Tumefactive Crohn's Disease Presenting as Multiple Colonic Mass‐Like Lesions Mimicking Colon Carcinoma in a Middle‐Aged Man: A Case Report

ABSTRACT

This case report highlights the importance of considering tumefactive Crohn's disease in the differential diagnosis of inflammatory bowel disease presenting with a colonic mass. This condition can resemble colorectal carcinoma in endoscopic and radiologic assessments, making histopathological examination critical for accurate diagnosis, which impacts surveillance protocols and medical management.

1. Introduction

Crohn's disease is a chronic inflammatory bowel disease (IBD) which can affect any part of the gastrointestinal system, with the colon being one of the most frequently involved sites. Characteristic histopathological features include segmental transmural inflammation and bowel wall thickening, which may result in inflammatory masses, strictures, fistulae, or penetrating disease. Although uncommon, tumefactive Crohn's disease, characterized by a tumor‐like inflammatory mass, represents a clinically important presentation [1, 2]. Given the high prevalence of colorectal cancer, the third most common malignancy worldwide, tumefactive Crohn's disease may closely mimic colonic carcinoma on endoscopic and radiologic evaluations, making diagnosis particularly challenging, especially in middle‐aged patients presenting with a solitary colonic mass. Only a limited number of cases have been reported in the literature. Recognition of this presentation is important because an incorrect diagnosis of malignancy may lead to overtreatment or unnecessarily extensive surgical resection [3]. This entity represents a diagnostic overlap between IBD and colorectal malignancy, with important implications for surgical planning, postoperative surveillance, and medical management. We report a case of tumefactive Crohn's disease presenting as a colonic mass that closely mimicked colon carcinoma.

2. Case Presentation

2.1. Case History/Examination

A 52‐year‐old male patient with a history of hemorrhoidectomy performed 8 and 10 years earlier, and a diagnosis of ulcerative colitis, was referred to our colorectal surgery department for total colectomy due to multiple colonic mass‐like lesions. He had been diagnosed with ulcerative colitis 18 months ago, presenting with initial symptoms of abdominal pain, diarrhea, and lower gastrointestinal bleeding. The initial colonoscopy revealed pancolitis, characterized by diffuse mucosal friability, ulceration, spontaneous bleeding, and significant exudate throughout the colon. The patient was treated with oral mesalazine 1200 mg three times daily, and adalimumab (Cinnora) 40 mg/0.8 mL administered subcutaneously every 2 weeks. He had no family history of IBD or gastrointestinal malignancy. He was a smoker and reported no alcohol consumption.

2.2. Methods (Differential Diagnosis, Investigations, and Treatment)

During the 18‐month disease course, he experienced two disease flare‐ups requiring hospitalization. Following the flare‐ups, repeat colonoscopy revealed three large polypoid lesions located in the ascending colon near the hepatic flexure, transverse colon, and descending colon near the splenic flexure (Figure 1). Biopsies were obtained from all lesions. Histopathological examination demonstrated moderate‐to‐severe chronic active colitis compatible with the active phase of ulcerative colitis. Cytomegalovirus infection was excluded, and no dysplasia was identified in any specimen. Contrast‐enhanced abdominopelvic computed tomography (CT) revealed asymmetric, mass‐like thickening of the intestinal wall affecting the splenic flexure, distal portion of the transverse colon, and proximal portion of the descending colon. After contrast injection, these colon segments showed heterogeneous enhancement, less than blood vessels. The bowel wall thickness measured up to 20 mm, and the length of the involved colon segment measured 55 mm. Severe pericolic fat stranding, engorgement of mesenteric vessels, and multiple small regional lymph nodes with a maximum short‐axis diameter of 6.5 mm were present. The appearance of these lesions on CT scan mimicked colonic mass, likely colon cancer; however, the engorgement of the mesenteric vessels, creeping fat, and the absence of nodular extension into the surrounding fat may point toward an inflammatory etiology as a differential diagnosis. No abnormalities were detected in the remaining colon, small bowel, or intra‐abdominal solid organs (Figure 2). Despite negative biopsy results for dysplasia or malignancy, the radiologic appearance and multifocal mass‐like lesions raised significant concern for colorectal carcinoma. After multidisciplinary evaluation, total colectomy was recommended. The patient underwent laparotomy through a midline incision. Intraoperatively, three palpable masses were identified in the hepatic flexure, transverse colon, and splenic flexure. No abnormalities were observed in the stomach, small intestine, liver, or gallbladder. A total colectomy with ileorectal anastomosis was performed, and the specimen was submitted for pathological evaluation.

FIGURE 1.

The colonoscopy showed three large polypoid lesions in the ascending colon near the splenic flexure, in the transverse colon, and in the descending colon near the hepatic flexure.

FIGURE 2.

Abdominopelvic contrast‐enhanced computed tomography scan. (A) The axial images reveal asymmetric, marked bowel wall thickening (Red circle) with heterogeneous enhancement and inflammatory stranding in the surrounding fat. (B) Coronal reconstructed images revealed the length of this abnormality and the shouldering distal edge of the lesion, which could mimic colon cancer (Red arrow).

2.3. Conclusion and Results (Treatment and Follow‐Up)

Gross pathological examination revealed three mass‐like lesions (from distal to proximal): The largest lesion was located 34 cm from the distal margin, exhibited a circumferential vegetative surface, and measured 8 × 7.8 × 1 cm. The second lesion was located 10 cm from the first mass and measured 4 × 2.2 × 1 cm. The third one measured 3 × 1.5 × 1 cm and was located 14 cm from the ileocecal valve. No gross omental seeding was identified (Figure 3). Microscopic examination showed prominent mucosal injury characterized by architectural distortion of the glands with relatively decreased mucosecretion. Some glands were dilated, accompanied by marked edema of the chorion. Neutrophilic infiltration was present in several glands with associated epithelial wall destruction and small focal ulcerations. Lymphoid aggregation was observed in the submucosa, interspersed within the muscular layer, and in the serosa, without formation of a definite fistula. No dysplasia or neoplastic mucosal lesions were identified (Figure 4). There were 28 resected regional lymph nodes showing reactive changes, and all the surgical margins were not involved. The final pathological diagnosis was destructive colitis compatible with tumefactive Crohn's disease. This unusual presentation produced multifocal mass‐like lesions that closely mimicked colorectal carcinoma both radiologically and macroscopically. After an uneventful recovery, the patient was discharged on the 10th postoperative day. At the time of writing, there were no complications with outpatient follow‐ups 8 months following surgery.

FIGURE 3.

(A) Histopathologic macroscopic evaluation revealed an attached portion of the terminal ileum measuring 14 cm in length and 1.5 cm in diameter, and an attached appendix measuring 7 cm in length and 1 cm in diameter. The colon measured 92 cm in length with an average diameter ranging from 2 to 5 cm. On sectioning, three masses (the white arrows) were identified (from distal to proximal): The largest mass (B) was located 34 cm from the distal margin and showed a circumferential vegetative surface, measuring 8 cm in length, 7.8 cm in diameter, and 1 cm in thickness. The second mass (C) was located 10 cm from the first mass and measured 4 × 2.2 cm with a thickness of 1 cm. The third mass measured 3 × 1.5 cm, with a thickness of 1 cm, and was located 14 cm from the ileocecal valve (in this figure, the mass was excised, and the resection site was marked).

FIGURE 4.

Histopathologic microscopic evaluation showed chronic active colitis pattern, represented by crypt architectural distortion, cryptitis, and crypt abscesses (stain, hematoxylin and eosin; magnification, (A) ×40, (B) ×100).

3. Discussion

The present case illustrates a rare presentation of tumefactive Crohn's disease manifesting as multiple colonic mass‐like lesions in a patient previously diagnosed with ulcerative colitis. Despite benign results of colonoscopic biopsies, the radiologic and macroscopic findings suggested colonic neoplasm, and the definitive diagnosis was established only after colectomy and complete pathologic evaluation. Histopathologic examination of the resected specimen demonstrated destructive chronic colitis with transmural lymphoid aggregates and deep mural involvement without evidence of neoplasia, findings consistent with tumefactive Crohn's disease rather than colon carcinoma. The pathogenesis of tumefactive Crohn's disease can be explained by recurrent flare‐ups and remissions, with inflammation playing a major role. The expression of metalloproteins and adhesion molecules affects the inflammatory process by altering the innate defense of the intestinal mucosa. The underlying mechanisms of tumefactive Crohn's disease are thought to involve chronic transmural inflammation, mural fibrosis, lymphoid aggregation, and inflammatory phlegmon formation, which collectively produce a localized mass‐like lesion, consistent with the broader inflammatory and fibrotic processes described in Crohn's disease [1, 4].

Most evidence is limited to isolated case reports and small case series, highlighting the rarity of this presentation. Fekih et al. [5], reported a series of 16 patients with pseudotumoral colonic Crohn's disease, and Tamzaourte et al. [6], described 8 additional cases, representing some of the largest published experiences with this entity. However, most reports consist of single cases, emphasizing its infrequent occurrence in routine clinical practice. Similar to our patient, several published cases were initially suspected to have colorectal carcinoma because of tumor‐like findings on imaging and colonoscopy. Sabbah et al. [7], described a 44‐year‐old man presenting with abdominal pain, weight loss, and subocclusive symptoms, in whom CT scan demonstrated circumferential thickening of the ascending colon and cecum associated with mesocolic lymphadenopathy, findings highly suggestive of malignancy. Definitive diagnosis was established only after right hemicolectomy. Likewise, Nacer et al. [8], reported an 80‐year‐old patient in whom surgical exploration revealed a cecal tumor, and histopathological examination ultimately confirmed Crohn's disease in its pseudotumoral form. Similar diagnostic difficulties have also been reported by Maamouri et al. [9], Mnif et al. [10], and Nogogna et al. [11].

Endoscopic and radiologic findings frequently overlap with those of colorectal cancer. Reported colonoscopic appearances include stenotic lesions, circumferential masses, vegetative lesions, and polypoid tumors. Common findings on CT imaging are focal bowel wall thickening, mass effect, regional lymphadenopathy, and inflammatory infiltration of surrounding fat. These features often make it difficult to distinguish from cancer preoperatively, and recent reviews emphasize that no single endoscopic or radiologic feature reliably excludes malignancy in this setting [12, 13, 14, 15]. In the present case, colonoscopy revealed three large polypoid lesions, and CT demonstrated multifocal mass‐like thickening with regional lymphadenopathy, closely mimicking colorectal cancer despite the absence of dysplasia or malignancy on colonoscopic biopsies. Similar discrepancies between biopsy findings and clinical suspicion have been described in previous reports, frequently leading to surgical resection for definitive diagnosis [5, 9, 10, 11].

Compared with previously reported cases, our patient exhibited several distinctive features. Most published cases involved a single dominant lesion, commonly affecting the right colon or ileocecal region [5, 8, 11], whereas our patient presented with three separate mass‐like lesions involving the hepatic flexure, transverse colon, and splenic flexure. In addition, unlike many reported patients who presented with inaugural Crohn's disease, our patient carried a prior diagnosis of ulcerative colitis. The final diagnosis of tumefactive Crohn's disease was established only after colectomy, representing a diagnostic reclassification of IBD. The diagnosis of Crohn's disease and ulcerative colitis is rarely altered to a different type of IBD. Many instances of IBD reclassification have been postsurgical; they involve patients who have undergone colectomy and exhibit features of Crohn's disease in the resected specimen, or who subsequently develop findings compatible with Crohn's disease [16]. Shamah et al. [17], reported the reclassification rate of 25% among 128 patients who underwent colectomy for ulcerative colitis with an average follow‐up of 20 years. Another study by Everhov et al. [18], involving 44,302 patients with IBD found that 18% experienced a change in their initial diagnosis, with 39% of these cases reclassified from ulcerative colitis to Crohn's disease. This feature adds further complexity to the diagnostic pathway and distinguishes our case from most previously reported cases of pseudotumoral Crohn's disease. Furthermore, although histologic confirmation from endoscopic macrobiopsies has been reported in a small number of patients, many reported cases, including ours, ultimately required examination of the resected specimen to establish a definitive diagnosis [9, 10, 11].

Whenever technically feasible, adequate tissue sampling should be obtained before definitive surgical intervention. However, clinicians should recognize the limitations of endoscopic biopsies, as superficial samples may not accurately reflect the underlying transmural disease process. Radiologic findings should likewise be interpreted cautiously, especially when inflammatory and neoplastic features coexist [19, 20]. Accurate preoperative diagnosis has important implications for surgical planning and postoperative management. The extent of resection, reconstruction strategy, surveillance protocols, and long‐term medical therapy may differ substantially between IBD and colorectal cancer [21, 22]. In cases when malignancy cannot be confidently excluded, surgical resection may remain necessary for both diagnostic and therapeutic purposes, as occurred in the present patient [23].

Lastly, it should be noted that Crohn's disease is a lifelong condition that requires multidisciplinary, interprofessional care and has grown increasingly complex. Current therapeutic approaches have focused on controlling inflammation through pharmacological treatments and timely surgical interventions to reduce symptoms of bowel damage. Achieving optimal outcomes in Crohn's disease requires not only expertise in current medical and surgical therapies but also careful attention to broader aspects of management, such as timely diagnosis, prompt treatment initiation, and close monitoring of therapeutic response. Treatment strategies for Crohn's disease now extend beyond achieving clinical remission. They also focus on endoscopic healing and consider additional goals like histological and transmural targets, with the aim of further altering disease progression [4, 24, 25]. In addition to conventional medical and surgical therapies, emerging adjunctive approaches such as hyperbaric oxygen therapy have been investigated in IBD, which suggests potential clinical benefit, particularly in fistulizing Crohn's disease; however, current evidence remains limited [26, 27]. Future integration of advanced therapies with dietary interventions, biological agents, and small molecules, alongside advances in monitoring tools and predictive biomarkers, may further enhance outcomes for patients with Crohn's disease [4].

4. Conclusion

Tumefactive Crohn's disease is an uncommon condition with distinct clinico‐morphological and epidemiological features, presenting with mass‐like lesions that closely mimic colorectal carcinoma. The preoperative diagnosis is often challenging. The final diagnosis is usually based on the histopathological evaluation of the surgical specimen. Accurate differentiation from colorectal malignancy is crucial, as it affects surveillance protocols and medical management.

Author Contributions

Ali Mehri: writing – original draft, writing – review and editing. Marzieh Rahimi: writing – original draft, writing – review and editing. Seyed Abbas Tabatabaee Yazdi: conceptualization, resources. Fatemeh Masoudi Nasab: resources. Hourieh Soleimani: resources. Majid Ansari: conceptualization, supervision, resources. Abbas Abdollahi: conceptualization, supervision, resources.

Funding

The authors have nothing to report.

Ethics Statement

This case report was prepared after obtaining the patient's informed consent for publication. No additional diagnostic tests or therapeutic interventions were conducted specifically for this case report.

Consent

Written informed consent was obtained from the patient to publish this case report and any accompanying images. The written consent is available for review by the Editor‐in‐Chief of this journal.

Conflicts of Interest

The authors declare no conflicts of interest.

Data Availability Statement

The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.