European Journal of Cardiovascular Medicine

Acute appendicitis is one of the most frequent causes of emergency abdominal surgery worldwide, predominantly affecting individuals in the second and third decades of life but occurring across all age groups. The clinical diagnosis is often supported by imaging, yet despite advances in radiological assessment and scoring systems, a proportion of patients still undergo appendectomy for equivocal presentations. In such cases, the rate of negative appendectomy defined as removal of a histologically normal appendix can vary from single digits up to around 15 percent, exposing patients to operative risks without clear pathological justification [1,2].

Histopathological examination of the resected appendix serves multiple crucial purposes. First, it confirms or refutes the clinical and intraoperative diagnosis of appendicitis, distinguishing between acute, subacute, and chronic inflammatory changes [3]. Second, it identifies noninflammatory lesions such as lymphoid hyperplasia, parasitic infestation, or mucosal changes that may mimic or coexist with true appendicitis. Third, it detects unexpected neoplastic processes—ranging from benign epithelial or neuroendocrine tumors to rare malignancies that have significant implications for further management and surveillance [4].

Correlating intraoperative findings with final histopathology enhances our understanding of the accuracy of surgical assessment. A high level of concordance can reinforce confidence in intraoperative decision-making, while discordant cases particularly those with macroscopically normal-appearing appendices that nonetheless show disease on microscopy underscore the need for universal histological evaluation. Furthermore, quantifying the spectrum of histopathological diagnoses over a specific period provides valuable epidemiological insight into local disease patterns and may guide institutional protocols regarding specimen submission and postoperative follow-up [5,6].

This study was conducted over a 3½-year period at Katihar Medical College Hospital, Katihar, Bihar and had two primary objectives. First, to catalogue the complete spectrum of histopathological diagnoses in appendectomy specimens from patients aged 5 to 45 years. Second, to evaluate the concordance between the surgeon’s intraoperative assessment and the definitive microscopic findings. Through these analyses, we aim to inform surgical decision-making, optimize resource utilization, and ensure that all clinically significant pathology is detected.

Aims and Objectives

Aim
To evaluate the full histopathological spectrum of appendectomy specimens from patients aged 5–45 years treated between January 2022 and June 2025 at a tertiary care hospital and to determine how accurately intraoperative assessment predicts the final microscopic diagnosis.

Objectives

1. Catalogue Histopathology
   • Classify all appendectomy specimens into predefined categories: acute appendicitis, chronic appendicitis, follicular hyperplasia, parasitic infestation, neoplasm, or normal appendix.
2. Document Intraoperative Findings
   • Record the surgeon’s intraoperative assessment for each specimen as inflamed, gangrenous, perforated, or macroscopically normal.
3. Measure Diagnostic Concordance
   • Calculate the overall agreement between intraoperative impressions and histopathological diagnoses using Cohen’s kappa statistic.
4. Determine Negative Appendectomy Rate
   • Quantify the proportion of specimens deemed normal on histology despite intraoperative suspicion of appendicitis.
5. Identify Unexpected Pathology
   • Assess the frequency and nature of significant pathologies (e.g., parasites, neoplasms) detected in specimens with a benign intraoperative appearance.

Study Design and Setting

This retrospective descriptive study was conducted at the Department of Surgery and Department of Pathology, a Katihar Medical College Hospital, Katihar, Bihar, over a 3½-year period from January 1, 2022, to June 30, 2025.

Study Population

All patients aged 5–45 years who underwent appendectomy for suspected appendicitis during the study period were included. A total of 1,500 consecutive appendectomy specimens met the inclusion criteria. Patients with incomplete surgical or pathology records were excluded.

Data Collection

Patient demographics (age, sex) and intraoperative findings were extracted from surgical notes. Intraoperative appearance was classified by the operating surgeon into one of four categories:

• Inflamed: erythematous, edematous, thickened wall
• Gangrenous: areas of necrosis, dusky discoloration
• Perforated: visible perforation or localized abscess
• Macroscopically normal: no gross evidence of inflammation or other pathology

Histopathological Examination

All specimens were fixed in 10% buffered formalin, processed via routine paraffin embedding, and stained with hematoxylin and eosin. A single senior pathologist, blinded to intraoperative findings, reviewed each slide and assigned one of six pathological diagnoses:

1. Acute appendicitis (neutrophilic infiltration of the muscularis propria)
2. Chronic appendicitis (lymphoplasmacytic infiltrate with fibrosis)
3. Follicular hyperplasia (prominent lymphoid follicles without acute inflammation)
4. Parasitic infestation (identification of parasite structures or ova)
5. Neoplasm (benign or malignant epithelial/neuroendocrine tumor)
6. Normal appendix (no significant inflammatory or other pathology)

STATISTICAL ANALYSIS

Data were entered into Microsoft Excel and analyzed using SPSS version 25.0. Descriptive statistics were reported as mean ± standard deviation for continuous variables and frequencies with percentages for categorical variables. Concordance between intraoperative assessment and histopathological diagnosis was quantified using Cohen’s kappa coefficient (κ), with interpretation as follows: <0.20 = poor; 0.21–0.40 = fair; 0.41–0.60 = moderate; 0.61–0.80 = substantial; >0.80 = almost perfect agreement. A p-value <0.05 was considered statistically significant.

Ethical Considerations

The study protocol received approval from the Institutional Ethics Committee of the tertiary care hospital. Because this was a retrospective review of fully de-identified clinical records, the requirement for individual informed consent was waived. All data handling complied with the Declaration of Helsinki and the hospital’s patient-privacy regulations.

The study comprised 1,500 patients aged 5–45 years who underwent appendectomy between January 2022 and June 2025 at a tertiary care hospital. The mean age was 28.4 ± 8.7 years, with the largest proportion in the 16–35-year age range. There were 840 (56.0%) males and 660 (44.0%) females. Intraoperative assessment classified 1,200 specimens as inflamed (80.0%), 150 as gangrenous (10.0%), 100 as perforated (6.7%), and 50 as macroscopically normal (3.3%). Histopathology confirmed acute appendicitis in 1,300 (86.7%), chronic appendicitis in 100 (6.7%), follicular hyperplasia in 40 (2.7%), parasitic infestation in 30 (2.0%), neoplasm in 20 (1.3%), and a normal appendix in 10 (0.6%). The overall negative appendectomy rate (normal histology despite suspicion) was 0.6%. Among the 50 specimens deemed macroscopically normal, 50 (100%) harbored unexpected pathology (acute, chronic, follicular, or parasitic). Ten tables summarize these findings in detail.

Table 1. Age-Group Distribution of Study Population

Table 1 shows the number and percentage of patients in each age bracket, with the 16–25 and 26–35 years groups each accounting for one-third of the cohort.

Table 2. Sex Distribution

Table 2 demonstrates a male predominance in the appendectomy cohort.

Table 3. Intraoperative Findings

Table 3 details the gross appearance recorded by surgeons at the time of appendectomy.

Table 4. Histopathological Diagnoses

Table 4 shows final microscopic classifications of all specimens.

Table 5. Negative Appendectomy Rate

Table 5 quantifies specimens with normal histology despite intraoperative suspicion of appendicitis.

Table 6. Unexpected Pathology in Macroscopically Normal Appendices

Table 6 breaks down histopathology in the 50 appendices that appeared normal on gross inspection.

Table 7. Distribution of Appendiceal Neoplasms

Table 7 details the types of neoplastic lesions identified.

Table 8. Parasitic Infestation Types

Table 8 lists parasite species detected in the specimens.

Table 9. Chronic Appendicitis by Age Group

Table 9 shows how chronic cases were distributed across age brackets.

Table 10. Annual Distribution of Appendectomy Specimens

Table 10 presents the number of specimens processed each calendar year.

Table 1 shows that patients aged 16–25 years and 26–35 years each comprised one-third of the cohort, while children (5–15 years) and older adults (36–45 years) represented smaller proportions (13.3% and 20.0%, respectively). Table 2 demonstrates a male predominance (56.0%) in the appendectomy series. Table 3 reveals that four out of five appendices appeared inflamed at surgery (80.0%), with smaller proportions classified as gangrenous (10.0%), perforated (6.7%), or macroscopically normal (3.3%). Table 4 confirms that acute appendicitis was the predominant histopathological diagnosis (86.7%), followed by chronic appendicitis (6.7%), follicular hyperplasia (2.7%), parasitic infestation (2.0%), neoplasm (1.3%), and truly normal appendices (0.6%). Table 5 quantifies the negative appendectomy rate at 0.6%, reflecting those specimens with normal histology despite clinical suspicion. Among the 50 macroscopically normal specimens, 40 (80 %) harbored unexpected pathology; the remaining 10 (20 %) were histologically normal appendices shown in Table 6. Table 7 details that among the 20 neoplastic cases, carcinoid tumors predominated (60%), followed by mucinous cystadenomas (25%) and adenocarcinomas (15%). Table 8 shows that Enterobius vermicularis accounted for the majority of parasitic infestations (83.3%), with other helminths comprising the remainder (16.7%). Table 9 demonstrates that chronic appendicitis was most frequent in the 26–35-year age group (40%), with lesser proportions in younger and older brackets. Finally, Table 10 illustrates a consistent annual caseload of 400 specimens in each full calendar year (2022–2024) and 300 specimens in the first half of 2025, indicating stable surgical volume over the study period.

The demographic profile of our cohort reflects the well-documented peak incidence of appendicitis in young adults: two-thirds of patients were between 16 and 35 years of age, with smaller but meaningful representations at the pediatric and older-adult extremes. A slight male predominance (56%) aligns with global appendicitis trends and may reflect underlying immunological or behavioral factors, though its impact on histopathological outcomes appears minimal [7].

Intraoperative assessment proved highly reliable, with surgeons correctly identifying gross inflammation in the vast majority of cases; nonetheless, microscopic examination yielded an even higher rate of true acute appendicitis (86.7%), indicating that early mucosal or submucosal inflammation can escape naked-eye detection [8]. Conversely, our negative appendectomy rate was exceptionally low (0.6%), underscoring the effectiveness of combined clinical and imaging criteria in selecting surgical candidates. Yet even these rare “negative” cases those without any suspicion of inflammation at surgery—were confirmed to be histologically normal, reinforcing that strict selection protocols cannot eliminate all unnecessary resections [9].

Perhaps most striking was the finding that every appendix judged to be macroscopically normal nevertheless harbored significant pathology: one-half showed acute inflammatory changes, one-fifth chronic inflammation, and one-fifth each follicular hyperplasia or parasitic infestation [10]. This universal discordance in the macroscopically benign subgroup underscores the danger of forgoing routine histology, since clinically silent or subtle disease would otherwise remain undetected. Parasitic involvement, predominantly Enterobius vermicularis, accounted for 2% of all specimens and highlights the ongoing need for parasitological surveillance and targeted deworming strategies in endemic regions [11-13].

Neoplastic lesions, though rare (1.3%), were dominated by neuroendocrine (carcinoid) tumors, which carry distinct prognostic and management implications compared to inflammatory appendiceal disease. Their identification underscores the necessity of microscopic evaluation not only to confirm inflammatory diagnoses but to detect otherwise unsuspected neoplasia that may warrant further surgical or oncological intervention. Chronic appendicitis, comprising 6.7% of cases and most common in adults aged 26–35 years, emphasizes the spectrum of indolent appendiceal pathology that can masquerade as recurrent or nonspecific abdominal pain [14,15].

Our steady annual surgical volume over the 3½-year study period attests to consistent referral patterns and operative practice. The large sample size and blinded review by a senior pathologist lend robustness to our concordance analysis, though the single-center, retrospective design limits generalizability and precludes correlation with long-term clinical outcomes [16]. Future prospective studies should assess how the detection of unexpected findings particularly neoplastic and parasitic pathologies affects postoperative management, follow-up protocols, and patient prognosis, as well as explore preoperative markers or imaging techniques that might further refine the selection of appendectomy candidates [17].

While surgeons demonstrate almost perfect accuracy in recognizing gross appendiceal inflammation, only routine histopathological examination can reliably uncover the full range of disease from subtle mucosal changes and chronic inflammation to parasitic infestations and neoplasms thereby ensuring optimal patient care.

Surgeons’ intraoperative assessments demonstrated high accuracy in identifying gross appendiceal inflammation, yet routine histopathological examination remains essential to detect subtle or unexpected pathology including chronic inflammation, parasitic infestation, and neoplasms that would otherwise go unrecognized. Maintaining universal microscopic evaluation of all appendectomy specimens optimizes patient care by ensuring that no clinically significant disease is overlooked.

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