What is pulse granuloma?

Pulse Granuloma: A Foreign Body Reaction to Vegetable Matter

Pulse granuloma is a rare benign entity characterized by a foreign body reaction to vegetable particles, featuring distinctive hyaline rings and multinucleated giant cells. 1, 2

Histopathological Features

• Pulse granulomas demonstrate characteristic microscopic findings including:

  • Hyaline rings and convoluted structures 1, 3
  • Multinucleated foreign body giant cells 3, 4
  • Acute and chronic inflammatory cells 1
  • Vegetable matter/debris within or near the hyaline rings 3
  • Calcified basophilic granules in some cases 2

• Three morphologic variants have been described:

  • Hyaline predominant (can mimic amyloid) 4
  • Cellular predominant (can mimic spindle cell neoplasms) 4
  • Sclerosing mesenteritis-like 4

Anatomical Distribution

• Most commonly reported in the oral cavity 1, 2, 5
• Can be found in various locations throughout the gastrointestinal tract:
  • Rectum 1
  • Small and large intestine 4
  • Meckel's diverticulum 2
  • Appendix 4
  • Gallbladder 3, 4
• Also reported in other sites:
  • Lungs 1, 4
  • Liver, mesentery, omentum, peritoneum 4
  • Reproductive organs (cervix, ovary) 4

Pathogenesis

• The etiology was historically controversial with competing theories:
  • Vascular degenerative changes 3
  • Reaction to vegetable material 3
• Current evidence strongly supports an exogenous pathogenesis from entrapped food particles introduced through mucosal trauma or injury 3, 4
• Ultrastructural studies and experimentally induced lesions in animals support the vegetable material theory 3
• Histologically processed legumes show similar structures to those identified in pulse granulomas, supporting the entrapped food origin 4

Clinical Significance

• Pulse granulomas may form mass lesions that can be clinically concerning for neoplasia 4
• More commonly, they are incidental findings on microscopic examination 3
• When detected incidentally, pulse granulomas can suggest underlying pathology such as:
  • Mural abscess 3
  • Fistula 3, 4
  • Perforation of the gut 3
• All reported patients with gastrointestinal pulse granulomas had a history of intestinal injury or disease, including:
  • Diverticulitis 4
  • Fistulas 4
  • Adenocarcinoma 4
  • Perforation 4
  • Inflammatory bowel disease 4
  • Appendicitis 4
  • Anastomotic site leak 4

Management

• Treatment consists of curettage or surgical excision 5
• Prognosis is excellent, with patients typically doing well on follow-up 4
• Recognition of this entity's distinctive histopathologic features can prevent unnecessary diagnostic procedures and expense 1, 2

Differential Diagnosis

• Amyloid (for hyaline predominant variant) 4
• Spindle cell neoplasms (for cellular predominant variant) 4
• Sclerosing mesenteritis 4
• Other granulomatous conditions 6