Pathological Appearance of Focal Liver Reactions after Radiotherapy for Hepatocellular Carcinoma
Masahiro Okada,
Kazushi Numata,
Hiromi Nihonmatsu,
Kengo Tomita,
Atsuya Takeda,
Kenichiro Tago,
Tomoko Hyodo,
Takahisa Eriguchi,
Masayuki Nakano
Affiliations
Masahiro Okada
Department of Radiology, Nihon University School of Medicine, Itabashi-ku, Tokyo 173-8610, Tokyo, Japan
Kazushi Numata
Gastroenterological Center, Yokohama City University Medical Center, 4-57 Urafune-cho, Minami-ku, Yokohama 232-0024, Kanagawa, Japan
Hiromi Nihonmatsu
Gastroenterological Center, Yokohama City University Medical Center, 4-57 Urafune-cho, Minami-ku, Yokohama 232-0024, Kanagawa, Japan
Kengo Tomita
Division of Gastroenterology and Hepatology, Department of Internal Medicine, National Defense Medical College, 3-2 Namiki, Tokorozawa-shi 359-8513, Saitama, Japan
Atsuya Takeda
Radiation Oncology Center, Ofuna Chuo Hospital, 6-2-24, Ofuna, Kamakura 247-0056, Kanagawa, Japan
Kenichiro Tago
Department of Radiology, Nihon University School of Medicine, Itabashi-ku, Tokyo 173-8610, Tokyo, Japan
Tomoko Hyodo
Department of Radiology, Kindai University Faculty of Medicine, 377-2 Ohno-Higashi, Osaka-Sayama 589-8511, Osaka, Japan
Takahisa Eriguchi
Radiation Oncology Center, Ofuna Chuo Hospital, 6-2-24, Ofuna, Kamakura 247-0056, Kanagawa, Japan
Masayuki Nakano
Department of Pathology, Yokohama City University Medical Center, 4-57 Urafune-cho, Minami-ku, Yokohama 232-0024, Kanagawa, Japan
We studied five pathological specimens from five patients at 1.5, 3.0, 4.0, 13.5, and 14.0 months after radiotherapy for HCC. Four needle biopsies were obtained to investigate liver parenchyma of focal liver reaction (FLR) around treated HCC, when patients had newly developed HCC or local recurrence appeared in the liver. Liver resection was performed in one case where insufficient radiotherapy effect for HCC was suspected. In all patients, FLR was recognized as a hypervascular area around the HCC on enhanced CT and enhanced Gd-EOB-DTPA (EOB-MRI). Liver specimens were analyzed to assess the pathological characteristics of FLR. FLR was recognized as prolonged liver enhancement in enhanced CT and EOB-MRI. From pathological understanding, sinusoidal dilatation with degeneration and desquamation was caused by direct endothelial cell injury following radiotherapy. Hepatocytes and endothelium fell off, and so the portal tract came close, and hepatic arteries increase simultaneously, resulting in FLR around HCC after radiotherapy. In conclusion, the prolapse of hepatocytes and sinusoidal endothelium induced neovascularization of hepatic arteries due to the repair mechanisms; in addition, these prolapse may shorten the distance between each portal region and the hepatic arteries flowing through the portal region become more prominent in FLR.
