Incidental Finding of Riedel’s Lobe of the Liver and Intrahepatic Cholangiocarcinoma

Abstract

Riedel's lobe is a rare anatomical variant of the liver morphology with a downward tongue-like projection of the anterior edge of the right lobe. It is usually detected incidentally with abdominal imaging performed for other indications. We present a case where we found Riedel's lobe incidentally, with invasive adenocarcinoma arising from close proximity. A 64-year-old female came in with encephalopathy and was found to have a distended abdomen with tenderness. Imaging revealed a complex lobular mass in the right hepatic lobe with an elongated extension of the right lobe inferiorly consistent with Riedel's lobe. The differential considered was malignancy versus abscess. CT-guided biopsy revealed invasive adenocarcinoma consistent with intrahepatic cholangiocarcinoma, which was further supported by the presence of portocaval lymph nodes. Various studies have tried to establish an association between Riedel's lobe and the occurrence of cancer arising from the surrounding structures, primarily from liver or metastasis. This case report adds to the current literature when such an association is being studied.

Surgical Anatomy of the Liver—Significance in Ovarian Cancer Surgery

“…In cases of isolated metastatic lesions in Riedel's lobe, resection is a possible option [13,28]. A few cases of primary malignant tumors or metastases to Riedel's lobe have been described [32][33][34]: Soo et al reported on a Riedel's lobe metastasis from a ductal breast cancer [32]; Zamfir et al observed a case of a 65-year-old woman with primary hepatocellular Significance of Riedel's Lobe in Ovarian Cancer Surgery Riedel's lobe can be confused with an enlarged lymph node or an unidentified abdominal mass on various imaging techniques. In cases of isolated metastatic lesions in Riedel's lobe, resection is a possible option [13,28].…”

“…In cases of isolated metastatic lesions in Riedel's lobe, resection is a possible option [13,28]. A few cases of primary malignant tumors or metastases to Riedel's lobe have been described [32][33][34]: Soo et al reported on a Riedel's lobe metastasis from a ductal breast cancer [32]; Zamfir et al observed a case of a 65-year-old woman with primary hepatocellular A few cases of primary malignant tumors or metastases to Riedel's lobe have been described [32][33][34]: Soo et al reported on a Riedel's lobe metastasis from a ductal breast cancer [32]; Zamfir et al observed a case of a 65-year-old woman with primary hepatocellular carcinoma arising from her Riedel's lobe. The lobe was resected with "en-block" cholecystectomy [33].…”

“…The authors stated that there are unanswered associations between Riedel's lobe and cancer. They concluded that the lobe could be considered a possible site for primary hepatocellular carcinoma or hidden metastases [34]. Notably, the majority of cases of Riedel's lobe involvement by a malignant tumor affected the female population [32][33][34].…”

“…They concluded that the lobe could be considered a possible site for primary hepatocellular carcinoma or hidden metastases [34]. Notably, the majority of cases of Riedel's lobe involvement by a malignant tumor affected the female population [32][33][34]. However, there is no reported case in medical literature of metastases to Riedel's lobe by ovarian cancer.…”