Indian Journal of Dental Research

: 2008  |  Volume : 19  |  Issue : 1  |  Page : 74--77

Histochemical and polarization microscopic study of two cases of vegetable/pulse granuloma

BS Manjunatha1, GS Kumar2, Vandana Raghunath3,  
1 Dept of Oral Pathology, SJM Dental College and Hospital, PB Road, Chitradurga, Karnataka, India
2 KSR Institute of Dental Sciences and Research, KSR Kalvi Nagar, Tiruchengode, Tamil Nadu - 637 209, India
3 Narayana Dental College, Nellore, Andhra Pradesh, India

Correspondence Address:
B S Manjunatha
Dept of Oral Pathology, SJM Dental College and Hospital, PB Road, Chitradurga, Karnataka


Vegetable granuloma (VG) or pulse granuloma (PG) results from the implantation of food particles of plant or vegetable origin. It is usually seen in the periapical or in the sulcus areas. These lesions have been described as a distinct entity and classified into central and peripheral lesions according to the location. Central lesions are asymptomatic, whereas peripheral lesions present as painless sub-mucosal swellings. Many authors have postulated that food particles in VG or PG get implanted and are rapidly digested, and sometimes partly get altered by host responses. The cellulose part of plant foods being indigestible persists in the form of hyaline material, whereas the starch matter gets digested. This cellulose moiety invokes chronic granulomatous response.

How to cite this article:
Manjunatha B S, Kumar G S, Raghunath V. Histochemical and polarization microscopic study of two cases of vegetable/pulse granuloma.Indian J Dent Res 2008;19:74-77

How to cite this URL:
Manjunatha B S, Kumar G S, Raghunath V. Histochemical and polarization microscopic study of two cases of vegetable/pulse granuloma. Indian J Dent Res [serial online] 2008 [cited 2022 Jun 30 ];19:74-77
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 Case Reports


A 65-year-old man habituated to smoking and tobacco chewing reported to our hospital with a painful swelling on the right cheek region and inability to open the mouth for 3 months. The patient gave no history of any allergic illness or any allergy to medications. He had not undergone any dental treatment in the past.

Intraoral examination revealed an ulcero-proliferative lesion of about 3 3 cm with a raised and indurated border in the right retro-molar region extending on to the adjacent gingival and buccal mucosa [Figure 1]. The submandibular lymph nodes were enlarged. The clinical features were suggestive of squamous cell carcinoma. No radiographic changes were observed in the underlying bone.

An incisional biopsy was taken from the anterior part of the lesion, and the histopathological diagnosis was that of a 'non-specific granuloma with foreign body reaction'. A second incisional biopsy from an adjacent site with more depth was advised to rule out the possibility of squamous cell carcinoma.

Microscopically, the second tissue showed a diffuse granuloma densely infiltrated with both acute and chronic inflammatory cells and eosinophils, along with intersecting areas of fibrosis. A pale, eosinophilic, hyalinised area resembling starch cells associated with a variety of inflammatory cells was observed in one of the sections [Figure 2]. The granuloma extended into the submucosa, to involve large islands of muscles, causing degeneration of muscle fibers [Figure 3]. Some muscle cells with prominent central nuclei and scattered multinucleated giant cells of foreign body type were also observed [Figure 4],[Figure 5]. An ulcerated oral epithelium was seen overlying the granuloma. A final diagnosis of vegetable granuloma associated with eosinophils was made based on the finding of homogenous, pale, eosinophilic, hyalinised vegetable matter along with infiltration of eosinophils deep into the muscles.


A 38-year-old female patient presented with a painful swelling on the right lower side of the face. The swelling was extending from the angle of mandible to the parasymphysis region antero-posteriorly and from ala-tragal line to 2 cm inferior to lower part of the angle of the mandible. On palpation, the swelling was bony hard and tender with radiating pain to the right ear. Past dental history revealed similar lesion, which had occurred in the same area about 11 years back and had been operated without any ensuing complications.

Intraoral examination revealed a large lesion in right posterior mandible with expansion of both buccal and lingual cortices with perforation in 48 regions. Mouth opening was restricted and teeth from 44 to 48 were missing. Radiographically, a multilocular radiolucent lesion extending from the right ramus of the mandible to the left molar area, causing root resorption from 43 to 35 was observed [Figure 6]. The lesion was provisionally diagnosed as Ameloblastoma, which was later confirmed by the histopathologic features of excised lesion.

Microscopically, the excised mass showed follicles of ameloblastoma, varying in size and shape with many undergoing cystic degeneration and squamous metaplasia. Interestingly, one of the sections showed a homogenous, pale, eosinophilic, ellipsoid area containing individual starch cells, many of which were degenerating, but the discrete double-layered refractile hyaline membranes encasing them were prominent with surrounding granulomatous reaction [Figure 7]. In another smaller area, a collection of oval or round homogenous brown-colored granules suggestive of vegetable matter appeared with few multinucleated giant cells surrounding it.

Histochemical staining

Various histochemical staining procedures such as PAS [Figure 8] with and without diastase, van Gieson [Figure 9], von Kossa, Gram's, Giemsa, AFB, Congo red and Perl's Prussian blue were done for both cases. The staining reactions and results are shown in [Table 1].

Polarization microscopic findings

When the vegetable matter was examined under polarized light, it appeared as birefringent refractile particles [Figure 10] and was similar to that in a previous report. [1] The encasing cellulose membranes appeared light and the starch contained in it appeared dark. The surrounding collagen showed very weak birefringence representing immature collagen fibers.

Other routine investigations, such as erythrocyte sedimentation rate (ESR), total RBC count, total and differential WBC count, platelet count, Hb% and specific investigations for bacterial and fungal infections, Wegener's granulomatosis, sarcoidosis, allergic granulomatosis, Crohn's disease, oral tuberculosis and Melkerson-Rosenthal syndrome, were done as in case-1 to rule out both local and systemic oro-facial granulomatosis.


Pulse granuloma (PG) is a controversial lesion with regard to its etiopathogenesis and nomenclature. It has been described in the literature under a variety of names, [1] since its inception in 1971. The recent term for this lesion is hyaline ring granuloma, which is reported to occur in inflammatory and developmental odontogenic cysts. [2]

Chou et al. have described these lesions as a distinct entity and classified them into central and peripheral according to the location. The etiopathogenesis for VG has been explained based on two concepts, i.e., exogenous and endogenous concepts. The concept of exogenous origin for these lesions is based on the suggestion of implantation of food particles of plant origin, through extraction sockets, deep periodontal pockets, unfilled root canals and grossly decayed teeth. [1] Animal experiments have lent evidence to this concept. [3] Talacko and Radden [3] have suggested that implanted food particles in VG or PG get rapidly digested and also get altered by host responses. The cellulose part of plant foods being indigestible persists in the form of hyaline material, whereas the starch matter gets digested. This cellulose moiety invokes chronic granulomatous response.

The endogenous origin is attributed to localized degenerative changes in the walls of blood vessels, [4] degraded collagen or fibrosed extravasated serum proteins [1] for these lesions. Some investigators [5] have considered the lesion to be caused by Torulopsis glabrata infection, a yeast-like fungus similar to the candida species, which was ruled out.

The diagnosis of PG is made only in the presence of starch granules, with cellulose envelopes that appear as hyaline rings. Variation in the number of hyaline structures accounts for the discrepancy between reported cases and reviewed cases of PG. [6]

The pale, eosinophilic, hyalinised areas identified in the H and E stained sections stained positive for PAS with and without diastase, thus confirming the cellulose content [Figure 8]. van Gieson was positive in the peripheral portion of the vegetable matter, and it represented the peripheral condensation of collagen [Figure 9] in both the cases. Both the hyalinised areas and the homogenous brown-colored granules were negative for von Kossa stain, implying that these were not calcified structures.

Thus, the hyalinised structures in our cases were positive for both PAS and van Gieson, which supports the hypothesis of McMillan et al . [4] Cellulose derived from the implanted plant food material accounts for PAS positivity, and the peripheral collagen condensation exhibits positivity to van Gieson.

In all the cases reported, the first case had a clinical presentation of an ulcero-proliferative growth in the retro-molar area, mimicking a carcinoma. The histopathological features consisted of a granulomatous reaction of foreign body type and showed a variety of inflammatory cells associated with occasional 'hyaline rings'. An interesting feature was the finding of eosinophils admixed with lymphocytes in the ulcerated areas and in the deeper regions between the muscles. Some muscle cells with prominent central nuclei resembling the ganglion cells [Figure 4] were also observed. This was confirmed by PTAH stain for muscle fibers (results in [Table 1]).

Wegener's granulomatosis was ruled out based on normal C reactive protein, ESR, and negative antineutrophil cytoplasmic antibody tests. As the lesion was not seen in the midline, midline lethal granuloma too was eliminated from the list. Considering Crohn's disease, many blood investigations such as ESR, total platelet and RBC counts, and hemoglobin levels were performed. The values of all these were within normal limits, and there was no complaint of persistent lip swelling or cobble stone appearance of oral mucosa.

The differential count of all types of WBC was also normal, ruling out the possibility of allergic oral granulomatosis. The patient also gave no history of facial paralysis, edema of his face, and lip swelling. This resulted in excluding Melkerson-Rosenthal syndrome.

Finally, sarcoidosis was thought of, and later calcium level in both serum and urine was investigated. The results were within normal limits.

In this case, since there was no history of trauma or surgery, the implantation of the pulses into the submucosa could have been through the ulcerated epithelium.

Thus, all investigative procedures and histopathologic examination, the site, and the appearance of the lesion pointed to the final diagnosis of VG.

The second case presented as a recurrent multilocular radiolucent lesion in the right posterior mandible, which was diagnosed as ameloblastoma. Histologically, the excised specimen showed many ameloblastoma follicles with few large, pale, eosinophilic, hyalinised area lined by double layered cellulose-like material and a collection of homogenous round to oval, brown granules surrounded by few multinucleated giant cells.

In contrast to the first case, the second case, which had a history of being operated for a similar lesion, was elicited, and perforated cortical plates near the 48 region were observed. These could have helped in the entry of vegetable matter.

Clinically, most of the PGs follow an indolent course, and many have been reported as chronic periostitis. [7] Histopathologically, these constitute a classical foreign body granuloma with or without hyaline structures. [1],[4],[6] The diagnosis remains largely on microscopic features and is rarely diagnosed clinically. [2] Hyaline rings, if present in few numbers, can go undetected if extensive sampling is not done.

PG has been reported in association with many odontogenic cysts [2],[8] and in chronic periostitis. [5]

The presence of inflammatory infiltrate with abundance of eosinophils, extending from the ulcerated areas and involving the muscles as observed in the first case, is consistent with the diagnosis of 'eosinophilic ulcer'. Eosinophilic ulcer is a self-limiting benign, ulcerative condition of oral mucosa without a definitive etiology. It is seen commonly on the tongue, buccal mucosa, and lip and was considered a distinct clinical entity by Shapiro and Juhlin. [9] The clinical suspicion of squamous cell carcinoma was, however, ruled out by microscopic examination of two biopsies and extensive sampling. Various factors such as psychological, physical, and socio-economical impact on patient in case-1 can be prevented or minimized if adequate measures are taken in establishing the diagnosis. In such cases, microscopic examination with adequate tissue sampling and serial sections may be helpful. Therefore, PG may be included in the differential diagnosis of ulcero-proliferative lesions.

In case-2, these PG or foreign body reaction may hinder postoperative healing and prognosis or final outcome.

Thus, our cases showed the presence of PG in association with eosinophils and with ameloblastoma, and this kind of association appears to be unnoticed and unreported previously.


The authors wish to thank Dr. Ravikala Rao, Professor of Pathology, SDM College of Medical Sciences and Hospital, Dharwad, India, for her valuable opinion in case-1. Authors also thank the Principal and the Management of SJM Dental College and Hospital, Chitradurga, for all the support given in publishing this article.


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