Residency Program - Case of the Month

Answer:

Radiation injury related to the decedent’s treatment for ovarian carcinoma.

Discussion:

The significant finding on autopsy was a necrotic fistula track between the distal colon and the left external iliac artery with fibrosis of the surrounding soft tissues surrounding the arteries. These findings were suspicious for radiation injury. Three areas of perforation were found in close association around the rectocolon anastomosis; one just above, one just below, and one along the suture line; all three communicated with the fistula tract. Multiple hemostasis clips were present within the area. Microfoci of malignant cells consistent with her history of ovarian carcinoma were identified within lymphoid and fibrous tissue around the iliac artery. However, no malignant cells were found along the fistula track or in the bowel sections. The soft tissues surrounding the fistula track around the arteries exhibited cellular atypia consistent with radiation injury.

Ovarian cancer is the most common cause of cancer death from gynecologic tumor in the United States. It can spread by local extension, lymphatic invasion, intraperitoneal implantation, hematogenous dissemination, and transdiaphragmatic passage. Intraperitoneal dissemination is the most common and recognized characteristic of ovarian cancer.

Ionizing radiation leads to the destruction of well-formed and stable bonds within a cell or tissue. The deformation of these bonds leads to unpaired atoms. The unstable units act like free radicals in the body, which leads to further damage within the cell, tissue or organ. These free radicals wreak havoc, leaving a wake of destruction by stealing atoms from other stable structures throughout the body. The radiation therapy the decedent received in the area most likely created a compensatory hypertrophy and abolishment of small fiber formation leading to a fibrotic area.

Radiation injury and adhesions related to the treatment for the decedent’s ovarian carcinoma laid the foundation for the formation of a fistula to develop between her rectum and iliac artery. The microfoci of ovarian carcinoma found around the iliac artery appear to represent residual nests of cancer cells following completion of the radiation therapy and were not directly responsible for the formation of the fistula.

References:

1. Fleischer A. Ovarian cancer. In: Fleischer AC, Javitt MC, Jeffrey RB Jr, et al. Clinical Gynecologic Imaging. Philadelphia, Pa: Lippincott Williams & Wilkins; 1996:107.

2. Tangjitgamol S, Manusirivithaya S, Laopaiboon M, Lumbiganon P. Interval debulking surgery for advanced epithelial ovarian cancer. Cochrane Database Syst Rev. Jan 21 2009; CD006014.

 3. Armstrong, D. "Ovaries and fallopian tubes." In: Abeloff MD ed. Abeloff's Clinical Oncology, 4th ed. Philadelphia: Churchill Livingstone; 2008: 1827-50.