Other tumors

Granular cell tumor

Last author update: 1 July 2015
Last staff update: 11 November 2022 (update in progress)

Copyright: 2003-2023,, Inc.

PubMed Search: Granular cell tumor [title] lung

Roseann I. Wu, M.D., M.P.H.
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Cite this page: Wu R. Granular cell tumor. website. Accessed April 2nd, 2023.
Definition / general
  • Sessile polypoid endobronchial neoplasm
  • May rarely form mass in the lung, mimicking carcinoma
  • Similar to granular cell tumors at other sites
  • Also known as Abrikossoff tumor
  • Granular cell myoblastoma, granular cell nerve sheath tumor, granular cell schwannoma
  • All ages, with peak in middle age (4th-6th decades)
  • Slight female predominance (3:2)
  • May be more common in black persons
  • Neoplastic, typically solitary, small (< 5 cm)
  • Typically benign, but rare reports of malignant cases
  • Coexistent malignancy may occur
  • Controversial histogenesis, but appears neural / schwannian
Clinical features
  • Incidental finding or may present as obstructive intrabronchial mass with intact overlying mucosa
Radiology description
  • Intrabronchial mass that may show infiltration
  • Peripheral lung parenchymal mass may show spiculated borders, mimicking malignancy
Prognostic factors
  • Incomplete resection could lead to recurrence
Case reports
  • Conservative therapy, with surgery as needed
Clinical images

Contributed by Roseann Wu, M.D., M.P.H.
Bronchoscopy Bronchoscopy


Gross description
  • White-tan, ill-defined mass with gritty cut surface
  • Necrosis and hemorrhage are uncommon
  • Typically small (< 5 cm)
Microscopic (histologic) description
  • Pushing or irregular, infiltrative border
  • Polygonal cells with abundant, eosinophilic, coarsely granular cytoplasm and small, hyperchromatic, oval to slightly irregular nuclei with indistinct nucleoli
  • May form targetoid cytoplasmic inclusions resembling Michaelis-Gutman bodies
  • No / rare mitoses, no necrosis, no vascular invasion
  • May show overlying pseudoepitheliomatous hyperplasia
Microscopic (histologic) images

Contributed by Roseann Wu, M.D., M.P.H.
Overlying pseudoepitheliomatous hyperplasia

Overlying pseudoepitheliomatous hyperplasia



H&E of tracheal granular cell tumor H&E of tracheal granular cell tumor

H&E of tracheal granular cell tumor

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Moderate atypia

Moderate atypia

Cytology description
  • Variably cohesive, moderate cellularity
  • Monotonous population of rounded epithelioid cells with abundant, granular, foamy cytoplasm best appreciated on Romanowky-stained preparations
  • Indistinct cytoplasmic borders
  • Small, bland nuclei with fine chromatin; nuclei may be eccentric, imparting plasmacytoid and oncocytic appearance
  • Naked nuclei may be seen due to smearing of delicate cytoplasm
Cytology images

Contributed by Roseann Wu, M.D., M.P.H.
ThinPrep, esophageal wall

ThinPrep, esophageal wall

Pap, esophageal wall

Pap, esophageal wall

Labial granular cell tumor, DiffQuik Labial granular cell tumor, DiffQuik

Labial granular cell tumor, DiffQuik

Positive stains
Electron microscopy description
  • Numerous secondary and tertiary cytoplasmic lysosomes
Molecular / cytogenetics description
Differential diagnosis
  • Acinic cell carcinoma
  • Carcinoid with oncocytic cells: positive for chromogranin and synaptophysin
  • Carcinomas and smooth muscle tumors with granular cells
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