Lung tumor
Carcinoid and related tumors
Carcinoid tumor

Topic Completed: 1 September 2012

Revised: 13 June 2019

Copyright: (c) 2003-2019,, Inc.

PubMed Search: carcinoid tumor[title] lung

Related Topics: central, peripheral

Deepali Jain, M.D.
Page views in 2018: 10,794
Page views in 2019 to date: 6,234
Cite this page: Jain D. Carcinoid tumor. website. Accessed July 20th, 2019.
Definition / general
  • World Health Organization classification recognizes 4 histologic subtypes of pulmonary neuroendocrine carcinomas (NECs), which include typical carcinoids (TCs), atypical carcinoids (ACs), small cell carcinomas (SCCs) and large cell NECs (LCNECs)
  • Also called well-differentiated neuroendocrine carcinoma
  • < 5% of primary lung tumors
  • Locally invasive, rarely metastasizes
  • Usually age < 40 years old
  • No gender predilection, not related to smoking
  • Occasionally occurs as part of MEN syndrome
  • May infiltrate or spread to local lymph nodes, but doesn’t affect prognosis
  • Rarely produces carcinoid syndrome (flushing, diarrhea, cyanosis)
  • 10 year survival is 50%
  • In children, involves lung or liver, may metastasize regardless of histology (Arch Pathol Lab Med 2003;127:1200)
Gross description
  • Either central (polypoid and endobronchial in major bronchi) or peripheral (solid / nodular)
  • Usually well defined, smooth, ivory to pink cut surface, no necrosis
Microscopic (histologic) description
  • Nests or trabeculae of medium sized polygonal cells with lightly eosinophilic cytoplasm, low nuclear grade, round to oval finely granular nuclei; may have rosettes or small acinar structures with variable mucin
  • Scanty vascular stroma, occasionally amyloid stroma with bone
  • No / minimal mitotic activity (< 2/10HPF), no necrosis
Microscopic (histologic) images

Images hosted on other servers:

Left: fig B; right: fig A

Positive stains
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