European Journal of Cardiovascular Medicine

Colorectal lesions represent a heterogeneous group of disorders that include infective and inflammatory colitis, non-neoplastic polyps, premalignant adenomas, and invasive carcinoma. Colorectal cancer remains a major cause of morbidity and mortality, and recent global estimates continue to place it among the most frequently diagnosed cancers and leading contributors to cancer-related deaths [1]. In parallel, chronic inflammatory disorders of the colon contribute significantly to impaired quality of life and healthcare utilization, particularly when symptoms such as rectal bleeding, diarrhea, and abdominal pain persist or recur. Understanding the histopathological pattern of colorectal disease in colonoscopy practice is important because it reflects both disease epidemiology and the diagnostic spectrum encountered in tertiary care pathology services.

Colonoscopy provides direct mucosal visualization and enables tissue sampling from suspicious areas, thereby bridging clinical assessment and definitive diagnosis. Nevertheless, visual impressions alone are insufficient to differentiate several entities, particularly in early malignancy, subtle dysplasia, and chronic colitis, where macroscopic changes can be minimal or nonspecific [9,11]. Histopathology remains the gold standard for lesion confirmation and classification, and it provides essential information on activity, chronicity, dysplasia, and invasive growth. The long-recognized adenoma–carcinoma sequence, supported by stepwise genetic alterations, forms the biological basis for surveillance strategies and endoscopic removal of premalignant lesions [7,8]. Large population data also show that effective detection and removal of adenomas through colonoscopy reduces colorectal cancer incidence and death, emphasizing the preventive value of diagnostic pathways that culminate in histological confirmation [3,4].

Histological categorization of colorectal polyps has direct clinical implications. Conventional adenomas (tubular, tubulovillous, and villous) carry varying malignant potential, while hyperplastic and serrated lesions are now recognized to have a distinct neoplastic pathway in selected settings, particularly in the proximal colon or when lesions are large [14]. Similarly, biopsy-based diagnosis is critical for inflammatory bowel disease, where standardized reporting supports differentiation from infectious or drug-induced colitis and facilitates longitudinal monitoring [12,13]. Recent quality-focused studies further demonstrate that colonoscopy performance indicators, such as adenoma detection rate, correlate with interval colorectal cancer risk and patient outcomes, reinforcing the need for robust diagnostic systems and pathology integration [5,6].

Although several studies have described colonoscopy biopsy spectra in different populations, institutional and regional patterns remain informative because referral pathways, symptom profiles, and access to screening can shift the case mix over time [9–11]. Against this background, the present observational study was undertaken to document the histopathological patterns of colorectal lesions in colonoscopic biopsies received at a tertiary care pathology department. The objectives of this study were to determine the age and sex distribution of patients, evaluate the anatomical distribution of lesions, describe the histopathological spectrum of colorectal lesions, and assess the histological grading pattern of colorectal adenocarcinoma.

Study design and setting

This hospital-based observational study was conducted in the Department of Pathology, RVM Institute of Medical Sciences & Research Center, Mulugu, Siddipet, Telangana, India. Colonoscopic biopsy specimens received for histopathological evaluation were assessed over the study period from January 2024 to November 2024. The study followed standard gastrointestinal pathology practices for specimen handling and reporting [13].

Sample size

A total of 100 colonoscopic biopsy specimens constituted the sample size. All samples represented patients undergoing colonoscopy for indications such as bleeding per rectum, altered bowel habits, chronic diarrhea, suspected inflammatory bowel disease, polypoidal lesions, or suspected colorectal malignancy [9,11].

Inclusion criteria

All adequately preserved colonoscopic biopsy samples from any colorectal segment (rectum, sigmoid colon, descending colon, transverse colon, and ascending colon) were included, irrespective of age and sex.

Exclusion criteria

Specimens with autolysis, gross inadequacy, severe crush artifact, or insufficient tissue for interpretation were excluded from analysis.

Specimen collection and processing

Biopsy fragments were fixed in 10% neutral buffered formalin immediately after collection. Each specimen was received with relevant clinical details and biopsy site information. Gross examination documented the number of tissue fragments and approximate size. Tissue processing included graded dehydration, clearing, and paraffin embedding using routine protocols. Serial sections of 3–5 µm thickness were obtained and stained with hematoxylin and eosin. Additional deeper levels were examined when initial sections were non-representative or when dysplasia or malignancy was suspected [13].

Histopathological evaluation and diagnostic classification

Slides were evaluated by experienced pathologists using light microscopy. Lesions were categorized as non-neoplastic or neoplastic. Non-neoplastic lesions included chronic non-specific colitis, ulcerative colitis, infectious colitis, and hyperplastic polyp. Neoplastic lesions included adenomatous polyps (tubular, tubulovillous, and villous adenoma) and adenocarcinoma. Adenomas were assessed for architectural subtype and dysplasia, in view of their established premalignant potential [7,8]. Adenocarcinomas were graded as well, moderately, or poorly differentiated based on gland formation and cytologic atypia on routine histology.

Data collection and statistical analysis

Age, sex, anatomical site of biopsy, and histopathological diagnosis were recorded in a structured proforma. Data were summarized using descriptive statistics, and categorical variables were expressed as frequency and percentage. Results were presented in tables to depict demographic distribution, lesion location, histopathological spectrum, and adenocarcinoma grading.

Ethical considerations

Institutional permission was obtained prior to commencement of the study. Patient confidentiality was maintained by de-identifying records and restricting data access to study investigators

A total of 100 colonoscopic biopsy specimens were evaluated. The results are summarized in Tables 1–4.

The age and sex distribution of the study participants is presented in Table 1. The highest proportion of cases belonged to the 51–60 years age group (28%), followed by 41–50 years and ≥61 years (22% each). Male participants constituted 58% of the cohort, indicating a modest male predominance. (Table 1).

Table 1. Age and sex distribution of study participants (N = 100)

The anatomical distribution of colorectal lesions is shown in Table 2. The rectum was the most common site of involvement (38%), followed by the sigmoid colon (26%) and the descending colon (14%). Lesions in the ascending and transverse colon accounted for 12% and 10% of cases, respectively. (Table 2).

Table 2. Anatomical distribution of colorectal lesions

The histopathological spectrum of colorectal lesions is summarized in Table 3. Non-neoplastic lesions were more frequent (56%) than neoplastic lesions (44%). Among non-neoplastic diagnoses, chronic non-specific colitis was the most common (28%), followed by ulcerative colitis (12%), hyperplastic polyp (10%), and infectious colitis (6%). Among neoplastic lesions, adenocarcinoma constituted the largest subgroup (26%), while adenomatous polyps accounted for 18% overall (tubular adenoma 12%, tubulovillous adenoma 4%, and villous adenoma 2%). (Table 3).

Table 3. Histopathological spectrum of colorectal lesions

Figure 1. Histopathological spectrum of colorectal lesions

The histological grading of adenocarcinoma (n = 26) is detailed in Table 4. Moderately differentiated adenocarcinoma was the predominant grade (53.8%), followed by well differentiated (30.8%) and poorly differentiated tumors (15.4%). (Table 4).

Table 4. Histological grading of adenocarcinoma (n = 26)

The present study evaluated 100 colonoscopic biopsies and demonstrated a broad histopathological spectrum ranging from inflammatory conditions to invasive malignancy. The peak frequency in the 51–60 years age group and the male predominance observed in this cohort are comparable to patterns described in other biopsy-based audits, where symptomatic presentation and referral-based sampling contribute to higher representation of middle-aged and older adults [9–11]. Age clustering is clinically relevant because the risk of neoplasia increases with advancing age, and careful histological assessment of suspicious lesions in this group supports earlier diagnosis and timely intervention.

In terms of anatomical distribution, lesions were predominantly distal, with rectum and sigmoid colon together accounting for 64% of cases. Several regional series have similarly reported a distal preponderance in diagnostic colonoscopy cohorts, particularly among patients presenting with bleeding per rectum or altered bowel habits [10,11]. Distal predominance also carries practical value because rectal and sigmoid lesions are readily accessible and can be sampled adequately, allowing prompt histopathological confirmation. However, the continuing emphasis on colonoscopy quality is important, since missed lesions and interval cancers are linked to procedural performance, and recognized quality indicators correlate with subsequent cancer risk [5,6].

Non-neoplastic lesions constituted 56% of diagnoses, with chronic non-specific colitis as the most frequent finding. This distribution aligns with the clinical reality that chronic diarrhea, abdominal pain, and suspected colitis constitute common indications for colonoscopy and biopsy in routine practice [9–11]. Histopathology provides value by stratifying inflammatory patterns and supporting differentiation of ulcerative colitis from other chronic inflammatory conditions. Standardized approaches to biopsy diagnosis of colitis and careful evaluation of architectural distortion, basal plasmacytosis, and activity improve diagnostic consistency and enhance clinicopathological correlation [12,13].

Neoplastic lesions formed 44% of cases, and adenocarcinoma accounted for 26% of all biopsies in the present study. This notable burden of malignancy is comparable to tertiary care series where biopsy sampling is often targeted to endoscopically suspicious masses and strict symptom-based referral results in higher malignant yield [9,10]. Most adenocarcinomas were moderately differentiated, which mirrors the typical histological grading distribution in colorectal cancer cohorts. The biological plausibility of this neoplastic spectrum is supported by the adenoma–carcinoma sequence, in which stepwise genetic alterations drive progression from benign mucosa to adenoma and invasive carcinoma [7,8]. Importantly, robust evidence indicates that colonoscopic detection and removal of adenomas reduces colorectal cancer incidence and mortality, highlighting the preventive significance of early lesion identification and histological confirmation [3,4].

Hyperplastic polyps constituted 10% of lesions in this study. Although traditionally regarded as low-risk lesions, contemporary evidence indicates that some hyperplastic and serrated lesions participate in alternative carcinogenic pathways, and their recognition has implications for surveillance planning [14]. Taken together, the present findings reinforce the central role of colonoscopic biopsy in evaluating lower gastrointestinal disease. Routine histopathological reporting that integrates lesion type, anatomical site, and tumor grade provides actionable information for clinicians and supports evidence-based management across inflammatory, premalignant, and malignant colorectal conditions.

Limitations

This study was limited by its single-center design and the fixed sample size of 100 biopsies, which restricts external validity. Detailed clinical presentation, colonoscopic impression, and medication history were not analyzed, reducing clinicopathological correlation. Ancillary investigations such as immunohistochemistry and molecular assays were not undertaken, so etiological confirmation and pathway analysis were not evaluated. Follow-up information on treatment response, recurrence, and survival was not captured

This observational study of 100 colonoscopic biopsies documented a wide histopathological spectrum of colorectal lesions in a tertiary care pathology department. Inflammatory lesions constituted the majority, with chronic non-specific colitis as the commonest diagnosis, highlighting the frequent clinical burden of chronic colitis in colonoscopy practice. Neoplastic lesions formed a substantial proportion, and adenocarcinoma was the most frequent malignant diagnosis, emphasizing the importance of early evaluation of symptomatic patients. Rectal and sigmoid predominance reinforced the need for careful distal assessment and adequate biopsy sampling. Overall, systematic histopathological reporting of colonoscopic biopsies strengthens diagnostic accuracy, supports risk stratification, and helps clinicians plan surveillance and management, including timely oncologic referral when indicated.

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