Thymus carcinoid in multiple endocrine neoplasia syndrome type 1 (MEN-1)

A discussion this week included thymus carcinoid in MEN-1.


References: Sadacharan D, et al. Rapid development of thymic neuroendocrine carcinoma despite transcervical thymectomy in a patient with multiple endocrine neoplasia type 1. Indian Journal of Endocrinology and Metabolism. 2013 Jul-Aug;17(4):743-746. doi:10.4103/2230-8210.113774.

Teh BT, et al. Thymic carcinoids in multiple endocrine neoplasia type 1. Annals of Surgery. 1998 Jul;228(1):99-105.

Summary: Thymic carcinoid is a rare malignancy, associated with MEN-1 and has no effective treatment (Teh et al, 1998). This is an insidious tumor not associated with Cushing’s or carcinoid syndrome. Local invasion, recurrence, and distant metastasis are common.

Teh et al (1998) recommended the following:

  • In asymptomatic gene carriers with biochemical evidence of hyperparathyroidism, parathyroidectomy with concurrent thymectomy should be considered as soon as possible.
  • In young gene carriers without evidence of hyperparathyroidsim, careful and regular follow-up should be done, including a CT scan or MRI of the chest as well as an octreoscan.

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A case report by Sadacharan et al (2013) estimate that thymic neuroendocrine (NE) tumors are reported in only 1-8% of cases and are a major cause of mortality in MEN-1 and gastroentero pancreatic tumors, and are detected approximately 7-29 years after surgical treatment of primary hyperparathyroidism (PHPT). They found a complete surgical excision through a trans-sternal route is the only curative treatmet for thymic NE tumors. Aggressive enbloc resection of involved structures is recommended. Some have advocated routine postop radiotherapy to prevent loco-regional recurrence (Teh et al, 2013).

They further claim that MEN-1 patients need to be screened for thymic NE tumors by routine annual CT or MRI of the thorax even after transcervical thymetcomy (TCT) at the time of parathyroid surgery.