1. Segment 2
   
2. Segment 3
   
3. Segment 4
   
4. Segment 5
   
5. Segment 8

The liver is morphologically divided into the right and left lobe by the line divided between gallbladder and inferior vena cava. Functionally, however, the liver is divided into 8 Couinaud segments based on the distribution of portal pedicles (hepatic artery, biliary, and portal vein) and hepatic veins. The left lobe of the liver is split into anterior (segments III, laterally and segment IV, medially) and posterior (segment II) sector by the left scissura which runs behind the ligament of teres and it contains left hepatic vein. The portal vein divides into main right and left branches at the hilum, and the left branch runs transversely at the base of segment IV and into the umbilical fissure, where it gives off branches to segments II & III and feedback branches to segment IV. The left portal vein also gives off posterior branches of the left side of caudate lobe (segment I). Therefore, the lesion appears to be in segment IV.

Answer: C

COUINAUDS SEGMENTS OF THE LIVER

Sabiston Chapter 53: The Liver; Anatomy and Physiology. In: CM Townsend, RD Beauchamp, BM Evers and KL Mattox Textbook of Surgery: The Biologic Basis of Modern Surgical Practice, April 2016, Elsevier, 20th edition.

1. Exploratory laparotomy
   
2. Give 2 L of crystalloid
   
3. Admit to regular ward for observation
   
4. Diagnostic laparoscopy
   
5. Angioembolization

This patient suffers a grade V blunt liver injury. Since he is a responder to 2 units of blood transfusion, he is a candidate for a nonoperative management which has 80–100% success rate. CT scan, however, demonstrates a contrast blush (red arrow) which makes him a candidate for angiogram and angioembolization. It also shows hemoperitoneum (black arrow) and liver injury (blue arrow). Angiographic embolization (AE) can be an adjunct to a nonoperative management and helps improve the success rate. Giving additional 2 L of crystalloid in this hemodynamically stable patient is not indicated and would hemodilute the patient (answer B). Admitting the patient to the ward for observation would be very risky as the patient may quickly become unstable and the blush indicates ongoing bleeding during the CT scan (answer C). Diagnostic laparoscopy is not needed as CT is an excellent method of diagnosis and diagnostic laparoscopy would not be therapeutic in terms of hemorrhage control (answer D). Taking the patient to operating room for either diagnostic laparoscopy or exploratory laparotomy is not yet indicated (answer D).

Advance one grade for multiple injuries up to grade III AAST liver injury scale (1994 revision).

Answer: E

Stassen NA, Bhullar I, Cheng JD, et al. Non‐operative management of blunt hepatic injury: an eastern association for the surgery of trauma practice management guideline. J Trauma & ACS 2012; 73: S288–S293.

Polanco PM, Brown JB, Puyana JC, et al. The swinging pendulum: a national perspective of nonoperative management in severe blunt liver injury. J Trauma & ACS 2013; 75: 590–595.

1. The majority (>90%) of patients with simple cysts are asymptomatic and do not need any intervention.
   
2. Atypical wall characteristics (asymmetric, thickening, nodular, lobular) and non‐homogeneous fluid are all benign changes and is not suspicious for malignancy.
   
3. Magnetic Resonance Imaging (MRI) is more accurate than ultrasound or computerized tomography (CT) scan in terms of characterizing the wall and the fluid content.
   
4. Sclerosing therapy is not appropriate for cyst that is easily accessible by surgery and has a high recurrence rate.
   
5. Laparoscopic fenestration (unroofing) while simple is dangerous and has high recurrence rate.

A simple liver cyst is the most common liver parenchymal imaging abnormality. The vast majority (>90%) of simple liver cysts are asymptomatic and do not need intervention. Increasing in size (stretching of the Gleason capsule), sudden hemorrhage, and/or communication with biliary system may cause patient to present with abdominal symptoms, early satiety, etc. Ultrasound and CT scan have classic characteristics of smooth wall without radiographic features of thickening, nodularity, or asymmetry; and the simple cyst contains homogenous fluid appearance. MRI has the advantage over the US/CT in its ability to characterize the fluid as well as identifying subtle mural nodules/projections that make one suspicious of something different than simple cyst. Interventional radiographic‐guidance needle aspiration and sclerosing is very effective (>90%) in the management of simple liver cyst but is limited by the size and the volume, but it has the advantage over surgery where cyst is not easily accessible. Laparoscopic fenestration (unroofing) also has > 90% success rate and more applicable to a very large size simple cyst that is easily accessible. Surgery is also appropriate if cyst communicates with biliary system which requires surgical closure.

Answer: C

Cameron JL, Cameron AL. (2017) Current Surgical Therapy, 13th Edition. In: John L. Cameron and Andrew M Cameron Cystic Disease of the Liver . Philadelphia, PA: Elsevier, p. 353–355.

Alshaikhli A, Al‐Hillan A. (2021) Liver Cystic Disease. In: StatPearls [Internet] . Treasure Island (FL): StatPearls Publishing Jan–. PMID: 33620816.

Mavilia MG, Pakala T, Molina M, Wu GY. Differentiating cystic liver lesions: a review of imaging modalities, diagnosis and management. J Clin Transl Hepatol . 2018; 6(2): 208–216. doi: 10.14218/JCTH.2017.00069. Epub 2018 Jan 5. PMID: 29951366; PMCID: PMC6018306.

Moorthy K, Mihssin N, Houghton PW. The management of simple hepatic cysts: sclerotherapy or laparoscopic fenestration. Ann R Coll Surg Engl . 2001; 83(6):409–14. PMID: 11777137; PMCID: PMC2503687.

1. Hepatic adenoma is benign and never needs resection.
   
2. Hepatic adenoma is commonly seen in the elderly.
   
3. Hepatic adenoma is the most common benign lesion of the liver.
   
4. Focal nodular hyperplasia (FNH) is a benign liver tumor that seldom appears similar to hepatic adenoma.
   
5. This patient needs resection due to her pain, size and possible degeneration into hepatocellular carcinoma.

Distinguishing hepatic tumors as benign or malignant is important in liver management. History and radiographic CT findings will help guide the diagnosis and management. Hepatic adenoma is a benign tumor that is seen in women of childbearing age and who are taking oral contraceptives. They often present with abdominal pain because of their size. They can require resection because of symptoms, and they can degenerate into hepatocellular carcinoma. Men and the beta‐catenin history pathological hepatic adenoma subtype are risk factors for malignant transformation. In comparison, lesion size and number, exophytic nature, and recent hormonal use in women are associated with bleeding. However, they are not the most common benign hepatic tumor as hemangiomas are the most comment benign hepatic tumor. Hemangioma has the CT characteristic of early enhancement of periphery. Focal nodular hyperplasia (FNH) is another benign hepatic tumor that can be difficult to distinguish from hepatic adenoma but it has a CT characteristic of central scarring.

Answer: C

Cameron JL, Cameron AL. (2017) Current Surgical Therapy, 13th Edition. In: John L. Cameron and Andrew M Cameron Management of Benign Liver Tumors . Philadelphia, PA: Elsevier, p. 371–372.

Silva JP, Klooster B, Tsai S, Christians KK, Clarke CN, Mogal H, Clark GT. Elective regional therapy treatment for hepatic adenoma. Ann Surg Oncol . 2019; 26(1): 125–130. doi: 10.1245/s10434‐018‐6802‐1. Epub 2018 Oct 23. PMID: 30353390.

Rodrigues BT, Mei SLCY, Fox A, Lubel JS, Nicoll AJ. A systematic review on the complications and management of hepatic adenomas: a call for a new approach. Eur J Gastroenterol Hepatol . 2020; 32(8): 923–930. doi: 10.1097/MEG.0000000000001766. PMID: 32433418.

1. BCA is usually a multi‐focal, non‐septate lesion
   
2. BCA has no potential for malignant transformation
   
3. BCA has characteristics similar to biliary intraductal papillary mucinous neoplasm (IPMN)
   
4. BCA predominately affects men
   
5. Surgical resection is a recommended treatment

Biliary cystadenoma (BCA) is a cystic neoplasm of the biliary ductular system that is thought to arise from ectopic clusters of embryonic bile ducts. BCA is typically a solitary multi‐septate lesion, often occupies left lobe, and is more common among woman with a median age of diagnosis of 45. Although BCA is biliary in nature, it lacks the papillary pathologic projection and superficial spreading growth as seen in biliary intraductal papillary mucinous neoplasm (IPMN) which is considered a malignant form. BCA is a benign neoplasm, but it has the potential for malignant transformation (20%) to biliary cystadenocarcinoma and hence, surgical resection is currently recommended. Due to the difficulty in accurately diagnosing these biliary cystic lesions and the availability of different surgical approaches, patients with suspected BCA or BCAC should be treated in a center specializing in liver surgery with state‐of‐the‐art imaging and all surgical techniques available to manage this rare disease.

Answer: E

Cameron JL, Cameron AL. (2017) Current Surgical Therapy, 13th Edition. In: John L. Cameron and Andrew M Cameron Management of Benign Liver Tumors . Philadelphia, PA: Elsevier, p. 371–372.

Klompenhouwer AJ, Ten Cate DWG, Willemssen FEJA, Bramer WM, Doukas M, de Man RA, Ijzermans JNM. The impact of imaging on the surgical management of biliary cystadenomas and cystadenocarcinomas; a systematic review. HPB (Oxford) . 2019; 21(10): 1257–1267. doi: 10.1016/j.hpb.2019.04.004. Epub 2019 May 10. PMID: 31085104.

1. A 3 cm lesion with bright homogeneous enhancement in the arterial phase with a central scar.
   
2. A 3 cm lesion with a heterogeneous appearance and arterial‐phase enhancement with a smooth surface.
   
3. A 3 cm lesion with centripetal enhancement on liver protocol CT.
   
4. A 3 cm asymmetric cystic lesion with no internal septation.
   
5. A 3 cm lesion with arterial enhancement and washout in the portal phase of CT.

Hepatocellular carcinoma (HCC) demonstrates CT arterial enhancement and a washout in the portal phase; hence, a surgical resection is indicated. A homogeneous enhancement in the arterial phase with central scarring is a classic presentation of focal nodular hyperplasia (FNH) which is a benign liver lesion and does not require surgical resection. A heterogenous appearance and arterial‐phase enhancement with a smooth surface suggests hepatic adenoma, again a benign liver lesion which does not require resection unless patient is symptomatic. A liver lesion with centripetal enhancement is a classic presentation of hemangioma, a cystic lesion with no internal septation suggests a simple cyst; both do not require surgical resection.

Answer: E

Cameron JL, Cameron AL. (2017) Current Surgical Therapy, 13th Edition. In: John L. Cameron and Andrew M Cameron Management of Benign Liver Tumors . Philadelphia, PA: Elsevier, p. 371–372.

Sabiston Chapter 53. The Liver. In: CM Townsend, RD Beauchamp, BM Evers and KL Mattox Textbook of Surgery: The Biologic Basis of Modern Surgical Practice, April 2016, Elsevier, 20th edition.

Gupta P, Bansal A, Das GC, Kumar MP, Chaluvashetty SB, Bhujade H, Gulati A, Kalra N. Diagnostic accuracy of liver imaging reporting and data system locoregional treatment response criteria: a systematic review and meta‐analysis. Eur Radiol . 2021 Mar 30. doi: https://doi.org/10.1007/s00330‐021‐07837‐6. Epub ahead of print. PMID: 33786656.

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