Gallbladder carcinoma is the 5^th most common cause of gastrointestinal tract¹  globally. In india the incidence of gallbladder carcinoma is 0.8%-1%².  The risk factors are cholelithiasis , calcified gallbladder wall, adenomatous polyp, obesity, estrogen ,choledochal cyst and chemical carcinogens^2,3 cholecystectomy is the most common surgical procedure for chronic cholecystitis and gallbladder cancer.^4,5

Incidental gallbladder carcinoma is the incidental finding of carcinoma in histopathological examination of gallbladder specimen after cholecystectomy done for benign gallbladder disease².

Incidental gallbladder carcinoma also known as occult / inapparent/ missed gallbladder carcinoma⁶ and patients do not have a radiological or intraoperative suspicious of malignancy^7,8

AIMS AND OBJECTIVES

1. To study age wise and sex wise analysis of gallbladder lesions
2. To determine the pathological staging of Incidental gallbladder carcinoma

MATERIALS AND METHODS

A Retrospective (3yrs) study was done on abdominal and laparoscopic cholecystectomies with a clinical, radiological diagnosis of benign gallbladder lesions at Santhiram medical college and general hospital, Nandyal during the period from Jan 2021 to Dec 2023. A total of 684 cholecystectomy specimens were received. The specimens were fixed in 10% formalin, routine processing was done , Hematoxylin & Eosin stained sections were microscopically examined  and Incidental gallbladder carcinoma diagnosis was confirmed.

The pathological staging was done according to American Joint Committee of cancer gallbladder cancer staging (8^th edition). The case details like age, sex, presence of stones and radiological CT and USG findings were taken from the hospital records . The data analysed by using SPSS version 21.0 software programme. Ethical committee (IEC) clearence was taken prior to the study.

Inclusion criteria

Abdominal and laproscopic cholecystectomy specimen

Exclusion criteria

Diagnosed or suspected cases of gallbladder carcinoma

RESULTS

Table 1:Sex wise distribution  of Gallbladder lesions

Table 2:Age and sex wise distribution of  Gallbladder lesions

Table 3:Incidence of Benign and Malignant lesions of Gallbladder

Table 4: Incidence of Incidental Gallbladder carcinoma among male and females in Gall bladder lesions

Table 5:Age and sex wise distribution of incidence of Incidental Gallbladder carcinoma in  lesions of gall bladder .

Table 6: Gross findings of Incidental gall bladder carcinoma

Table 7: Histopathological features of Incidental Gallbladder Carcinoma

Table 8: Pathological staging of Incidental Gallbladder carcinoma

Table 9: Comparison of Incidence rates in different studies.

FIGURES:

Figure 1 : Well differentiated adenocarcinoma of Gallbladder - high power view (H & E )

Figure 2: Moderately differentiated adenocarcinoma of gallbladder – high power view (H& E)

684 cases of cholecystectomy specimens received over a period of 3 years. The most common lesion was calculous cholecystitis 420 cases (61.40%), following 240 cases were acalculous cholecystitis (36.26%) and 16  cases(2.34%) were Xanthogranulomatous cholecystitis. The mean age noted was 41.6 year (age range of 30-60 years)(Table 1&2).

The male to female ratio of 1:3. The most common presenting symptom was pain in the right hypochondrium in 90% of patients, followed  by nausea , vomitings(8%) and epigastric pain (4%).

Among 684 cases, 12 cases (1.75%) diagnosed as Incidental gallbladder carcinoma. All these cases were studied based on preoperative imaging findings and pathological TNM staging was done ⁹. Out of 12 cases of Incidental gallbladder carcinoma 8 cases (66.7%) cases observed with chronic calculous cholecystitis (66%), 3 cases in chronic acalculous cholecystitis (25.5%) and one case in Xantho- granulomatous cholecystitis (8.3%). Majority of cases Incidental gallbladder carcinoma observed in 9 cases(75%) in females and 3 cases(25%) in males. The age range noted was 31-60 year in females and 41-60 year in male(Table 3,4 &5).

Preoperative USG detected increased wall thickness (>3mm) in 8 cases(66.7%) and without intraluminal mass 4 cases less than 3mm in total 12 cases(33.3%). Gross inspection of majority of specimens revealed thickening of gallbladder wall in 8(66.7%).Out of  12 cases, 6 (50%) cases revealed mucosal ulceration (Table 6).

Majority of cases of Incidental gallbladder carcinoma 8/12 were associated with gallstones and histologically shown Adenocarcinoma,lymphovascular invasion 6/12(50%) and perineural invasion was seen in 1 case(8.3%).Histological grade G2(moderately differentiated) was seen in 8 cases (66.7%)(Figure 2)Incidental gallbladder carcinoma grade G1(well differentiated) (Figure 1) and grade G3 (poorly differentiated)were seen in 3 cases and 1 case. Out of 12 cases of Incidental gallbladder carcinoma one case was positive for lymphnode metastasis (Table 7).

Tumour cell infiltration noted up to lamina propria (pT1a) 2 cases (16.7%) muscularis propria in 3 cases(pT1b), tumour cells invaded beyond perimuscular connective tissue            ( p T2)6(50%) , and serosa (pT3) in 1 case  (8.3%)(Table 8).

DISCUSSION

The Incidental gallbladder carcinoma following cholecystectomy for benign diseases was noted as low (0.73%)¹⁰ .   The early stage of gallbladder carcinoma is diagnosed incidentally because the symptoms overlapse with co existent cholecystitis or cholelithiasis

The characteristics such as thickening of wall, intraluminal polypoid mass, CBD and pericholecystic collection are not hallmark of gallbladder carcinoma, even they can be present in cholecystitis⁹ .

The incidence of incidental gallbladder carcinoma  reported to be 0.2%-2.1%^17,18,19.  Incidence  was less in Daphna et al²⁴ (0.3%),it was even higher as shown by Shigeki et            al ²⁷(4.7%). Gayatri Devi et al ²⁰ ,Morera et al  ²⁶, R Shrestha et al ⁴,Amanullah et al ²⁵ shown 0.46%,1.1%,1.4% and 1.9%.Our study  differ with above authors and  consistent with Mistry et al⁹ (1.75%)(Table 9).

Incidental gallbladder carcinoma more common in female 9 cases(75%). Study correlated with Pyo et al 2020¹² , Emmett et al 2009¹³, Jha V etal 2016¹⁴. Singh et al 2020¹⁵  and Sarbjith Mohapatra et al2024¹⁰

In the present study the mean age at diagnosis was around  45.4 years correlates with Lund gren et al 2014¹¹, not correlated with vibhor jain et al ¹⁶.

Incidental gallbladder carcinoma more common in females (1:3) comparable with Gayatri Devi et al 2019 ²⁰. Majority of cases of incidental gallbladder carcinoma  are associated with cholelithiasi^21,22,23.

In the present study 8 cases (66.7%) of incidental gallbladder carcinoma  noted with cholelithiasis. Vidhya jha et al²  2018(70%), Waghmare RS et al and kamat KN et al 2014⁷(85%)  of incidence incidental gallbladder carcinoma   with gallstones. Our study correlated with the above authors study.

  In the present study well differentiated carcinoma were 3 cases(25%) G1,Moderately differentiated  carcinoma were 8 cases (66.77) G2, and poorly differentiated carcinoma was one case (8.3%) G3. Our study correlated with Gayatri Devi et al 2019 ²⁰and Wagh mare RS et al 2014⁷ .

In the present study out of 12 cases 2 cases were pT1a (2 Well differentiated), 3 cases of pT1b (1 Well differentiated & 2 moderately differentiated). pT2 were 6 cases (moderately differentiated) and one case of pT3(poorly differentiated). The staging of the disease is most important prognostic factor for patient survival (Table 8).

CONCLUSION

1. Gall bladder cancers are the most common malignancy of GIT
2. In our study the incidence of incidental gall bladder carcinoma is 1.75%
3. Cholelithiasis, especially Asymptomatic cases, should not be taken lightly as it may harbor an occult malignancy . Histopathological examination of cholecystectomy specimens is mandatory for early detection and prompt management of occult malignancy.

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