Hepatic Cysts: Reappraisal of the Classification, Terminology, Differential Diagnosis, and Clinicopathologic Characteristics in 258 Cases.

The literature on liver cysts is highly conflicting, mostly owing to definitional variations. Two hundred and fifty-eight ≥1 cm cysts evaluated pathologically using updated criteria were classifiable as: I. Ductal plate malformation related (63%); that is, cystic bile duct hamartoma or not otherwise specified-type benign biliary cyst (35 with polycystic liver disease). These were female predominant (F/M=2.4), large (10 cm), often multifocal with degenerative/inflammatory changes and frequently misclassified as "hepatobiliary cystadenoma." II. Neoplastic (13%); 27 (10.5%) had ovarian-type stroma (OTS) and qualified as mucinous cystic neoplasm (MCN) per World Health Organization (WHO). These were female, solitary, mean age 52, mean size 11 cm, and 2 were associated with carcinoma (1 in situ and 1 microinvasive). There were 3 intraductal papillary neoplasms, 1 intraductal oncocytic papillary neoplasm, 1 cystic cholangiocarcinoma, and 2 cystic metastasis. III. Infectious/inflammatory (12%). These included 23 hydatid cysts (including 2 Echinococcus alveolaris both misdiagnosed preoperatively as cancer), nonspecific inflammatory cysts (abscesses, inflammatory cysts: 3.4%). IV. Congenital (7%). Mostly small (<3 cm); choledochal cyst (5%), foregut cyst (2%). V. Miscellaneous (4%). In conclusion, hepatic cysts occur predominantly in women (3/1), are mostly (90%) non-neoplastic, and seldom (<2%) malignant. Cystic bile duct hamartomas and their relative not otherwise specified-type benign biliary cysts are frequently multifocal and often misdiagnosed as "cystadenoma/carcinoma." Defined by OTS, MCNs (the true "hepatobiliary cystadenoma/carcinoma") are solitary, constitute only 10.5% of hepatic cysts, and have a significantly different profile than the impression in the literature in that essentially all are perimenopausal females, and rarely associated with carcinoma (7%). Since MCNs can only be diagnosed by demonstration of OTS through complete microscopic examination, it is advisable to avoid the term "cystadenoma/cystadenocarcinoma" solely based on radiologic examination, and the following simplified terminology would be preferable in preoperative evaluation to avoid conflicts with the final pathologic diagnosis: (1) noncomplex (favor benign), (2) complex (in 3 subsets, as favor benign, cannot rule out malignancy, or favor malignancy), (3) malignant features.

Non-invasive diagnostic criteria of hepatocellular carcinoma: Comparison of diagnostic accuracy of updated LI-RADS with clinical practice guidelines of OPTN-UNOS, AASLD, NCCN, EASL-EORTC, and KLSCG-NCC.

PURPOSE: To retrospectively compare the diagnostic performance of different noninvasive diagnostic criteria of HCC including LI-RADS, OPTN-UNOS, AASLD, NCCN, EASL-EORTC, KLCSG-NCC. MATERIALS AND METHODS: We reviewed the medical records of 3,491 pathologically examined liver lesions from January-2011 to January-2015 in our institution. 195 lesions in 133 patients (M:F = 100:33) with chronic hepatitis B/C and/or cirrhosis for any etiology were finally included in our study, with 98 lesions ≥ 2 cm, 72 lesions between 1-2 cm, and 25 lesions < 1 cm. The main comparison was made with the largest nodules of each patient (n = 133). The lesions were retrospectively evaluated for the diagnosis of HCC on DCE-CT or MR using different noninvasive diagnostic criteria including LI-RADS, OPTN-UNOS, AASLD, NCCN, EASL-EORTC, and KLCSG-NCC. With pathological evaluation serving as a gold-standard, sensitivity, specificity, PPV and NPV as well as accuracy of the diagnostic criteria were calculated. RESULTS: There was no statistically significant differences in diagnostic accuracy among noninvasive diagnostic criteria. For 133 lesions of the largest lesion per patient, the overall accuracy was highest with LI-RADS criteria (89.3%) and the overall sensitivity was highest with LI-RADS, AASLD, NCCN criteria (all 89.5%). For 1-2 cm lesions, sensitivity decreased for all criteria in the following order: EASL-EORTC (59.1%), KLCSG-NCC (58.3%), LI-RADS, AASLD, NCCN (all 56.5%), and OPTN-UNOS (22.7%) criteria. OPTN-UNOS had the highest specificity in cirrhotic livers, 91.7%. CONCLUSIONS: The current noninvasive diagnostic criteria of HCC have no statistically significant difference in diagnostic accuracy. Overall, LI-RADS had the highest sensitivity and accuracy among the guidelines. OPTN had the highest specificity for cirrhotic livers.

Comparative analysis of hypervascular microcystic serous cystadenoma with MRI and immunohistochemistry.

PURPOSE: Cystic tumors of the pancreas are increasingly common lesions. Unlike mucinous cystic tumors, serous cystadenomas are benign lesions and do not pose a risk of cancer. Often seen in women in the 6th and 8th decades, they are rarely seen in younger women or in male patients. Serous cystadenomas do not require surgical treatment unless they produce symptoms due to compression. Sometimes they may be misdiagnosed as cystic neuroendocrine tumors and resected because of the contrast enhancement on contrast enhanced cross-sectional studies. The purpose of this article is a translational analysis of why a cystic tumor enhances. MATERIAL AND METHODS: The preoperative T2 HASTE, fat-suppressed T2 Turbo Spin Echo sequences, magnetic resonance cholangiopancreatography, diffusion weighted images, ex-vivo high-resolution T2 HASTE images of the post-operative pathologic specimen and immunohistochemical analysis with vascular marker CD31 were compared in a 58-yearold male patient with a pancreatic corpus microcystic serous cystadenoma. RESULTS: The nodular lesion is observed as fluid signal in T2 weighted sequences and enhancing in postcontrast series. Exvivo high-resolution MRI has also revealed cysts with millimetric different sizes and septations within the lesion. Evaluation with the CD31 vascular marker showed that fibrous septa between the cysts were dense vascular and stained. CONCLUSION: We show here that microcystic serous cystadenomas have intense vascularity of their septations that enhance in cross-sectional studies, especially when the cyst diameter is smaller. KEY WORDS: CD31, Microcystic, MRI, Serous cystadenoma.