A rare case of the left colic vein and sigmoid vein draining into the left ovarian vein: a case report.

During routine cadaveric dissection of an 83-year-old female cadaver, an unusual venous pattern was observed on the left side of the abdominal cavity. Two previously undescribed tributaries, identified as the sigmoid vein and the left colic vein, were found draining directly into the left ovarian vein (LOV). The sigmoid vein measured 57.46 mm in length and 0.43 mm in diameter, while the left colic vein measured 54.61 mm in length and 5.14 mm in diameter. The LOV itself exhibited marked dilatation, reaching a maximum diameter of 19.19 mm before entering the suspensory ligament of the ovary. Despite the presence of these anomalous tributaries, the LOV maintained a typical anatomical course and drained into the left renal vein. No signs of previous surgical intervention or pathology were noted in the abdominal region. The diameters of all the aforementioned veins, including the hepatic portal vein, left renal vein, and left suprarenal vein, were measured with calipers at the widest points along their course. Before the measurements were taken, it was ensured that the condition of the veins minimized measurement error by avoiding bending, flattening, or unnatural stretching. Measurements were performed twice by two independent observers, and the average value was calculated. This case represents a rare anatomical variation with potential clinical relevance, particularly in the context of pelvic congestion syndrome, retroperitoneal surgery, or diagnostic imaging.