A typical thymic carcinoid tumour within a thymolipoma: report of a case and review of combined tumours of the thymus

Abstract

Correspondence to Christina Steger, Christina.M. Steger@i-med.ac.at CS and HS contributed equally to this work. SummaryThymolipomas are rare tumours located in the anterior mediastinum. Sometimes these tumours may be combined with thymomas or lymphomas. We present a unique case of a thymic carcinoid arising within a thymolipoma. A 68-year-old patient presented with chronic chest and neck pain, which was initially thought to be caused by coronary artery disease. A chest x-ray, exercise tolerance test and coronary angiography were unremarkable. The following CT scan of the neck and chest showed a small tumour in the anterior mediastinum. A robotic-assisted thymectomy was performed and histological examination revealed a neuroendocrine tumour of the thymus within a thymolipoma. The patient was discharged 3 days after surgery in good general condition. BACKGROUND

Superior mediastinal typical carcinoid detected by 99mTc-MIBI SPECT/CT imaging

“…The mechanism of the elevation of PTH and hypercalcemia may be as follows: As carcinoid tumors originate in the cells of APUD system, they can express different peptides and biogenic amines, [1] such as 5-hydroxytryptamine (5-HT),bradykinin, adrenocorticotropic hormone, thus causing carcinoid syndrome, ectopic adrenocorticotropic hormone (ACTH) syndrome. [3] In this case,no tumor was detected on the parathyroid gland. And when the mediastinal lesion was removed, there was a dramatic decline of iPTH.…”

“…[1,2] Typical and atypical carcinoid tumors are distinguished on the basis of morphology, mitosis count, and the presence or absence of necrosis. [3,4] Typical carcinoid has a less aggressive behavior; it rarely relapses after complete surgical resection, and nodal involvement and distant metastases are rare. [5,6] Carcinoids occur most frequently (90% of cases) in the gastrointestinal tract.…”

Thymolipoma With Sebaceous Differentiation

“…Included in this group were cases of thymoma or thymic carcinoma arising in a thymolipoma, 8,9 thymolipoma with a cystic lymphangioma, 10 and a case of typical carcinoid tumor in a thymolipoma. 11…”

Mesenchymal Tumors of the Mediastinum: An Update on Diagnostic Approach

“…31 Rarely, thymolipomas may contain thymomas or thymic carcinoid tumors. 32,33 Thymolipomas are well-circumscribed, soft, and yellow on the cut surface (Fig. 1A).…”

“…Whether thymolipoma is a benign neoplasm, hamartoma, or merely fatty hyperplasia in a hyperplastic thymus remains controversial, however, the identification of HMGA2 gene translocation in 1 case suggests that it may arise from neoplastic process 31. Rarely, thymolipomas may contain thymomas or thymic carcinoid tumors 32,33…”