Endocrine Abstracts

JOINT2296

Background: Pseudohypoparathyroidism (PHP) is a rare inherited disorder characterized by hypocalcemia and hyperphosphatemia due to end organ resistance to parathyroid hormone. This disorder is caused by mutations at the complex GNAS locus on chromosome 20 q13.3. The GNAS encodes alpha subunit of G protein stimulating the activity of adenylate cyclase, which is controlling the production of several hormones from different endocrine glands, such as: the thyroid, pituitary, ovaries, and testes. Ovarian teratomas are benign neoplasms that arise from pluripotent germ cells that differentiate into various tissues, including endocrine-related structures. Since GNAS mutations impact various tissues derived from the mesoderm and ectoderm, there could be a theoretical developmental link.

Case presentation: We present a rare case of concomitant pseudohypoparathyroidism and bilateral ovarian teratoma. A 35-year-old Caucasian female visited the clinic with complaints of carpal spasms, hand paresthesia, irritability and fatigue. Hypocalcemia detected from childhood was commenced with calcium supplements. A previous diagnosis of subclinical hypothyroidism due to thyroid hypoplasia, with negative anti-thyroid antibodies was reported and maintained on levothyroxine. At the age of 26, right ovarian cyst excision was performed (a histomorphological study confirmed a teratoma). Eight years later, a dermoid cyst was detected in the left ovary measuring 30x27x18mm, with no growth during regular follow-ups. No other clinically significant medical conditions in past medical history. She has a family history of ovarian cancer and diabetes mellitus type 2. Physical examination was unremarkable, except for positive Chvostek and Trousseau signs, shortened 4th metacarpal and 4th metatarsal bones on both sides. Initial lab tests showed significantly low calcium level - 4.0mg/dl, increased PTH—241 pg/ml and Phosphorus- 5.2 mg/dl. DEXA scan and other laboratory results were within the reference range. A diagnosis of pseudohypoparathyroidism type 1a was made. Improvement of symptoms was achieved with combined calcitriol and calcium citrate supplementation.

Conclusion: This is a rare case of concomitant PHP and bilateral ovarian dermoid cysts. While there is no clinical evidence that these two disorders share any genetic or other pathophysiological properties, presence of both conditions in a single patient raises suspicion and remains an area of further investigations and research.