Atypical carcinoid tumour of the thymus: a study of eight cases.
Atypical carcinoids of the thymus are rare neoplasms of uncertain prognosis. We have studied eight cases (six male, two female; age range 48-60 years, mean 55 years), none with evidence of a paraneoplastic neuroendocrine syndrome. Tumour size was large and ranged from 7.5 to 10 cm. Microscopically, all had a nesting/insular or trabecular pattern, eosinophilic cytoplasm, round nuclei with fine chromatin and small nucleoli. No small cell features were evident. Mitotic activity ranged from 2 to 21 per 1.52 mm2. Focal necrosis was seen in all cases. All were positive for cytokeratin (AE1/AE3, CAM 5.2) and the neuroendocrine markers NSE, synaptophysin and chromogranin; five cases were positive for calcitonin. On electronmicroscopy all contained dense core granules, often numerous. Three cases were stage I and five stage III (infiltrating lung or chest wall). Follow-up information was available in four cases (one stage I and three stage III): the stage I tumour had local recurrence and metastasis to the lung within a year whilst the three patients with stage III tumours died of liver, bone and brain metastases within 3 years.
Valli
M
M
Department of Histopathology, University of Ancona, Italy.
Fabris
G A
GA
Dewar
A
A
Chikte
S
S
Fisher
C
C
Corrin
B
B
Sheppard
M N
MN
D002276:Carcinoid Tumor / Q000737:chemistry / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D013953:Thymus Neoplasms / Q000737:chemistry / Q000473:pathology*