+Model
ARTICLE IN PRESS
CLINRE-574; No. of Pages 2
Clinics and Research in Hepatology and Gastroenterology (2014) xxx, xxx—xxx
Available online at
ScienceDirect www.sciencedirect.com
IMAGE OF THE MONTH
Hepatic hot spot sign: Beacon of SVC obstruction Shivani Pahwa a, Chandan J. Das a,∗, Sanjay Sharma a, Arun Kumar Gupta a, Aparajit Ballav Dey b a b
Department of Radiodiagnosis, All India Institute of Medical Sciences, 110029 New Delhi, India Department of Geriatric Medicine, All India Institute of Medical Sciences, 110029 New Delhi, India
Case summary A 65-year-old male patient presented with complaints of vague abdominal pain and malaise for six months. Contrastenhanced computed tomography (CECT) of the abdomen revealed a sharply demarcated, intensely enhancing area in the quadrate lobe of liver (Fig. 1A, arrow) and tortuous thoracic and abdominal wall collaterals (Fig. 1B, arrow). This constellation of findings is highly specific for superior vena cava (SVC) obstruction. The enhancing area in liver (‘‘hepatic hot spot’’) may look like a mass, but arises due to development of porto-systemic shunting in SVC obstruction. CECT chest was performed to determine the cause of obstruction. It revealed a mass in upper lobe of right lung, with the tumor thrombus completely occluding the SVC (Fig. 1C, arrow) — biopsy revealed squamous cell carcinoma. The patient was managed by placing an endovascular bare stent bypassing the malignant obstruction.
Discussion Focally increased uptake of radionuclide in liver on 99m Tc sulfur colloid scans due to opening up of collateral
∗ Corresponding author. Tel.: +91 90 13217076; fax: +91 11 26588663. E-mail address: [email protected] (C.J. Das).
pathways in superior vena cava obstruction was first described by Holmquist and Burdine [1]. Thoracic malignancies (bronchogenic carcinoma, lymphoma, metastases) are responsible for up to 85% cases of SVC obstruction [4]. Benign causes contribute to about 15% of cases and are mostly iatrogenic, due to invasive vascular access devices for chemotherapy, hyperalimentation, infusion of fluids, or due to invasive monitoring devices like pacemaker electrodes, and catheters for central venous pressure monitoring [2]. Less commonly, conditions like mediastinal fibrosis, infections, sarcoidosis, aortic aneurysms, and radiation fibrosis can cause occlusion of the SVC. Complete SVC obstruction can open up four major collateral pathways depending upon the level of obstruction: • • • •
the azygos-hemiazygos pathway; the internal and external mammary pathway; the lateral thoracic pathway; and the vertebral pathway [3].
Apart from these major collaterals, unusual cavoportal, intrahepatic, and systemic-to-pulmonary venous collaterals are seen infrequently [4]. An intensely enhancing area — the ‘‘hot spot’’ — is seen in the quadrate lobe (segment IV) of liver due to the development of cavoportal collaterals [4—6]. The superior and inferior epigastric veins communicate with the internal mammary vein. These veins drain into a recanalised paraumbilical vein, which in turn empties into the left portal vein. Internal mammary vein may also
http://dx.doi.org/10.1016/j.clinre.2014.03.008 2210-7401/© 2014 Elsevier Masson SAS. All rights reserved.
Please cite this article in press as: Pahwa S, et al. Hepatic hot spot sign: Beacon of SVC obstruction. Clin Res Hepatol Gastroenterol (2014), http://dx.doi.org/10.1016/j.clinre.2014.03.008
+Model CLINRE-574; No. of Pages 2
ARTICLE IN PRESS
2
S. Pahwa et al.
Figure 1 A. Axial contrast-enhanced computed tomography (CECT) image of the abdomen depicts a sharply demarcated, intensely enhancing area — ‘‘the hot spot’’ — in segment IV of liver (arrow). B. Shaded surface display (SSD) image illustrates the cavoportal collaterals in the thoracic and abdominal wall. C. Coronal CECT image demonstrates a mass in the upper lobe of right lung, with tumor thrombus completely occluding the superior vena cava (SVC) (arrow) — biopsy revealed squamous cell carcinoma.
drain into the inferior phrenic vein, which communicates with the portal vein tributaries through the hepatic capsular veins. The ‘‘hot spot’’ sign is not seen frequently because development of azygos-hemiazygos circulation is much more common. The hepatic ‘‘hot spot’’ on a contrast-enhanced CT should not be confused with a liver mass and its presence should prompt the search for underlying SVC obstruction. SVC obstruction can be managed through endovascular route with placement of a stent bypassing the obstruction. This is the first line, palliative management option that rapidly improves symptoms [6,7].
Disclosure of interest The authors declare that they have no conflicts of interest concerning this article.
References
[2] Kee ST, Kinoshita L, Razavi MK, Nyman OU, Semba CP, Dake MD. Superior Vena Cava Syndrome: treatment with catheter mediated thrombolysis and endovascular stent placement. Radiology 1998;206:187—93. [3] Bashist B, Parisi A, Frager DH, Suster B. Abdominal CT findings when the superior vena cava, brachiocephalic vein, or subclavian vein is obstructed. AJR Am J Roentgenol 1996;167(6):1457—63. [4] Kapur S, Paik E, Rezaei A, Vu DN. Where there is blood, there is a way: unusual collateral vessels in superior and inferior vena cava obstruction. Radiographics 2010;30(1): 67—78. [5] Dickson AM. The focal hepatic hot spot sign. Radiology 2005;237:647—8. [6] Maldjian PD, Obolevich AT, Cho KC. Focal enhancement of the liver on CT: a sign of SVC obstruction. J Comput Assist Tomogr 1995;19:316—8. [7] Lanciego C, Pangua C, Chacon JI, Velasco J, Boy RC, et al. Endovascular stenting as the first step in the overall management of malignant Superior Vena Cava Syndrome. AJR Am J Roentgenol 2009;193:549—58.
[1] Holmquist DL, Burdine JA. Caval-portal shunting as a cause of a focal increase in madiocolloid uptake in normal livers. J Nucl Med 1973;14:348—51.
Please cite this article in press as: Pahwa S, et al. Hepatic hot spot sign: Beacon of SVC obstruction. Clin Res Hepatol Gastroenterol (2014), http://dx.doi.org/10.1016/j.clinre.2014.03.008
ARTICLE IN PRESS
CLINRE-574; No. of Pages 2
Clinics and Research in Hepatology and Gastroenterology (2014) xxx, xxx—xxx
Available online at
ScienceDirect www.sciencedirect.com
IMAGE OF THE MONTH
Hepatic hot spot sign: Beacon of SVC obstruction Shivani Pahwa a, Chandan J. Das a,∗, Sanjay Sharma a, Arun Kumar Gupta a, Aparajit Ballav Dey b a b
Department of Radiodiagnosis, All India Institute of Medical Sciences, 110029 New Delhi, India Department of Geriatric Medicine, All India Institute of Medical Sciences, 110029 New Delhi, India
Case summary A 65-year-old male patient presented with complaints of vague abdominal pain and malaise for six months. Contrastenhanced computed tomography (CECT) of the abdomen revealed a sharply demarcated, intensely enhancing area in the quadrate lobe of liver (Fig. 1A, arrow) and tortuous thoracic and abdominal wall collaterals (Fig. 1B, arrow). This constellation of findings is highly specific for superior vena cava (SVC) obstruction. The enhancing area in liver (‘‘hepatic hot spot’’) may look like a mass, but arises due to development of porto-systemic shunting in SVC obstruction. CECT chest was performed to determine the cause of obstruction. It revealed a mass in upper lobe of right lung, with the tumor thrombus completely occluding the SVC (Fig. 1C, arrow) — biopsy revealed squamous cell carcinoma. The patient was managed by placing an endovascular bare stent bypassing the malignant obstruction.
Discussion Focally increased uptake of radionuclide in liver on 99m Tc sulfur colloid scans due to opening up of collateral
∗ Corresponding author. Tel.: +91 90 13217076; fax: +91 11 26588663. E-mail address: [email protected] (C.J. Das).
pathways in superior vena cava obstruction was first described by Holmquist and Burdine [1]. Thoracic malignancies (bronchogenic carcinoma, lymphoma, metastases) are responsible for up to 85% cases of SVC obstruction [4]. Benign causes contribute to about 15% of cases and are mostly iatrogenic, due to invasive vascular access devices for chemotherapy, hyperalimentation, infusion of fluids, or due to invasive monitoring devices like pacemaker electrodes, and catheters for central venous pressure monitoring [2]. Less commonly, conditions like mediastinal fibrosis, infections, sarcoidosis, aortic aneurysms, and radiation fibrosis can cause occlusion of the SVC. Complete SVC obstruction can open up four major collateral pathways depending upon the level of obstruction: • • • •
the azygos-hemiazygos pathway; the internal and external mammary pathway; the lateral thoracic pathway; and the vertebral pathway [3].
Apart from these major collaterals, unusual cavoportal, intrahepatic, and systemic-to-pulmonary venous collaterals are seen infrequently [4]. An intensely enhancing area — the ‘‘hot spot’’ — is seen in the quadrate lobe (segment IV) of liver due to the development of cavoportal collaterals [4—6]. The superior and inferior epigastric veins communicate with the internal mammary vein. These veins drain into a recanalised paraumbilical vein, which in turn empties into the left portal vein. Internal mammary vein may also
http://dx.doi.org/10.1016/j.clinre.2014.03.008 2210-7401/© 2014 Elsevier Masson SAS. All rights reserved.
Please cite this article in press as: Pahwa S, et al. Hepatic hot spot sign: Beacon of SVC obstruction. Clin Res Hepatol Gastroenterol (2014), http://dx.doi.org/10.1016/j.clinre.2014.03.008
+Model CLINRE-574; No. of Pages 2
ARTICLE IN PRESS
2
S. Pahwa et al.
Figure 1 A. Axial contrast-enhanced computed tomography (CECT) image of the abdomen depicts a sharply demarcated, intensely enhancing area — ‘‘the hot spot’’ — in segment IV of liver (arrow). B. Shaded surface display (SSD) image illustrates the cavoportal collaterals in the thoracic and abdominal wall. C. Coronal CECT image demonstrates a mass in the upper lobe of right lung, with tumor thrombus completely occluding the superior vena cava (SVC) (arrow) — biopsy revealed squamous cell carcinoma.
drain into the inferior phrenic vein, which communicates with the portal vein tributaries through the hepatic capsular veins. The ‘‘hot spot’’ sign is not seen frequently because development of azygos-hemiazygos circulation is much more common. The hepatic ‘‘hot spot’’ on a contrast-enhanced CT should not be confused with a liver mass and its presence should prompt the search for underlying SVC obstruction. SVC obstruction can be managed through endovascular route with placement of a stent bypassing the obstruction. This is the first line, palliative management option that rapidly improves symptoms [6,7].
Disclosure of interest The authors declare that they have no conflicts of interest concerning this article.
References
[2] Kee ST, Kinoshita L, Razavi MK, Nyman OU, Semba CP, Dake MD. Superior Vena Cava Syndrome: treatment with catheter mediated thrombolysis and endovascular stent placement. Radiology 1998;206:187—93. [3] Bashist B, Parisi A, Frager DH, Suster B. Abdominal CT findings when the superior vena cava, brachiocephalic vein, or subclavian vein is obstructed. AJR Am J Roentgenol 1996;167(6):1457—63. [4] Kapur S, Paik E, Rezaei A, Vu DN. Where there is blood, there is a way: unusual collateral vessels in superior and inferior vena cava obstruction. Radiographics 2010;30(1): 67—78. [5] Dickson AM. The focal hepatic hot spot sign. Radiology 2005;237:647—8. [6] Maldjian PD, Obolevich AT, Cho KC. Focal enhancement of the liver on CT: a sign of SVC obstruction. J Comput Assist Tomogr 1995;19:316—8. [7] Lanciego C, Pangua C, Chacon JI, Velasco J, Boy RC, et al. Endovascular stenting as the first step in the overall management of malignant Superior Vena Cava Syndrome. AJR Am J Roentgenol 2009;193:549—58.
[1] Holmquist DL, Burdine JA. Caval-portal shunting as a cause of a focal increase in madiocolloid uptake in normal livers. J Nucl Med 1973;14:348—51.
Please cite this article in press as: Pahwa S, et al. Hepatic hot spot sign: Beacon of SVC obstruction. Clin Res Hepatol Gastroenterol (2014), http://dx.doi.org/10.1016/j.clinre.2014.03.008
