# Complete regression of intrahepatic cholangiocarcinoma after right portal vein ligation. Case report

## TL;DR

A patient with intrahepatic cholangiocarcinoma experienced complete tumor regression after right portal vein ligation, a rare occurrence in oncology.

## Contribution

This is the first reported case of complete regression of intrahepatic cholangiocarcinoma following portal vein ligation.

## Key findings

- Portal vein ligation led to significant tumor regression within 5 weeks.
- No viable malignant cells were found after a second surgery, confirming complete regression.
- This case expands the understanding of rare spontaneous tumor regression in cholangiocarcinoma.

## Abstract

Spontaneous tumor regression is an extremely rare phenomenon in the oncology field.

We present the case of a 72-years-old male patient presenting with a bulky hepatic tumor mass located in segment V and extending into segments IVb and VI with MRI features of atypical cholangiocarcinoma with a liver metastasis in segment III. In first surgical step, excision of the metastasis, and ligation of the right portal vein was done. A new MRI examination performed 5 weeks later shows significant tumor regression, and 2 weeks later, during the second surgery, the tumor was not found. Under these conditions we performed a limited segment V liver resection, in the area indicated by the radiologist as the site of the tumor. No viable malignant cells existed in the tumor specimen, and a third MRI examination didn't identify any residual tumor.

From our literature study this is the only case of complete tumor regression of an intrahepatic cholangiocarcinoma following portal vein ligation. We believe the portal vein ligation resulted in a marked regression/deficiency in the tumor blood supply.

Serial MRI examinations demonstrated the regression of intrahepatic cholangiocarcinoma after portal vein ligation. Intrahepatic cholangiocarcinoma should be included in the tumors that could extremely rarely spontaneously regress.

•Spontaneous tumor regression is an extremely rare phenomenon in oncology and thus, we present a case of a right liver lobe tumor with imaging features of atypical cholangiocarcinoma with a single left lobe metastasis that disappeared after right portal vein ligation.•We decided to approach the case based on a two-stage hepatectomy. The first surgical step was metastasectomy and right portal vein ligation.•To our surprise, at the 5th week follow-up, the primary tumor significantly reduced, without any adjuvant specific chemotherapy.•Given these conditions, we performed a limited segment V resection, and neither the histopathology report, nor the follow-up MRI examination identified any residual tumor.

Spontaneous tumor regression is an extremely rare phenomenon in oncology and thus, we present a case of a right liver lobe tumor with imaging features of atypical cholangiocarcinoma with a single left lobe metastasis that disappeared after right portal vein ligation.

We decided to approach the case based on a two-stage hepatectomy. The first surgical step was metastasectomy and right portal vein ligation.

To our surprise, at the 5th week follow-up, the primary tumor significantly reduced, without any adjuvant specific chemotherapy.

Given these conditions, we performed a limited segment V resection, and neither the histopathology report, nor the follow-up MRI examination identified any residual tumor.