Colon non tumor
Nonneoplastic, non-congenital lesions
Pulse granuloma

Author: Raul S. Gonzalez, M.D. (see Authors page)

Revised: 31 October 2018, last major update May 2016

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

PubMed Search: Pulse granuloma [title]
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Cite this page: Pulse granuloma. website. Accessed December 18th, 2018.
Definition / general
  • Granulomatous reaction to legume material that breaches the colonic mucosa
Essential features
  • Reactive process arising from foreign body (food material)
  • Usually clinically silent and incidental, but may form a mass lesion
  • Various microscopic appearances, but hyaline rings of pulse material must be present
  • "Pulse" is the seed material of legumes (beans, peas, peanuts, etc.)
  • It has also been described as "hyaline rings"
  • Can occur anywhere in gastrointestinal tract, but may occur most commonly in colon
  • More commonly recognized in oral cavity, mandible/maxilla and lung
  • If colon perforates, pulse can access the abdominal cavity and deposit anywhere within (e.g., ovary)
  • Granulomatous reaction to foreign material
  • Most often seen in colon damaged by perforation, diverticulitis, inflammatory bowel disease or malignancy
Clinical features
  • Generally an incidental finding but can may manifest as a mass lesion clinically
  • Associated with use of tobacco and NSAIDs (Am J Surg Pathol 2015;39:84)
Case reports
Microscopic (histologic) description
  • Hyaline predominant
    • More than half of lesion consists of pink hyaline rings/ribbons; other food present; inflammation and fibrosis minimal
  • Cellular predominant
    • Acute and chronic inflammation and fibrosis
    • Relatively less pulse and food material
  • Sclerosing mesenteritis-like
    • Rarest variant
    • Arises in mesentery and resembles sclerosing mesenteritis (inflammation, fibrosis), but pulse focally visible
    • Average size is 1.0 cm
Microscopic (histologic) images

Images hosted on Pathout server, contributed by Raul S. Gonzalez, M.D.:

Serosal hyaline predominant
pulse granulomas

Pulse material with numerous
foreign body giant cells

Cellular predominant pulse granuloma
with prominent inflammatory reaction

Scant pulse material embedded in colon
wall, alongside other fecal material

Negative stains
Differential diagnosis
  • Amyloidosis: positive with Congo red stain; inflammation generally not present
  • Sclerosing mesenteritis: for lesions in the mesentery; hyaline rings not present