123P - Sarcomatoid carcinoma of gall bladder: A series of 14 cases from a single tertiary-care oncology centre

Background

Gallbladder carcinoma (GBC) is a rare malignancy with an annual incidence of 1–2 cases per 100,000 persons in the United States. The aim of the study was to evaluate the frequency of sarcomatoid differentiation in GBCs and to assess their behaviour and outcomes.

Methods

A total of 2669 GBCs were screened between 2018-2022 at Tata Memorial Hospital, Mumbai, India. All the pathology material was reviewed and the diagnosis was confirmed. The presence of spindle/ pleomorphic/ anaplastic cells was considered as sarcomatoid differentiation in GBCs and were included in the analysis.

Results

A total of 14 cases of sarcomatoid GBCs were identified and analysed. The mean age was 54.7 years with a male-to-female ratio of 1.33. The most common complaints were pain in the abdomen (11/14; 78%). The mean serum CA-19.9 was 3788.2 U/ml. The mean T size was 7.27 cms. 8/14 cases were locally advanced gall bladder cancer. A total of 5/14 cases were metastatic at presentation. The most common histology was the presence of pleomorphic spindle cells (11/14; 78.5%), anaplastic cells (2/14; 14.2%) and one case showing rhabdoid morphology. Seven cases were biphasic; of which two were adenosquamous carcinoma. Lymphovascular invasion was seen in 14.2% (2/14) and perineural invasion was present in 7.1% (1/14) cases. Cytokeratin and CK7 were the most common immunohistochemistry in 42.5% (6/14) cases. The most common chemotherapy used was gemcitabine and cisplatin (5/14, 35.71%) followed by Gemcitabine and oxaliplatin (2/14, 14.2%). Two patients additionally received external beam radiotherapy (EBRT). The mean follow-up duration was 8.07 months (range of 17 days-38 months). One patient had developed brain metastasis while another developed recurrence at the port site. Most patients died of the disease in the first year after diagnosis. The overall behaviour was worse than conventional adenocarcinomas with poor survival.

Conclusions

Sarcomatoid GBC are rare aggressive neoplasms; commonly seen in older patients and at an advanced stage at presentation and poor response to conventional chemotherapy. Larger prospective studies are warranted for a better understanding of the disease.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.