Cystic parathyroid glands in MEN1: A rare entity?

Multiple Endocrine Neoplasia Type 1 with Functional Parathyroid Cysts

A 51-year-old woman was admitted because of hypercalcemia. Neck ultrasonography and computed tomography revealed the presence of parathyroid cysts on both sides. After primary hyperparathyroidism was diagnosed by technetium-99m-methoxyisobutylisonitrile scintigraphy, the patient was successfully treated with total parathyroidectomy and autotransplantation. She also had a non-functioning pancreatic neuroendocrine tumor, prolactinoma, and adrenal tumors with subclinical Cushing's syndrome. Given these clinical features and her family history, multiple endocrine neoplasia type 1 (MEN1) was suspected, and germline DNA sequencing revealed a missense mutation (c.1013T>C, [corrected] p.Leu338Pro) in exon 7 of MEN1. This case demonstrates the phenotypic and genetic diversity of MEN1.

Multiple endocrine neoplasia type 1 combined with thyroid neoplasm: A case report and review of literatures

BACKGROUND

Multiple endocrine neoplasia type 1 (MEN1) is a rare hereditary tumor syndrome inherited in an autosomal dominant manner and presents mostly as parathyroid, endocrine pancreas (such as gastrinoma) and anterior pituitary tumors. At present, papillary thyroid carcinoma (PTC) and nodular goiter are not regarded as components of MEN1.

CASE SUMMARY

A 35-year-old woman presented with MEN1 accompanied by coinstantaneous PTC and nodular goiter. The pathological diagnosis was PTC with cervical lymph node metastasis, nodular goiter, parathyroid cyst and adenomatoid hyperplasia. Genetic testing was performed and a MEN1 gene mutation was detected. The patient underwent unilateral lobectomy of the thyroid gland and surgical removal of the parathyroid tumors. At 18 mo of follow-up, ultrasonic examination of the neck showed no abnormality. Serum calcium and parathyroid hormone levels were normal. No new MEN1-associated tumors were detected.

CONCLUSION

The role of inactivating mutations of MEN1 gene in tumorigenesis of PTC and/or nodular goiter remains to be determined by more case reports and further research.

Unusual presentations of functional parathyroid cysts: a case series and review of the literature

Background

Cysts of parathyroid origin are sometimes encountered and can easily be mistaken as thyroidal cysts. Functional parathyroid cysts, with symptoms and signs of hyperparathyroidism, are rare and may be a diagnostic challenge to clinicians. We report here on three cases of functional parathyroid cysts that illustrate diagnosis difficulties related to unusual clinical presentations in three Caucasian women, including negative parathyroid scintigraphy.

Case presentations

Patient 1, an 87-year-old Caucasian woman presented with confusion and dysphagia. She had hypercalcemia and elevated parathyroid hormone levels suggesting primary hyperparathyroidism. Parathyroid scintigraphy did not reveal any focal uptake, but a computed tomography scan of her neck identified a large cyst in the upper right thyroid region. At cervicotomy, a parathyroid cystic adenoma was removed. Patient 2, a 31-year-old Caucasian woman was investigated after a hypertensive crisis related to primary hyperparathyroidism. Cervical ultrasound identified a large cystic lesion in the lower left thyroid lobe that was removed by minimally invasive cervicotomy. Patient 3, a 34-year-old Caucasian woman presented with an indolent growing mass of the neck and a past medical history of kidney stones. Primary hyperparathyroidism was diagnosed. Ultrasound showed a cystic mass, but parathyroid scintigraphy was negative. Cervical exploration revealed a large cystic adenoma, containing high parathyroid hormone levels.

Conclusions

Diagnosis of functional parathyroid cysts can be challenging due to various clinical presentations and negative parathyroid scintigraphy. Surgery, but not fine-needle sclerotherapy, appears to be the safest treatment option. Despite its rarity, differential diagnosis of cystic lesion of the neck should include primary hyperparathyroidism due to functional parathyroid cysts.