CYSTIC TUMORS OF THE PANCREAS

A.R.Fahim,M.D5,day,92

• Less than 10% of pancreatic neoplasms• Results of 24,000 abdominal CT and MRI during 8-

year period: pancreatic cysts in 1.2% of patients 60% cystic neoplasms• MCNs, serous cystadenomas, and IPMNs comprise

more than 80% • Masquerade as pancreatic pseudocysts• High cure rate following surgical treatment

DIFFERENTIAL DIAGNOSIS

Exclusion of a pancreatic pseudocyst:• lack an epithelial lining • history of acute or chronic pancreatitis, or abdominal trauma• lack of septae, loculations, solid components, or cyst wall calcifications on CT or MRI• communication between the cyst and the main

pancreatic duct• high levels of amylase

Does require surgical resection?• Slow growing, and favorable prognoses • Tumors with malignant potential include

MCNs, IPMNs, solid pseudopapillary tumors (SPTs), and cystic islet cell tumors

• Serous cystadenomas are almost universally benign

• Many of these cysts are very small (<2 cm)• Nonoperation• Operation: older than 70 years new symptoms cyst growth on serial imaging

DIAGNOSTIC IMAGING

• CT• MRI• ERCP• EUS• PET

Cyst Fluid Analysis in Cystic Lesions of the Pancreas

PARAMETER PSEUDOCYSTSEROUS CYSTADENOMA

MCN-BENIGN MCN-MALIGNANT IPMN

Viscosity Low Low High High High

Amylase High Low Low Low High

CEA Low Low High High High

CA 72-4 Low Low Intermediate High Intermediate to high

Cytologic findings Histiocytes

Cuboidal cells with glycogen-rich cytoplasm

Columnar mucinous epithelial cells with variable atypia

Adenocarcinoma cells

Columnar mucinous epithelial cells with variable atypia

MUCINOUS CYSTIC NEOPLASMS

• 10% to 45%• Thick-walled with occasional septations • Filled with thick mucous or hemorrhagic material • Benign, borderline, or malignant

(cystadenocarcinoma) • All these tumors should be treated as

premalignant lesions• Ovarian-type stroma

• Almost exclusively in women• Confined to the distal pancreas (body and tail

of the gland)• Never multifocal• Mean age is 50 years• Abdominal pain or a palpable mass• Incidental:25%

• MCN should be suspected when a CT or MRI of the abdomen shows a cyst within the body or tail of the pancreas in a middle-aged woman

• No communication between the pancreatic duct and the cyst itself

• EUS can identify septations and cyst wall nodules and allows cyst wall biopsy and cyst fluid aspiration

Cyst Fluid Analysis in Cystic Lesions of the Pancreas

PARAMETER PSEUDOCYSTSEROUS CYSTADENOMA

MCN-BENIGN MCN-MALIGNANT IPMN

Viscosity Low Low High High High

Amylase High Low Low Low High

CEA Low Low High High High

CA 72-4 Low Low Intermediate High Intermediate to high

Cytologic findings Histiocytes

Cuboidal cells with glycogen-rich cytoplasm

Columnar mucinous epithelial cells with variable atypia

Adenocarcinoma cells

Columnar mucinous epithelial cells with variable atypia

• Classification : benign adenomas (72%) borderline neoplasms (10.5%) carcinoma in situ (5.5%) invasive cancer (12%)• Malignant MCNs larger than benign counterparts (80 vs. 45 mm) more likely to harbor nodules within their walls

• Surgical resection is advocated for all of them• Distal pancreatectomy with or without

splenectomy • Laparoscopic approach is acceptable • Lymph nodes metastases are rare

• Given that MCNs are never multifocal, long-term surveillance is not required for patients with resected noninvasive tumors

SEROUS CYSTADENOMAS

• Microcystic adenoma• Second most common• Women (75%)• Mean age of 62 years• Most (50% to 70%) occur in the body or tail• Association with von Hippel-Lindau disease • Vague abdominal pain and discomfort,

palpable mass,incidental

• Numerous tiny cysts separated by delicate fibrous septa, giving them a honeycomb appearance

• The cysts are filled with clear watery fluid and are often arranged around a central stellate scar that may be calcified

• Spongy mass with a central “sunburst” calcification in CT:10%

Cyst Fluid Analysis in Cystic Lesions of the Pancreas

PARAMETER PSEUDOCYSTSEROUS CYSTADENOMA

MCN-BENIGN MCN-MALIGNANT IPMN

Viscosity Low Low High High High

Amylase High Low Low Low High

CEA Low Low High High High

CA 72-4 Low Low Intermediate High Intermediate to high

Cytologic findings Histiocytes

Cuboidal cells with glycogen-rich cytoplasm

Columnar mucinous epithelial cells with variable atypia

Adenocarcinoma cells

Columnar mucinous epithelial cells with variable atypia

• Benign • Surgical resection is the treatment of choice

for symptomatic lesions

• Observation if asymptomatic.• Observation carries the risk of continued

growth, which may lead to complications such as hemorrhage, obstructive jaundice, pancreatic insufficiency, or gastric outlet obstruction

• Tumors larger than 4 cm: resction

INTRADUCTAL PAPILLARY MUCINOUS NEOPLASMS

• IPMNs represent papillary neoplasms within the main pancreatic duct

• Benign (adenoma), borderline, or malignant(60%)

• Lymph node metastases( 33% to 51%)

• Men=women• Median age 65 years• Abdominal pain and weight loss• Recurrent pancreatitis: 20% • Acute pancreatitis:25% • Malignant neoplasms:older,jaundice or new-

onset diabetes

• CT or MRI: dilation of the pancreatic duct • ERCP:patulous ampulla of Vater with extruding

mucus(fish mouth) main duct dilation filling defects due to viscid mucus or tumor nodules communication between cystic areas and the main pancreatic duct

• Pancreaticoduodenectomy• Distal pancreatectomy • Total pancreatectomy

SOLID PSEUDOPAPILLARY TUMORS

• Less than 10% of the cystic tumors • Women:men (10 : 1 ratio)• Disease of young women in their 30s• Abdominal pain:50% • Large abdominal mass:35%• Incidental:15%• Body and tail:60%

• Carcinoma:20%• Complete loss of E-cadherin expression in the

cells or abnormal localization of E-cadherin to the cell nucleus:100%

• Very slow-growing• Complete resection