Thymic carcinoid and parathyroid hyperplasia detection with 99mTc-MIBI men type 1

Area of Science:

• Endocrinology
• Nuclear Medicine
• Oncology

Background:

• Multiple Endocrine Neoplasia type I (MEN I) is a rare genetic disorder characterized by tumors in endocrine glands.
• Primary hyperparathyroidism is a common manifestation of MEN I, often requiring localization of hyperfunctioning parathyroid glands.
• Neuroendocrine tumors can occur in MEN I patients, sometimes presenting as unexpected mediastinal masses.

Observation:

• A 35-year-old male with a history of hypercalcemia, renal lithiasis, and diarrhea was diagnosed with familial MEN I.
• Technetium-99m-MIBI scintigraphy revealed a hyperfunctioning parathyroid gland and an anterior mediastinal mass.
• CT-guided biopsy of the mediastinal mass confirmed a thymic carcinoid, a type of neuroendocrine tumor.

Findings:

• 99mTc-MIBI scintigraphy effectively localized both primary hyperparathyroidism and an ectopic neuroendocrine tumor in a MEN I patient.
• The thymic carcinoid was successfully removed and histologically confirmed.
• This case demonstrates the utility of 99mTc-MIBI in identifying diverse endocrine pathologies within MEN I syndrome.

Implications:

• 99mTc-MIBI scintigraphy can be a valuable tool for comprehensive tumor localization in MEN I patients.
• Early detection and localization of associated tumors, including neuroendocrine neoplasms, can improve patient management.
• This imaging modality may aid in identifying unexpected tumors beyond the typical parathyroid and pituitary manifestations of MEN I.