Lung tumor
Other carcinoma
Large cell undifferentiated carcinoma

Author: Roseann Wu, M.D. (see Authors page)

Revised: 29 January 2018, last major update December 2017

Copyright: (c) 2003-2018, PathologyOutlines.com, Inc.

PubMed Search: Large cell undifferentiated carcinoma of the lung[TI]
Cite this page: Wu, R. Large cell undifferentiated carcinoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/lungtumorlargecell.html. Accessed February 25th, 2018.
Definition / general
Essential features
  • Malignant, poorly differentiated epithelial neoplasm of lung composed of large atypical cells
  • Tumors lack morphologic and immunohistochemical evidence of glandular, squamous or neuroendocrine differentiation
  • Diagnosis of exclusion, which may overlap or be synonymous with pleomorphic carcinoma
Terminology
  • Large cell undifferentiated carcinoma and large cell carcinoma are synonymous
  • Previously, large cell carcinoma included variants such as basaloid carcinoma, large cell neuroendocrine carcinoma, lymphoepithelioma-like carcinoma, clear cell carcinoma, large cell carcinoma with rhabdoid phenotype
  • As of 2015 WHO classification, large cell carcinoma is a diagnosis of exclusion, with reclassification of the former large cell carcinoma subtypes into different categories (J Thorac Oncol 2015;10:1243)
  • May overlap or be synonymous with pleomorphic carcinoma; diagnostic terminology still evolving
ICD-10 coding
  • Use code specific for location of tumor
  • C34.90 Malignant neoplasm of unspecified part of unspecified bronchus or lung
Epidemiology
  • 80% men, adults aged 50 - 70
  • Associated with smoking
Sites
  • 50% with connection to large airway
  • Periphery of lungs
Pathophysiology
  • Behavior similar to other poorly differentiated lung carcinoma
Clinical features
  • Similar to other poorly differentiated non small cell carcinoma, i.e. cough, chest pain, shortness of breath
  • Typically larger than 5 cm
Diagnosis
  • Diagnosis of exclusion, therefore cannot definitively diagnose on small biopsies or in lymph node metastases
  • NSCC NOS (non small cell carcinoma, not otherwise specified) can be used on small biopsy / cytology specimens
  • Diagnosis of entity began to decline when TTF1 immunohistochemical staining was introduced
Radiology images

Images hosted on other servers:

2.7 cm lobulated mass

Prognostic factors
  • Generally poor prognosis
Case reports
Treatment
  • Dependent on stage: surgical excision, chemotherapy / radiation
Gross description
  • Usually peripheral lung and unifocal; spherical tumor with well defined borders and bulging, lobulated, homogeneous gray white "fish flesh" cut surface
  • Internal necrosis and hemorrhage common
  • No anthracosis
  • Frequently involves thoracic wall
Gross images

Images hosted on PathOut server:

Images contributed by Dr. Debra Zynger:

Right lung mass

Microscopic (histologic) description
  • Large, polygonal and anaplastic cells growing in sheets or solid nests
  • No clear adenocarcinoma, squamous or neuroendocrine morphology
  • Moderately abundant cytoplasm, well defined cell borders, vesicular nuclei, prominent nucleoli
  • Foci of central necrosis and hemorrhage may be present
Microscopic (histologic) images

Images hosted on PathOut server:

Images contributed by Dr. Roseann Wu:

Large cell carcinoma



Images hosted on other servers:

Rhabdoid cells

Various images

Tumors reclassified and unable to be reclassified with extended IHC panel

Virtual slides

Images hosted on other servers:

Various images

Cytology description
  • Large pleomorphic cells with a moderate to abundant amount of cytoplasm, vesicular nuclei, prominent nucleoli
Positive stains
Differential diagnosis
Board review question #1
Large cell carcinoma of lung will generally stain for which of the following immunohistochemical markers?

  1. CAM5.2
  2. Chromogranin
  3. p40
  4. SOX10
  5. TTF1
Board review answer #1
A. CAM5.2