal tumors. We calculated the ratio of dominant OV or AV divided by the nondominant OV or AV. Results: 22 COAVS procedures from 7 premenopausal and 15 postmenopausal women were included in the study: 12 (55%) women had adrenal abnormalities seen on computed cross sectional imaging and 5 (23%) had unilateral ovarian imaging abnormalities. Of the 22 participants in the case series, successful 4-vessel catheterization was completed in 20 (1 right ovarian vein could not be cannulated, and 1 had bilateral oophorectomy). Nine (41%) women had unilateral and 10 (45%) bilateral ovarian androgen hypersecretion. Eleven (50%) women had pathologic causes for elevated TT (5 ovarian tumors, 6 cases of OH), 5 lacked follow-up pathology and 5 had benign pathology. AVS did not diagnose an adrenal source of androgen hypersecretion. TT concentrations were significantly greater in patients with unilateral compared to those with bilateral ovarian androgen hypersecretion (median 262.5 ng/dL [245- 401.5 IQR] vs 104 ng/dL [82-190], P = 0.01). In addition, TT concentrations were higher in those women with a pathologic source of TT hypersecretion compared to those with benign ovaries (349 ng/dL [251-538] vs 115 ng/dL [93-195], P = 0.03). All cases of unilateral ovarian disease had a dominant OV gradient of TT ≥ 2.1 compared to the nondominant OV. Conclusion: In a series of successful COAVS in women with androgen hypersecretion, an ovarian side-to-side gradient of ≥ 2.1 diagnosed all sources of unilateral ovarian pathology. AVS did not diagnose any pathologic source of adrenal androgen excess in this patient cohort. Presentation: 6/3/2024