Presentation of Pheochromocytoma, Papillary Thyroid Cancer and Hyperparathyroidism in Three Family Members

Abstract

Abstract Introduction: Although rare, one of the most common inherited disorders is multiple endocrine neoplasia. It is an autosomal dominant disorder that predisposes individuals to certain endocrine abnormalities depending on which type. The type 2A is a combination of medullary thyroid cancer, hyperparathyroidism, and pheochromocytoma which have been explained to be due to a mutation in the RET proto-oncogene. This abstract present a case of a patient with hyperparathyroidism whom family members also have pheochromocytoma and papillary thyroid cancer. Case description: A 45 year-old Hispanic male came to the endocrinology clinic complaining of constipation and headache. He has a personal history of non-toxic multinodular goiter and underwent right sided thyroidectomy in 2015 with pathology report showing follicular adenoma. He is currently on thyroid replacement therapy. He is clinically and biochemically euthyroid with TSH of 2.29 IU/ml. Physical examination was unremarkable. His labs were pertinent for calcium 11.5mg/dl, parathyroid 245.7pg/ml, creatinine of 1.5mg/dl. Two years ago, parathyroid was 189.5pg/ml and calcium was 11mg/dl, 1.5 year ago parathyroid level was 235.5pg/ml, calcium was 11.4mg/dl, urine calcium 9.3mg/dl, 24hr urine calcium 286.4mg, calcitonin <2pg/ml, vitamin D 23ng/ml, 1,25 vitamin D 53ng/ml. In 2017, Sestambi scan showed equivocal focus of faint parathyroid activity in the region of the mid to lower left thyroid lobe versus faint residual thyroid activity and in 2019, scan showed no definite parathyroid adenoma. Surgical intervention was recently recommended due to patient’s DEXA scan showing osteoporosis of the femoral neck. The family history of this patient is pertinent for two sisters; one with pheochromocytoma and the other with papillary thyroid cancer. One of the sisters is a 60 years old diagnosed with pheochromocytoma at 51. Her free normetanephrine level was 682pg/ml and total metanephrine was 727pg/ml at time of diagnosis. Her MRI report showed right adrenal mass measuring 3.5x2.8cm. Laparoscopic right adrenalectomy was done and pathology confirmed pheochromocytoma which was RET negative. She still follows up with endocrinology and calcitonin, chromogranin A and plasma metanephrines have been normal. The second sister is now 53 years old diagnosed with papillary thyroid cancer at age 27 and had total thyroidectomy with pathology confirming papillary thyroid cancer. Discussion: Based on the clinical presentation of these family members, the most likely explanation is familial inheritance. This pattern of inheritance cannot be explained by MEN 2A or 2B due to the absence of medullary thyroid cancer. It has also been reported that this unusual presentation could be a variant of MEN 2A.[i] Due to the family history, close follow up is required to monitor for the possible development of other endocrinopathies in the future.