Gastrointestinal tract-derived pulse granulomata: clues to an underrecognized pseudotumor

New Kids on the Block

CONTEXT.—

With the increasing development and use of iatrogenic agents, pathologists are encountering more novel foreign materials in retrieved gastrointestinal specimens. These colorful and unusual-appearing foreign materials can pose a diagnostic dilemma to those unaware of their morphology, especially if the relevant clinical history is lacking.

OBJECTIVE.—

To discuss the histopathologic features, clinical scenarios and significance, and differential diagnosis of relatively recently described, yet quickly expanding, family of iatrogenic agents that can present as foreign materials in gastrointestinal specimens-pharmaceutical fillers (crospovidone and microcrystalline cellulose), submucosal lifting agents (Eleview and ORISE), lanthanum carbonate, hydrophilic polymers, OsmoPrep, yttrium 90 microspheres (SIR-Sphere and TheraSphere), and resins (sodium polystyrene sulfonate, sevelamer, and bile acid sequestrants).

DATA SOURCES.—

We collate the findings of published literature, including recently published research papers, and authors' personal experiences from clinical sign-out and consult cases.

CONCLUSIONS.—

Correct identification of these iatrogenic agents is important because the presence of some novel agents can explain the histopathologic findings seen in the background specimen, and specific novel agents can serve as diagnostic clues to prompt the pathologist to consider other important and related diagnoses. Awareness of even biologically inert agents is important for accurate diagnosis and to avoid unnecessary and expensive diagnostic studies.

Pulse/hyaline ring granuloma revisited: etiologic role of seed-derived storage cells

The objectives are to precisely identify the cells that incite the formation of lesions that are generally known as "pulse granuloma" or "hyaline ring granuloma" that occur mostly in the oral cavity, in the lungs, in and around the gastrointestinal tract, and other sites, and to suggest an alternative name for these lesions that accurately reflects their etiology. Critical review of the medical and dental literature was undertaken, and the microscopic appearances of granuloma-inciting cells depicted in the literature and seen in our practices were compared with seeds and their contents originating from a variety of leguminous and non-leguminous plants. Sections of selected seeds were examined microscopically before and after digestion with saliva and alpha amylase and subsequent routine processing and staining with H&E, PAS, and iodine. Pre- and post-digestion slides were examined with polarized light. The morphology of the granuloma-inciting cells is identical to the storage cells present in seeds from a variety of leguminous and non-leguminous plants. The cells that trigger the formation of "pulse granulomas"/"hyaline ring granulomas" are storage cells that are derived from ingested seeds of leguminous and non-leguminous plants. The terms "pulse," "legume," and "lentil," which have been applied to these cells, are misnomers. Our findings indicate that the terms "pulse granuloma" and "hyaline ring granuloma" are not appropriate descriptors of these lesions. We recommend that they be replaced by "seed storage cell granuloma," a term that now accurately reflects the etiology of these lesions.

A 77-Year-Old Man with a Pulse Granuloma of the Descending Colon Identified by Fluorodeoxyglucose-Positron Emission Tomography (FDG-PET) Imaging 19 Months Following Surgical Resection for Rectal Carcinoma

Patient: Male, 77-year-old

Final Diagnosis: Pulse granuloma

Symptoms: None

Medication:—

Clinical Procedure: —

Specialty: Gastroenterology and Hepatology • Oncology

Abdominal elastotic lesions. A clinicopathologic study of 23 cases

Abdominal elastotic deposits are uncommon lesions that often presents as polyps. They show three histological patterns: fibroelastosis, angioelastosis, and elastofibroma. We describe 23 cases including rare locations, such as mesentery, greater omentum, hernia sac, spleen, peripancreatic fat, and hypodermal fat. The age of the patients ranged from 49 to 93 years (mean, 76.8 years). Most lesions were discovered incidentally in the microscopic study. The most frequent locations were peritoneal subserosa (43.5%) and mesentery/mesocolon/greater omentum (39.1%). The most common pattern was fibroelastosis (69.6%) followed by angioelastosis (26.1%). We observed one case of omental elastofibroma. A review of the 14 abdominal elastofibromas described including our case revealed that the age of the patients ranged from 45 to 88 years (mean, 68.5 years). Female predominance is striking (M:F, 1:12). The most common site was the stomach (50%). The greater omentum (14.3%), small intestine (7.1%), and pancreas (7.1%) are very rare sites for this lesion. Only one case before ours has been published in the greater omentum. The size of the lesions ranged from 0.7 cm to 8 cm (mean 3.2 cm). In 36.4% of the cases located in the digestive tract, the mucosa did not show alterations. Ulcerations (36.4%) or polypoid excrescences (18.2%) were mostly observed. Six (42.9%) cases were asymptomatic and six (42.9%) cases simulated a neoplasm. Two cases were associated with elastofibromas in other locations. Differential diagnosis includes amyloidoma, elastofibrolipoma, mesenteric elastic vascular sclerosis in neuroendocrine tumors, diverticular disease elastosis, pseudoxanthoma elasticum, pulse granuloma, and digestive lesions in patients treated with D-Penicillamine.

Characterization of Novel Injectable Lifting Agents Used in Colonic Polyp Removal: An Emerging Amyloid Mimic

Colon polypectomy can require an injection of a submucosal lifting agent to fully visualize and completely remove the polyp. To the best of our knowledge, this is the largest morphologic series on the novel lifting agents Eleview and Orise. The study consisted of 1 polypectomy and 8 colon resections from 9 patients: 6 women, 3 men (mean age=64 y); Orise=6, Eleview=3; the median time interval between injection and resection=16 weeks. Pathologic diagnoses of the polyps included tubular adenoma (n=4), tubulovillous adenoma (n=4), and sessile serrated adenoma/polyp (n=1). We report that a histologically processed Orise aliquot from the manufacturer showed similar histology to that seen in the specimens from patients with confirmed Orise injection. The morphology of the agents in the patient specimens changed with time status postinjection: immediate resection of the lifting agent showed basophilic, amorphous, and bubbly-extracellular material with prominent hemorrhage, and resection ∼3 months after lifting agent injection showed prominent hyalinized, pink-amorphous ribbons and globules with a foreign body giant cell reaction and fibrosis. The epicenter of the lifting agents was in the submucosa, and the agents were neither refractile nor polarizable. Because of the morphologic overlap with amyloid, 5 cases were stained with Congo Red, and all cases were negative. In conclusion, awareness of the morphology of these new lifting agents is important for accurate diagnosis and to avoid the diagnostic pitfall of amyloid. These lesions can be definitively distinguished from amyloid by their nonreactivity on a Congo Red and familiarity with their characteristic clinicopathologic presentation.

Features of endoscopic procedure site reaction associated with a recently approved submucosal lifting agent

Endoscopic resection techniques, such as endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD), are frequently aided by injection of submucosal lifting solutions that create a plane for dissection and protect deeper mural layers. ORISE™ gel is a recently approved synthetic lifting solution that produces a localized inflammatory reaction associated with retained gel at the injection site. We describe a series of six cases of ORISE™-associated inflammatory lesions in patients who underwent endoscopic resections. Deposits comprised pale fibrillary or hyalinized eosinophilic material, depending on their age. All cases were associated with an inflammatory reaction composed of foreign-body giant cells and scattered eosinophils. ORISE™ gel extended laterally and deeply beyond residual tumors in all cases. Histochemically, the material proved to be negative for Congo Red, and mucicarmine, faint blue with Alcian blue, but positive for PAS and PAS-D. It stained blue with trichrome. Such deposits were absent in cases, wherein other widely-available lifting solutions were used. We compared ORISE™ deposits to histologically similar extracellular deposits, namely amyloid and pulse granulomata. Unlike ORISE™ material, amyloid deposits appear as waxy, more densely eosinophilic material, and stain positive with Congo Red. Amyloid demonstrated prominent intramucosal and perivascular distributions, features not seen in this series of ORISE™ deposits. Hyalinized pulse granulomata showed strong overlap with ORISE™ deposits, since they also comprise eosinophilic material associated with giant cell reaction. On the other hand, they form ribbons of glassy material in circumscribed lobules, unlike the ill-defined ORISE™ deposits. In summary, we describe the pathologic findings at injection sites in patients who underwent endoscopic procedures aided by the recently approved lifting agent, ORISE™. Pathologists should be aware of its appearance and associated reaction to avoid confusion with other common extracellular deposits seen in the gastrointestinal tract.

Disease, drugs, or dinner? Food histology can mimic drugs and parasites in the gastrointestinal tract

Microscopic foreign objects are sometimes found in gastrointestinal (GI) tract specimens. Some signify important diagnostic findings, such as parasitic or bacterial organisms and some medication resins. Partially digested fruits and vegetables can also be present, and some have been described in the literature as potential mimickers of clinically important findings. While animal protein appears as skeletal muscle on histologic examination, fruits and vegetables can show a wide variation under the microscope. To our knowledge, a thorough histologic examination of commonly eaten fruits and vegetables has not been published in the pathology literature. Herein, we present key morphologic features of fruits and vegetables that might be found in GI specimens, emphasizing potential mimics of significant pathologic findings.

Pulse Granulomas in Interval Appendectomy Specimens: Histochemical Identification of Cellulose Matter

Pulse granuloma is a rare pathologic condition considered to be a benign inflammatory reaction to foreign materials originated from ingested legume matter. As for pulse granulomas of the gastrointestinal tract, association with diverticular diseases is relatively common, but only a few pulse granuloma cases associated with appendicitis have been reported. This report presents histopathologic findings of pulse granuloma lesions observed in two appendectomy cases, with some histochemical examinations of cellulose matter which is reportedly a major component to provoke pulse granuloma reaction. Our patients in both cases were girls in their teens, and they underwent interval appendectomy for acute appendicitis. Both appendectomy specimens revealed ruptured walls with inflammatory granulation tissue with marked foreign body reaction including characteristic collections of ring-like, curled ribbon-like, and/or lobulated nephrosclerosis-like hyaline structures and various foreign bodies, in which microorganisms or amyloid deposition were not identified. The presence of cellulose matter was suggested by Sirius red stain, the IKI (iodine potassium iodide)-H₂SO₄ method, and birefringence by polarized light. Appendectomy materials due to acute appendicitis would include pulse granuloma reaction provoked by ingested materials with cellulose. Pathologists should be familiar with the concept and histopathologic features of pulse granulomas to avoid misinterpreting them as vascular lesions and/or amyloid deposition, or any infectious organisms.

Peritoneal Pulse Granulomas With Spiral Bodies Mimicking Peritoneal Carcinomatosis: A Case Report

Pulse (hyaline ring) granuloma, a rare entity first described in lung and oral cavity, has been reported under various names before the identification of hyaline rings as fragments of pulses (the edible seeds of legumes). Similar lesions were thereafter described in extra-oral localizations, mainly the gastrointestinal tract, or localizations having potential communication with the gastrointestinal tract. Recently, 2 reports described "spiral bodies" surrounded by foreign body-type multinucleated giant cell reaction in pulse granulomas, corresponding to remnant plant vascular structures (helical xylem elements). In this article, we report a case of a 70-year-old male patient presenting to our hospital for an incisional hernia repair. He had a history of antrectomy 2 years previously for perforated duodenal ulcer complicated with fecal peritonitis. During the hernia repair procedure, multiple peritoneal whitish nodules and one subserosal appendiceal nodule were found. Appendectomy and biopsy of a peritoneal nodule were performed. Microscopic examination showed nodular lesions located in the subserosa to be pulse granulomas. Also surrounded by histiocytes, spiraled thin and rigid foreign bodies were identified. In this article, we report a case of pulse granuloma with spiral bodies complicating perforated duodenal ulcer and mimicking a peritoneal carcinomatosis. We also provide a discussion on the origin of spiral bodies in light of relevant literature.

Elastotic Lesions of Intestinal Subserosal Fat: Report of Two Cases

We report 2 unusual elastotic lesions of intestinal subserosal fat. The first arose in the small bowel subserosa of a 64-year-old woman with volvulus. It was undetected macroscopically and consisted of a relatively circumscribed focus of elastosis, with essentially no evidence of fibrosis or blood vessel walls within. The second arose in the subserosa of the sigmoid colon in a 46-year-old woman with recurrent diverticulitis. It was also undetected macroscopically and consisted of a well-circumscribed nodule of elastic fibers surrounding prominent veins and arteries. Both patients had unremarkable postoperative courses. These lesions likely represent localized response to injury and are probably underrecognized.

Granulomas in the gastrointestinal tract: deciphering the Pandora's box

Granulomas are organised collection of activated histiocytes induced by a persistent antigen stimulus. A wide variety of antigens encountered by the gastrointestinal tract are of this nature and hence the resulting granulomatous inflammation represents a tissue reaction pattern. The potential causes can be broadly classified as infections or non-infectious immune reactions. There is also a group where a cause is never identified. Granulomas may be of varying morphological appearance, most commonly epithelioid, foreign body type, suppurative and necrotizing. This may provide a clue as to the aetiology; however, in most cases, the cause requires further inquiry. Pathologists may need to cut deeper levels to look for foreign material and apply special stains to look for microorganisms. Pathologists also need to be certain that the process is a true granuloma and not a mimic. The site of occurrence in the gastrointestinal tract and the clinical setting is often paramount in establishing the aetiology. For instance, infections are more likely the cause in developing countries or when there is immunosuppression. Similarly, granulomas in the stomach are usually due to Crohn's disease; however, it is only rarely the cause of granulomas isolated to the appendix.

A Peculiar Form of Breast Fat Necrosis Simulating Hyaline Ring Granuloma (So-called Pulse Granuloma): A Rare Complication of Hyperparathyroidism

Pulse granuloma is a rare, foreign body inflammatory reaction that occurs mainly in the oral cavity. It is exceedingly rare elsewhere, with only isolated cases described in the literature. We report the case of a 79-year-old woman with a history of normocalcemic hyperparathyroidism who presented to our hospital with a painful 4-cm lump in the upper quadrants-upper outer quadrant of her left breast. The clinical and radiological (BIRADS-5) findings were indicative of a malignant lesion. However, core needle biopsy revealed features simulating hyaline ring granuloma (pulse granuloma-like). A definitive diagnosis of lipomembranous fat necrosis was made by identifying its characteristic histomorphology. Histopathological study is essential to establish an exact diagnosis since clinical and imaging features may mimic breast carcinoma. To our knowledge, this is the first reported case of a hyaline ring granuloma-like in the breast, which may represent a peculiar form of degenerative change of lipomembranous fat necrosis.

Pulse Granulomas of the Gastrointestinal Tract and Gallbladder: Report of Five Cases

Hyaline rings with admixed multinucleated giant cells characterize pulse granulomas; the term pulse refers to edible seeds of legume vegetables. The etiology has been controversial, with theories including vascular degenerative changes or a reaction to vegetable material; ultrastructural studies and experimentally induced lesions in animals favor the latter. This lesion is typically seen in the oral cavity, with only rare reports in the gastrointestinal tract and gallbladder. We herein describe five cases of pulse granulomas identified in these sites. All cases contained foreign-body giant cells and vegetable debris within or near hyaline rings. Pulse granulomas may form mass lesions but are usually an incidental finding on microscopic examination. In incidentally detected cases, recognition of pulse granulomas can suggest a mural abscess, fistula, or perforation of the gut, findings which may not be grossly apparent. The presence of vegetable material in all five cases further supports an exogenous pathogenesis.

Disseminated hyaline ring granuloma in the omentum of a dog

Background

Hyaline ring granuloma (HRG) is an uncommon histopathologic finding of unsolved etiopathogenesis. According to the exogenous theory, HRG develops due to implantation of foreign material, most probably indigestible plant fragments. HRG is a comparatively rare condition in humans, mostly involving the oral cavity with very rare extraoral locations.

Case presentation

An 1-year-old mixed-breed dog in good condition was presented for routine ovariohysterectomy. Disseminated HGR were accidentally found in the omental adipose tissue during surgery. Histopathology revealed the presence of ring-like hyaline structures surrounded by granulomatous inflammation including foreign body-type multinucleated giant cells. The histochemical examinations indicated the exogenous plant origin of the foreign material.

Conclusions

The lesions were similar to the findings in humans with HRG. The definitive diagnosis remains largely based on histopathological examination supported by special histochemical stains. To the best of our knowledge, this is the first case of hyaline ring granuloma reported in a non-human species. Moreover, the omentum is an uncommon location for this condition.