Lung tumor
Other carcinoma
Large cell undifferentiated carcinoma

Author: Deepali Jain, M.D. (see Authors page)

Revised: 21 December 2016, last major update September 2012

Copyright: (c) 2003-2016,, Inc.

PubMed Search: large cell undifferentiated carcinoma lung
Cite this page: Large cell undifferentiated carcinoma. website. Accessed March 29th, 2017.
Definition / General
  • Malignant epithelial neoplasm composed of large, atypical cells; subtypes include basaloid carcinoma, large cell neuroendocrine carcinoma, large cell carcinoma with rhabdoid phenotype, lymphoepithelial carcinoma (PubCan)
  • Tumor with solid nests of large polygonal and anaplastic cells without obvious squamous or glandular differentiation; may be undifferentiated squamous cell carcinoma or adenocarcinoma
  • Diagnosis of exclusion - cannot diagnose on small biopsies or in lymph node metastases
  • Extended panel of immunohistochemical markers can reclassify 60%; miRNA-based analysis can reclassify the balance, but clinical relevance is unknown (Am J Clin Pathol 2011;136:773)
  • 80% men
  • Often associated with peripheral eosinophilia and leukocytosis, due to tumor production of colony stimulating factor
  • Behavior is similar to adenocarcinoma
Case Reports
Gross Description
  • Usually peripheral lung; spherical tumor with well-defined borders and bulging, fleshy, homogenous gray-white cut surface
  • No anthracosis
  • Frequently involves thoracic wall
Micro Description
  • Large polygonal cells and anaplastic cells growing in solid nests without obvious squamous or glandular differentiation
  • Moderately abundant cytoplasm, well defined cell borders, vesicular nuclei, prominent nucleoli
Micro Images

Images hosted on other servers:

Rhabdoid cells

Various images

Tumors reclassified and unable to be reclassified with extended IHC panel

Virtual Slides

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Anaplastic tumor cells

Positive Stains
  • CK5 (56%), calretinin (38%), thrombomodulin (25%), mesothelin (13%), TTF1 (variable)
Electron Microscopy Description
  • Glandular (intracellular and extracellular lumina) and squamous (desmosomes, tonofilaments) features often present although not obvious with H&E staining