Recurrent Acromegaly in a Patient With a CHEK2 Mutation

BACKGROUND/OBJECTIVE: CHEK2 is a cell-cycle checkpoint kinase and is part of the ATM-CHEK2-p53 cascade, which is protective against carcinogenesis. We describe a germline CHEK2 mutation in a patient with acromegaly and other tumors. CASE REPORT: We present a woman with a germline CHEK2∗ 110delC mutation previously diagnosed with fibroadenoma of the breast and papillary thyroid carcinoma. She presented with acromegaly at age 48 (insulin-like growth factor 1, 556 mcg/L [reference range, 90-360] and lack of growth hormone suppression on glucose tolerance testing) and underwent transsphenoidal resection of a somatotroph microadenoma. Four years after surgery, she developed recurrent growth hormone excess. She was treated with cabergoline, which was discontinued due to intolerance, and transitioned to lanreotide depot, which was switched to pegvisomant because of prediabetes. Her insulin-like growth factor 1 levels remained normal on pegvisomant. Follow-up magnetic resonance imaging examinations showed no evidence of tumor progression. Shortly after the diagnosis of acromegaly, the patient was diagnosed with endometrial carcinoma, bilateral ovarian cystadenomas, and uterine leiomyomas. She was additionally found to have a nonfunctioning adrenal nodule and hyperplastic and adenomatous colon polyps. There are multiple family members with malignancies, including colon, thyroid, and lung cancer. DISCUSSION: This is a novel report of a patient with a pathogenic germline CHEK2 mutation and multiple malignant and benign tumors, including recurrent acromegaly. CONCLUSION: Our data raise the possibility that CHEK2 mutations may be involved in the development of acromegaly. Additional studies are needed to elucidate the potential role of CHEK2 mutations in the pathogenesis of somatotroph adenomas.