Pancreatic cystic lesions: How endoscopic ultrasound morphology and endoscopic ultrasound fine needle aspiration help unlock the diagnostic puzzle

Table 1 Cystic lesions of the pancreas[19] (reprinted with permission of Dr. Parra-Herran CE)

Cystic lesions of the pancreas
Non-neoplastic cysts (30%-40%)
No lining
Inflammatory pseudocyst
Paraduodenal wall cyst
Infection-related cyst
True lining
Mucinous non-neoplastic cysts (mucoceles, retention cysts)
Cystic hamartoma
Enterogenous (congenital, duplication) cyst
Endometriotic cyst
Lymphoepithelial cyst
Squamoid cyst of pancreatic ducts
Others (unclassified)
Neoplastic cysts (60%-70%)
True lining
Mucinous lining (30%)
Intraductal papillary mucinous neoplasm (20%)
Mucinous cystic neoplasm (10%)
Serous lining (20%)
Serous cystadenoma (microcystic, oligocystic)
Von Hippel-Lindau-associated pancreatic cyst
Serous cystadenocarcinoma
Squamous lining (< 1%)
Epidermoid cyst within intrapancreatic accessory spleen
Dermoid cyst
Acinar cell lining (< 1%)
Acinar cell cystadenoma
Acinar cell cystadenocarcinoma
Endothelial lining (< 1%)
Lymphangioma
Solid tumors with cystic change (5%)
Solid pseudopapillary tumor
Ductal adenocarcinoma with cystic change
Neuroendocrine tumor with cystic change
Other invasive carcinomas with cystic change
No lining (< 1%)
Mesenchymal neoplasms with cystic change
Others (unclassified)

Table 2 Major features of four most common cystic lesions

Feature	SCN	MCN	IPMN	Pseudocyst
Prevalent age	Middle aged	Middle aged	Elderly	Variable
Sex	F > M	F1	M > F	M > F
Alcohol abuse	No	No	No	Yes
History of pancreatitis	No	No	Frequent	Yes1
Location	Evenly	Body-tail1	Head	Evenly
Malignant potential	Very rare	Moderate to high	Low to high	None

¹Mark the most useful epidemiological and clinical information (printed with permission of Dr. M Raimondi). SCN: Serous cystoadenoma neoplasm; MCN: Mucinous cystic neoplasm; IPMN: Intraductal papillary mucinous neoplasm.

Table 3 Endoscopic ultrasound morphology and cystic fluid analysis in pancreatic cystic lesions

	Serous cystoadenoma	Mucinous cystic neoplasm	BD-IPMN	Pseudocyst
Localization
Head	+++	+/-	+++	++
Body-tail	++	+++	++	++
Locularity
Unilocular	+	+	+	+++
Multilocular	+++	+++	+++	+
Internal structural features
Microcystic aspect	+++	-	+	-
Bunch of grape aspect	+	-	+++	-
Countors
Round	+	+++	+	+++
Lobulated	+++	+/-	+	+/-
Irregular	+/-	-	+++	-
Central scar	+	-	-	-
Visible cystic wall	-	++	+	+/++
Multifocality	-	-	++	+/-
Debris	-	-	-	++
Visible comunication with pancreatic duct	-	-	++	+
Calcification
Central	+	-	-	-
Periphery	-	+	-	+/-
Solid lesion	-	+	+	-
CEA
≥ 192 mg/mL	+/-	++	++	+/-
≥ 5 mg/mL	+	+++	+++	++
≤ 5 mg/mL	+++	+/-	+/-	+
Amylase
> 250 U/L	+	+/++	++/+++	+++
K-RAS mutation	-	++	++	-
Mucin	-	+	+	-
Cytology	Glycogen	Mucinous	Mucinous	Inflammatory

+++: Very frequent; ++: Moderately frequent; +: Infrequent; +/-: Possible but very infequent. BD-IPMN: Branch duct intraductal papillary mucinous neoplasm; CEA: Carcinoembryonic antigen.

Table 4 Accurancy of endoscopic ultrasound morphology in differentiating pancreatic cystic lesions (printed with permission of Dr M. Raimondi

Author	No. of patients	Study design	Accuracy (%)
Koito et al[57]	52	Retrospective	94
Cellier et al[64]	21	Retrospective	76
Pais et al[54]	51	Retrospective	86
Ahmad et al[60]	38	Retrospective	66
Sedlack et al[42]	34	Retrospective	82
Hernandez et al[58]	9	Retrospective	89
Frossard et al[59]	67	Retrospective	73
Brugge et al[61]	112	Prospective	51
Gerke et al[62]	66	Retrospective	67
Total	450		Median 72.5 (mean 77)