Rare case of an ovarian vein tumor thrombosis identified on fluorodeoxyglucose positron emission tomography/computed tomography.

Fludeoxyglucose positron emission tomography/computed tomography is valuable in the identification of tumor thrombus and differentiating it from bland thrombus which has implications in initiating anticoagulation. We present a rare case of tumor thrombosis in ovarian vein, in a recurrent case of uterine carcinosarcoma.

A 50-year-old female, an operated case of carcinosarcoma uterus (3 months ago), presenting with increased abdominal pain, underwent positron emission tomography/computed tomography (PET/CT) for evaluation of suspicious disease recurrence. Maximum intensity projection images [Figure 1a] showed intense fludeoxyglucose (FDG) uptake in the pelvis with linear intense FDG uptake extending from the right pelvis up to the renal hilum and another linear, intense FDG uptake in the mid abdomen medial to it. Coronal FDG PET fused PET/CT [Figure 1b] image in the pelvis showed FDG avid recurrent disease in the right side of pelvis and tumor thrombus in bilateral internal iliac veins (white arrows). Coronal fused FDG-PET/CT [Figure 2a] and contrast enhanced CT [Figure 2b] of the abdomen showed linear FDG uptake in the enlarged right ovarian vein (bold white arrow) and physiological uptake in the left ureter medial to it (thin white arrow). Sagittal fused FDG PET/CT [Figure 2c] image of abdomen showed anterior relation of the ovarian vein tumor thrombus to the psoas muscle posteriorly. Transaxial fused PET/CT [Figure 2d] images show the proximal opening of the ovarian vein with tumor thrombus into the inferior vena cava (white arrowhead). Additional FDG avid metastatic lesions were noted in the enlarged pelvic nodes, sacrum, and upper lobe of the right lung (not shown above).

Figure 1

Maximum intensity projection image (a) showed intense FDG uptake in the pelvis with linear intense FDG uptake extending from the right pelvis up to the renal hilum and another linear intense FDG uptake in the mid abdomen medial to it. Coronal FDG PET fused PET/CT (b) image in the pelvis showed FDG avid recurrent disease in the right side of pelvis and tumor thrombus in bilateral internal iliac veins (white arrows). FDG: Fludeoxyglucose; PET: Positron emission tomography; CT: Computed tomography

Figure 2

Coronal fused FDG PET/CT (a) and contrast enhanced CT (b) of the abdomen showed linear FDG uptake in the enlarged right ovarian vein (bold white arrow) and physiological uptake in the enlarged left ureter medial to it (thin white arrow). Sagittal FDG PET/CT (c) image of abdomen showed the anterior relation of the ovarian vein tumor thrombus to the psoas muscle posteriorly. Transaxial FDG PET/CT (d) images show the proximal opening of the ovarian vein with tumor thrombus into the inferior vena cava (white arrowhead). FDG: Fludeoxyglucose; PET: Positron emission tomography; CT: Computed tomography

Ovarian vein thrombosis (OVT) is a rare condition, usually seen in postpartum period and predisposes patient at risk for fatal pulmonary thromboembolism.[12] Other causes are debulking pelvic surgeries, pelvic inflammatory diseases, and malignancies.[34] The recognition of this entity is important as it has been seen that survival is better in OVT in patients with cancer, compared to these patients without cancer.[4] Unlike OVT in the postpuerperial setting, the OVT associated with malignancies can be asymptomatic and usually detected incidentally on imaging.

Usual methods of imaging OVT include ultrasonography, magnetic resonance imaging and multidetector computed tomography (MDCT). Identifying normal ovarian vein on CT may be difficult. It usually originates from the broad ligament near the ovary; communicate with uterine plexus, runs anterior to psoas muscle/ureter, and drains into inferior vena cava (on right) or left renal vein (on left). Identification of the ovarian vein is useful in imaging gynecological cancers as it helps to ascertain the origin of the mass whether it arises from adnexa or not.[5] On MDCT, the OVT appears to be a filling defect within ovarian vein, which may or may not be enlarged. On coronal reconstruction, this appears like a tubular structure in the retroperitoneum.[6]

With increasing use of FDG PET/CT in various gynecological malignancies, incidental observation of tumor thrombosis on PET/CT is not uncommon.[7] In addition to diagnosing thrombus, PET/CT helps in differentiating nonmetabolically active bland thrombus from metabolically active tumor thrombus which can have treatment implications with respect to anticoagulation. There is no strong evidence currently to suggest routine anticoagulation in patients with tumor thrombus as these resolve spontaneously.[4] Identification of OVT on FDG PET/CT to our knowledge has been reported only once in literature.[8] This case re-illustrates the potential clinical utility of PET/CT in imaging tumor thrombus.

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Conflicts of interest

There are no conflicts of interest.