Rectal pulse granuloma: a rare condition presenting as a subepithelial lesion

Abstract

Figures

Endoscopic images showing a distal rectal subepithelial lesion: a as a subepithelial protrusion with erosive changes of the overlying mucosa; b 1 week later, with no evidence of the erosive overlying mucosa.

Appearance of the lesion 10 weeks later on: a colonoscopy, showing an ill-defined submucosal bulge with a polyp on its surface; b on endoscopic ultrasonography, showing a 5.2 × 3.1-mm heterogeneous mass originating from the submucosal layer (arrowheads).

Histopathologic appearance of the resected lesion showing a granulomatous inflammatory process, with numerous foreign-body giant cells (circles), plant-like matter (arrows), and convoluted hyaline rings (stars), suggestive of a pulse granuloma (hematoxylin and eosin [H&E] staining, magnification × 200).

Full text

A pulse granuloma is a rare benign entity that typically occurs in the oral cavity 1 . Herein, we report a case of a subepithelial lesion (SEL) located in the distal rectum, which was diagnosed as a rectal pulse granuloma after its removal by endoscopic submucosal dissection (ESD).

A 66-year-old man with no significant medical history underwent colonoscopy for adenoma screening. Colonoscopy revealed multiple polyps, along with a subepithelial protrusion in the distal rectum, which was approximately 0.7 cm in size, with erosive changes of the overlying mucosa ( Fig. 1 a ). The patient underwent endoscopic polypectomy 1 week later, at which time the erosive mucosa was noted to have recovered completely ( Fig. 1 b ). After 10 weeks, the patient underwent further tests, with white-light endoscopy now showing an ill-defined submucosal bulge with a convex polyp on its surface ( Fig. 2 a ). Endoscopic ultrasound (EUS) revealed a 5.2 × 3.1-mm heterogeneous mass originating from the submucosal layer ( Fig. 2 b ). The lesion was removed by ESD ( Video 1 ). Histologic analysis revealed acute and chronic inflammatory cells, foreign-body giant cells, plant-like matter, and convoluted hyaline rings, supporting the diagnosis of a pulse granuloma with a foreign-body reaction ( Fig. 3 ), consistent with a pulse granuloma. The patient was discharged following ESD, without any complications.

Endoscopic images showing a distal rectal subepithelial lesion: a as a subepithelial protrusion with erosive changes of the overlying mucosa; b 1 week later, with no evidence of the erosive overlying mucosa.

Appearance of the lesion 10 weeks later on: a colonoscopy, showing an ill-defined submucosal bulge with a polyp on its surface; b on endoscopic ultrasonography, showing a 5.2 × 3.1-mm heterogeneous mass originating from the submucosal layer (arrowheads).

Histopathologic appearance of the resected lesion showing a granulomatous inflammatory process, with numerous foreign-body giant cells (circles), plant-like matter (arrows), and convoluted hyaline rings (stars), suggestive of a pulse granuloma (hematoxylin and eosin [H&E] staining, magnification × 200).

Endoscopic submucosal dissection of a subepithelial lesion initially seen as a subepithelial protrusion in the distal rectum on colonoscopy and confirmed to be originating from the submucosal layer on endoscopic ultrasound; histopathology of the resected specimen showed it to be a pulse granuloma.Video 1

Since it was first described in the lung in 1969 by Knoblich 2 , pulse granuloma has been reported in the oral and nasal cavity, skin, knee, fallopian tube and ovary, and intrahepatic portal vein 1 3 . It can also occur in the stomach, small intestine, colorectum, peritoneum, and mesentery 1 4 5 . A pulse granuloma is characterized by a chronic granulomatous reaction to a foreign body of vegetable origin 4 . In the present case, the mucosal damage seen above the lesion may have been the path by which the foreign bodies penetrated into the submucosal layer. As a rare lesion, familiarity with this entity’s distinctive histopathologic features may avoid a delayed diagnosis or misdiagnosis.

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