Teaching Case

A 68-year-old female with a history of breast cancer was admitted for follow-up CT scan.

Previous CT scan revealed filling defects - consistent with acute thrombosis - in the left internal jugular and brachiocephalic veins and in the superior vena cava surrounding the Central Venous Catheter (CVC) placed for chemotherapy (Fig. 1).

Current CT scan showed severe narrowing - consistent with chronic thrombosis - of the left internal jugular and brachiocephalic veins and of the superior vena cava surrounding the CVC (Fig. 2); in this context, it also portrayed extensive venous collateral pathways involving the left internal mammary and paraumbilical venous systems (Fig. 3), ultimately resulting in a hypervascular geographic area in the hepatic segment IVb, the so-called “quadrate lobe focal hot spot sign” (Fig. 4).

The “quadrate lobe focal hot spot sign” is an Imaging finding identifiable by contrast-enhanced CT or technetium 99m (99mTc) sulfur colloid scans; it involves the medial segment of the left hepatic lobe (previously known as the quadrate lobe), appearing in contrast-enhanced CT scans as a hypervascular area [1,2].

It classically results from portosystemic venous shunting involving internal mammary and paraumbilical veins, occurring secondarily to thoracic/central venous obstruction, most commonly involving the superior vena cava [1,3].

As a main “teaching point”: if you identify the “quadrate lobe focal hot spot sign”, look carefully for a thoracic/central venous obstruction.

Written informed patient consent for publication has been obtained.