1. C.P.C. RUQ Cystic Mass and FeverBy
William E. Stevens M.D.

2. CPC Case Highlights Young, Latin-American, Male, Homosexual
2 weeks fever, chills, night-sweats
1 week RUQ pain
5-10 pound weight loss
Exam: temp 102.5; RUQ tenderness
Labs: normal WBC 5.7, mildly abnormal LFT’s (hepatitis risk factors); elevated total protein to albumin ratio; elevated CRP and ESR
CT scan: 8.5 cm cystic / solid mass in RUQ, heterogeneous, non-enhancing walls, IVC thrombosis, ?pushing or invading into liver

3. RUQ Cystic Mass and Fever Differential Considerations
Primary infection
Bacterial abscess
Amebic abscess
Echinococcosis
Malignancy
Liver
Adrenal
Renal
Pancreatic
Lymphoma, other
Benign Mass with secondary infection
Hepatic cyst with infection or focal cholangitis
Pancreatic pseudocyst with infection
Choledochal cyst
Renal, adrenal, mesenteric and duplication cysts
Multiple problems
Chronic viral hepatitis with a cystic mass
HIV infection with a cystic mass

4. Bacterial Abscess Pyogenic liver abscess Other abdominal abscesses
Symptoms: Fever 90%; pain 55%; weight loss 40%; jaundice 50%
Usually multiple 50%; right lobe involved 60%
Etiology: biliary 55%, cryptogenic 15%, other: appendicitis, diverticulitis, etc.
Other abdominal abscesses
Diverticular abscess
Perinephric abscess
Cholecystitis with abscess
Perforated ulcer with abscess
Perforated appendix with abscess
Treatment
Drainage, antibiotics, surgery

5. Amebic Abscess Entamoeba histolytica Pathophysiology
Fecal-oral transmission
5-10% in U.S. are asymptomatic cyst passers
Pathophysiology
Ingested cyst is resistant to gastric acid
Ameba becomes active in small intestine and passes into colon
Ameba invade colonic mucosa causing acute and chronic colitis
Ameba invade into mesenteric veins thus reaching the liver
Cystic necrosis of hepatocytes

6. Entamoeba histolytica

7. Amebic Abscess Clinical Presentation
More common in young, male, Latin-American, HIV+
60% have history of travel to endemic country
Duration of illness is usually < 2 weeks
20% have history of dysentery, 10% have dysentery
90% have RUQ pain or epigastric, chest or right shoulder pain
75% have fever
Right hepatic lobe involved in 80-95%
LFT’s mildly, nonspecifically elevated; < 10% jaundice
Leukocytosis and anemia are common

8. Amebic Abscess Diagnosis
Ultrasound and CT
Usually solitary, round, peripheral, right lobe
Through transmission, hypoechogenicity
Wall usually enhances with IV contrast
Occasionally will have nodular border or internal septations
Amebic Serology
ELISA has > 90% sensitivity
Can’t differentiate past from current infection
Liver Aspiration
Not usually necessary
Pus is reddish brown “anchovy paste”, usually sterile
Aspirate if diagnosis is uncertain, large abscess, “impending rupture”, left lobe involvement, non-response to treatment

9. Amebic Abscess Complications Treatment Pleuropulmonary rupture
Hepatic rupture, amebic peritonitis
Usually sudden severe abdominal pain
Occasionally slow leak with walled off abscess
Rupture into pericardium, pericarditis
Hemobilia
Rupture into bowel
Treatment
Aspiration if needed
Flagyl 750 mg TID for 10 days
Iodoquinol 650 mg TID for 20 days

10. Echinococcosis Echinococcus granulosa and multilocularis
Small 3-6 mm tape worms
Definitive host: Dog, others
Ingests infected viscera
Passes eggs into stool
Intermediate host: Human, sheep, cattle, others
Ingests food contaminated with egg laden feces
Egg is digested in small bowel releasing embryo
Embryo invades mucosa entering mesenteric veins
Embryo become trapped in liver (70%), lung (20%), spleen, kidney, bone, CNS, etc.
Endemic in areas where dogs are used to help raise livestock

11. Echinococcus granulosa

12. Echinococcus Life Cycle

13. Echinococcosis Symptoms occur years after acute infection Labs
Cyst produces mass effect enlarging ~1 cm/year
RUQ pain
CBD compression, obstructive jaundice
Portal vein compression, portal hypertension
Cyst may rupture; contents are highly antigenic
Anaphylactic shock
Free rupture into peritoneum
Rupture into biliary tract: obstruction, pancreatitis, cholangitis
Rupture into pleura, pericardium, colon, duodenum, kidney
Cysts may become secondarily infected
Labs
Mild leukocytosis, 40% have eosinophilia
ELISA IgG is 97% sensitive
Radiology
Cystic mass; walls occasionally calcified; rim often enhances with IV contrast
Daughter cysts

14. Echinococcosis CT Appearance

15. Echinococcosis Diagnosis Treatment Typical radiological appearance
MRI provides more data than CT
ELISA IgG is 97% sensitive
Aspiration is relatively contraindicated due to risk of cyst leakage and anaphylaxis
Treatment
Surgery: remove all cysts if possible
Avoid spillage of cyst contents
Large cysts may be injected with hypertonic saline and aspirated in OR before removal
10-30% recur
Albendazole 400 mg BID for 28 days
Non-surgical injection and aspiration only in unresectable cysts or patients who are non-operable

16. Neoplastic Hepatic Cysts
Any primary or metastatic cancer can appear cystic due to central necrosis or hemorrhage
Choriocarcinoma, ovarian carcinoma, sarcoma, islet cell tumors, lymphoma
Biliary cystadenoma / cystadenocarcinoma
Most common in women over age 40
Cystic, septated masses, irregular wall margins, more often in right lobe
Mucous secreting cuboidal epithelium with ovarian type stroma
Walls and septations are more vascular by pulse doppler
Cavernous hemangioma
Most common hepatic tumor; usually asymptomatic
Men = women, but estrogens enhance growth
Often appear cystic, occasionally pedunculated
Rarely will rupture, usually due to trauma
Teratoma
Mesenchymal hamartoma

17. Benign Noninfectious Hepatic Cysts
Solitary
Simple Cysts
3.6% population; F:M = 4:1
Almost always asymptomatic
Usually <5 cm, usually right lobe
Thin walls; more than one cyst may be present
Post-traumatic
Post-hepatic infarction
Rarely can cause pain, hemorrhage, become infected
Polycystic
Autosomal dominant adult polycystic kidney disease
Autosomal recessive polycystic kidney disease and Congenital hepatic fibrosis
Caroli’s Disease
Von Meyenburg complexes
Other congenital syndromes
Peliosis hepatis

18. Other RUQ Cystic Masses
Pancreatic Cysts
Simple pancreatic cysts
Pancreatic pseudocysts
Almost always have a history of pancreatitis or trauma
Complicates 10% cases of acute pancreatitis
More common in ETOH pancreatitis
Usually lack septae; may be loculated; may have calcium; cysts may travel to unexpected areas
Cyst fluid has a very high amylase
Pancreatic cystic neoplasm
80% are women; usually > 55 years old; usually involve body and tail pancreas
Mucinous cystic neoplasm (45%); intraductal papillary mucinous neoplasm (30%); serous cyst adenoma (15%)
EUS is best diagnostic test
Choledochal Cysts
Congenital cystic dilation of the biliiary tract
60% present before age 10
Recurrent RUQ pain, fever, abnormal LFT’s

19. More RUQ Cystic Masses Adrenal Cysts Renal Cysts Mesenteric Cysts
15% of adrenal cysts are malignant
Adrenal cortical carcinoma and adenoma
Pheochromocytoma
Cystic lymphangioma and neuroblastoma
85% are benign
Hemorrhagic adrenal pseudocyst
Hydatid cyst
Renal Cysts
Solitary cysts and Polycystic kidney disease
Renal cell carcinoma
male > female; usually age > 50; increased risk IVC thrombosis; 60% have hematuria
Mesenteric Cysts
Very rare; 3% are malignant
60% have localized pain, occasionally fever, chills
Duplication Cysts
Rare; congenital; attached to gut; lined by G.I. mucosa

20. HIV Related Liver Diseases
Hepatitis B and C
Increased incidence in HIV+ patients
When compared to HIV negative patients:
Higher viral load
Lower ALT
More severe histology
Less responsive to medical therapy
Mortality from liver disease much higher
Increased risk of Hepatoma and Lymphoma with chronic hepatitis
Peliosis hepatis
Fever, RUQ pain, hepatic cystic masses usually < 3cm in size
Blood filled cavities
Related to Bartonella infection; CD-4 count < 200
Amebic abscess
60% of patients without a travel history are immunosuppresed or HIV+
Many others: fungal abscess, Kaposi’s sarcoma, Lymphoma

21. RUQ Cystic Mass and Fever Diagnostic Studies
Recommend:
Send serologies for ameba and Echinococcus
Send serologies for HIV, Hepatitis B and C
Aspirate and Biopsy cystic mass if ameba and Echinococcus serologies are negative