2016 Comprehensive Update of the Banff Working Group on Liver Allograft Pathology: Introduction of Antibody-Mediated Rejection.

The Banff Working Group on Liver Allograft Pathology reviewed and discussed literature evidence regarding antibody-mediated liver allograft rejection at the 11th (Paris, France, June 5-10, 2011), 12th (Comandatuba, Brazil, August 19-23, 2013), and 13th (Vancouver, British Columbia, Canada, October 5-10, 2015) meetings of the Banff Conference on Allograft Pathology. Discussion continued online. The primary goal was to introduce guidelines and consensus criteria for the diagnosis of liver allograft antibody-mediated rejection and provide a comprehensive update of all Banff Schema recommendations. Included are new recommendations for complement component 4d tissue staining and interpretation, staging liver allograft fibrosis, and findings related to immunosuppression minimization. In an effort to create a single reference document, previous unchanged criteria are also included.

Impact of liver fibrosis on prognosis following liver resection for hepatitis B-associated hepatocellular carcinoma.

BACKGROUND: This study aims to evaluate the impact of liver fibrosis severity on prognosis following liver resection among HBV-HCC patients. METHODS: Data were extracted from a prospective database of 189 HBV-HCC patients treated at Mount Sinai between 1995 and 2008. Fibrosis staging of each surgical resection specimen using the modified Ishak method was performed by a single liver pathologist. RESULTS: A wide range of Ishak fibrosis stage was observed among this patient population, with 29% having established cirrhosis (Ishak stage 6). Ishak stage 6 was independently associated with poor overall and recurrence-free survival. In patients with Ishak stage 1-5, Ishak stage did not affect survival; rather, tumour size was associated with poor overall survival, and tumour size, histologic activity index and serum AFP>20 ng ml(-1) were associated with poor recurrence-free survival. In patients with Ishak stage 6, poorly differentiated histology and tumour size were associated with poor overall survival, and tumour size was associated with poor recurrence-free survival. CONCLUSION: HBV-HCC develops with varying degrees of underlying liver fibrosis; however, progressive liver fibrosis does not affect the outcomes following resection until cirrhosis is reached. Established cirrhosis, as defined histologically by Ishak stage 6, is an independent predictor of poor overall and recurrence-free survival among these patients.

Restoration of distorted colour microscopic images from transverse chromatic aberration of imperfect lenses.

An algorithm is presented for restoration of colour microscopic images with distortions from imperfect microscope lenses having transverse chromatic aberrations, resulting in a magnification that slightly varies with wavelengths or colours. The differential of each colour component image is computed as the difference between the component image and its slightly magnified version. The absolute values in the differential component images are generally higher at the edges where greater discontinuities occur. The two cross-correlation functions of the absolute differentials between red and green colours and between red and blue colours are then computed. The maximum in the two cross-correlation functions were sought, respectively, and the cross-correlation delays were then calculated. The two cross-correlation delays were used to determine dispersions and to realign the three colour components. Results of real microscopic images are provided. The restored image and the original are compared both visually and quantitatively in terms of the estimated entropies measured for the degree of concentrations using vector distributions.

Nevirapine-induced stevens johnson-syndrome and fulminant hepatic failure requiring liver transplantation.

We describe a case of nevirapine-induced Stevens-Johnson Syndrome (SJS) and fulminant hepatic failure (FHF) requiring liver transplantation. Five weeks prior to admission, a 57-year-old female with HIV infection had been switched to a nevirapine-based regimen of highly active antiretroviral therapy (HAART) with a CD4 cell count of 695/mm(3). Examination of the explanted native liver at initial transplantation revealed massive hepatic necrosis consistent with drug-induced liver injury. Primary graft nonfunction complicated the early postoperative course and liver retransplantation was required. On follow-up 2 years later, she remains in good health with an undetectable viral load on an efavirenz-based regimen of HAART. To our knowledge, this is the first report of successful liver transplantation following SJS and FHF.

Inverse association between hepatic stellate cell apoptosis and fibrosis in chronic hepatitis C virus infection.

Perisinusoidal hepatic stellate cells (HSC) are the principal fibrogenic cells in the liver. In animal models, HSC apoptosis is the predominant clearance mechanism of activated HSC, although data evaluating whether the same processes occur in humans are limited. We conducted a cross-sectional study to evaluate the association between HSC apoptosis and fibrosis stage in subjects with chronic hepatitis C virus (HCV) infection (n = 44) and HCV-negative controls with normal liver histology (n = 9). We used immunohistochemical techniques to identify activated (alpha-smooth muscle actin+), proliferative (Ki-67+) and apoptotic (terminal deoxynucleotidyl transferase [TdT]-mediated dUTP nick end-labelling+) HSC in liver biopsy specimens from all subjects. The same pathologist enumerated positive cells per high-power field (HPF, x 200) in 20 periportal/lobular areas. HSC apoptosis was decreased in HCV-positive subjects compared with controls (median 0.4, range 0.0-3.1 vs 1.1, 0.2-3.5 cells/HPF, P = 0.02). Among HCV-positive subjects, HSC apoptosis was decreased in those with moderate to advanced fibrosis (P = 0.04) compared with those with mild fibrosis. By multivariate analysis, HSC apoptosis decreased by an average of 0.14 cells/HPF (95% confidence interval 0.01-0.28 cells/HPF) per increase in fibrosis stage (P = 0.04). While the number of activated and proliferative HSC was significantly increased in HCV-infected subjects compared with that in uninfected controls, the numbers of these cells did not differ between HCV-infected subjects with mild vs moderate/advanced fibrosis. In conclusion, the number of apoptotic HSC was significantly decreased in HCV-infected subjects with advanced fibrosis. In chronic HCV infection, inhibition of HSC apoptosis may be one mechanism by which fibrosis progresses.

Hepatic inflammatory cytokine mRNA expression in hepatitis C virus-human immunodeficiency virus co-infection.

Although epidemiologic studies have documented that hepatitis C virus (HCV)/human immunodeficiency virus (HIV) co-infected patients have accelerated fibrogenesis, especially those with CD4+ cell counts <200 cells/mm(3), the pathogenic mechanisms are poorly understood. We investigated whether severe immunodeficiency in co-infection is associated with changes in intrahepatic inflammatory cytokine mRNA levels. We measured interferon (IFN)-gamma, tumour necrosis factor-alpha, transforming growth factor (TGF)-beta(1), interleukin (IL)-4, IL-10, IL-12p35 and IL-12p40 mRNA levels by real-time PCR performed on liver samples from HCV mono-infected (n = 19) and HCV/HIV co-infected (n = 24) patients. Co-infected patients had decreased intrahepatic mRNA levels of IFN-gamma (P = 0.09), IL-4 (P = 0.05) and IL-12p35 (P = 0.04) compared with mono-infected patients, while IL-10 was increased (P = 0.07). In co-infected patients, IFN-gamma mRNA levels increased linearly with increasing peripheral CD4+ cell counts by 1.23 times relative to the calibrator for every 100 CD4+ cells/mm(3) increase (P = 0.02). No other cytokines were significantly associated with CD4+ cell counts. In conclusion, HIV-induced lymphopenia may result in hepatic inflammatory cytokine suppression in HCV/HIV co-infection. Intrahepatic IFN-gamma levels are significantly reduced in patients with advanced immunodeficiency. Further studies are needed to assess whether decreased IFN-gamma secretion by HCV-specific CD4+ cells may account for accelerated fibrogenesis in these patients.

Image segmentation of liver fibrosis.

Quantitation of connective tissue versus parenchymal tissue compartments is important in assessment of fibrosis (scarring) and its progression in liver disease. This paper presents a two-step algorithm for quantifying fibrosis in liver biopsies stained with Sirius red. With this staining technique, collagen and cell nuclei appear similarly stained, whereas cytoplasm appears pale. The first step of the algorithm is to separate similarly stained areas occupied by collagen and hepatocyte nuclei. Since the total area of the combined collagen and cell nuclei is usually much smaller than the remaining liver parenchyma, a non-linear intensity mapping is applied to enhance the smaller cluster in order to match the larger one in both intensity and size. The second step is to differentiate the fibrotic areas usually having irregular shapes from hepatocyte nuclei that have relatively uniform size and have circular shape. The proposed algorithm has been applied to quantify the development of progressive fibrosis and its possible regression in liver biopsy specimens from patients with parenteral-induced liver injury undergoing intestinal transplantation.

Development of hepatic granulomas in patients receiving pegylated interferon therapy for recurrent hepatitis C virus post liver transplantation.

UNLABELLED: Infrequently, hepatitis C (HCV) appears to be the cause of hepatic granulomas. Interferon therapy for HCV has been increasingly associated with the development of sarcoidosis. AIMS: We sought to determine the incidence of hepatic granulomas in patients with recurrent HCV post liver transplantation (LT). METHODS: Between 1994 and 2005, 820 patients were transplanted for HCV at our institution. The pathology database was searched for patients having recurrent HCV and granulomas. At Mount Sinai Medical Center, protocol biopsies have been performed for the last 2 years in patients receiving pegylated interferon-alpha2b and ribavirin (PEG) for recurrent HCV. Review of slides from explanted livers, pre- and post-perfusion biopsies, and all allograft biopsies were evaluated. Lipogranulomas were excluded because of their frequent association with steatosis. RESULTS: A total of 10,225 liver biopsies were performed on HCV patients, and 25 (0.24%) showed non-caseating epithelioid granulomas. Hepatic granulomas were detected in 14 post-LT HCV patients; 9 patients received PEG. Typically, only 1 lobular granuloma was found. None of these patients had granulomas in the native liver or in any biopsy before interferon therapy; 6/9 patients had undetectable HCV-RNA levels, and 4 had sustained viral response. No other cause for granuloma formation was identified in the 6 patients. CONCLUSIONS: Hepatic granulomas are infrequently found in HCV liver biopsies and rarely found in post-LT biopsies with recurrent HCV. When present, they occur more commonly in patients receiving and virologically responding to PEG therapy. The presence of granulomas in patients with HCV being treated with PEG may not warrant an extensive etiologic work-up for granulomatous hepatitis unless otherwise clinically indicated.

Identification of ultrastructural changes in liver allografts of patients experiencing primary nonfunction.

BACKGROUND: Primary nonfunction (PNF) after liver transplantation is fatal without timely retransplantation. PNF has been associated with many risk factors, but the etiology remains unknown in most cases. Using electron microscopy, we examined the hepatic ultrastructure of donor allografts in patients experiencing PNF and compared the findings with a well-matched group of other donor allografts. MATERIALS AND METHODS: Archival paraffin-embedded pre- and post-reperfusion donor liver biopsies were examined by electron microscopy in 10 patients with PNF and in 10 controls, matched by donor age +/- 5 years, gender, cold ischemic time +/- 1 hour, and donor cause of death. Mitochondria, endoplasmic reticulum, sinusoidal endothelial cells, and the glycogen content of the cells were assessed. The donors' serum peak transaminases, bilirubin and sodium levels, as well as the recipient age and serum creatinine were compared. RESULTS: There were no significant differences in recipient age at the time of transplantation, peak recipient serum creatinine, donor peak serum transaminase, sodium or bilirubin levels. In all cases, the endoplasmic reticulum and sinusoidal endothelial cells were ultrastructurally normal. Hepatocytes had variable degrees of glycogen pooling. Hepatic steatosis and intramitochondrial inclusions cells were present in 5/10 PNF compared to 0/10 controls patients on preperfusion liver biopsy (P = .17). CONCLUSION: Liver allografts from patients suffering from PNF can have mitochondrial ultrastructural changes on preperfusion biopsies.

Recurring fibro-obliterative venopathy in liver allografts.

Recurrent diseases in liver allografts are not uncommon. These occur most frequently in those transplanted for viral hepatitis B and C. We report an unusual case of recurrent process in two consecutive liver allografts received by a 37-year-old woman, who previously had an unremarkable past medical history but developed a rapidly progressive cholestatic liver failure. Histopathologic examination of the native liver showed fibroocclusive lesions of both terminal hepatic venules and portal vein branches. The exuberant fibroobliterative process created dense fibrosis with whorled appearance, and broad fibrous septa connecting adjacent central areas, and sometimes bridging portal to central areas. Dense portal fibrosis resulted in compression atrophy and loss of bile ducts. The first allograft, which failed within 3 months, showed histopathologic findings similar to that of the native liver. A liver biopsy that was performed 20 months after the second liver transplant again showed similar histopathology. The histopathologic features and clinical presentation of this patient suggest an unusual form of recurring progressive fibroobliterative venopathy causing liver failure.

Absence of hepatitis G virus within liver tissue of patients undergoing liver transplantation for cryptogenic cirrhosis.

BACKGROUND: Epidemiological studies have detected up to a 9% incidence of hepatitis G (HGV)-RNA in patients with acute and chronic liver disease of unknown etiology. We sought to clarify the role of HGV as a causative agent in cryptogenic cirrhosis by analyzing archival liver tissue for HGV-RNA in patients undergoing orthotopic liver transplantation. METHODS: Using a computer database, we identified 54 patients who underwent orthotopic liver transplantation for cryptogenic cirrhosis. After using rigorous serologic and histopathologic screening guidelines, 20 patients were studied, 7 of whom had concurrent hepatocellular carcinoma (HCC). RNA was extracted from archival paraffin-embedded liver tissue; HGV sequences were amplified by nested reverse transcription-polymerase chain reaction using primers designed from the 5' noncoding region. RESULTS: HGV-RNA was absent from all 20 liver specimens, including those 7 with HCC. Beta-actin RNA, used as a positive control for cellular RNA, was isolated from all 20 liver specimens, including the 7 with HCC. CONCLUSIONS: Utilizing a highly sensitive reverse transcription-polymerase chain reaction assay for HGV-RNA, we were unable to detect HGV-RNA within the livers of patients with cryptogenic cirrhosis or in the HCC arising within them. This lends further evidence to HGV infection not being a cause of cryptogenic cirrhosis and not being associated with the development of HCC in cryptogenic cirrhosis.

Use of livers with microvesicular fat safely expands the donor pool.

BACKGROUND: The safety of transplanting livers with moderate to severe microvesicular steatosis is unknown. Livers that appear fatty are often abandoned at the donor hospital. We have recently used frozen-section biopsy to distinguish between microvesicular and macrovesicular steatosis. We present here our single-center experience with transplantation of 40 allografts with moderate or severe microvesicular steatosis. METHODS: We reviewed our data on 426 transplants and identified 40 cases in which the donor liver contained at least 30% microvesicular steatosis. Early graft function, patient and graft survival, and donor risk factors for steatosis were examined, and results in this cohort were compared with results in all other patients who received liver transplants at our center during the same time period. We also analyzed the reliability of donor frozen-section biopsies in quantitating microsteatosis. Persistence of steatosis was assessed on the basis of 1-year follow-up biopsies. RESULTS: The incidence of primary nonfunction and poor early graft function was 5% and 10%, respectively. One-year patient and graft survival rates were 80% and 72.5%, respectively. Donor obesity and traumatic death were commonly identified risk factors for microvesicular steatosis. Frozen-section biopsy was reliable for pretransplant decision-making about the use of potential grafts, and the steatosis had disappeared from the graft at 1 year in the majority of cases. CONCLUSIONS: Livers with even severe microvesicular steatosis can be reliably used for transplantation without the fear of high rates of primary nonfunction. There was a significant incidence of poor early graft function, but this did not affect outcome. Microsteatosis is usually associated with some underlying risk factor in the donor and is reversible, as demonstrated by follow-up biopsies after transplant.

Safe use of hepatic allografts from donors older than 70 years.

Between March 1991 and August 1995, 36 livers from donors >/=70 years old were transplanted. In donors, we recorded the following risk factors: alanine aminotransferase > 120 and rising, dopamine dose > 15 microg/kg/min, hypotension (systolic blood pressure <80) >1 hr, stay in the intensive care unit >5 days and body mass index >/=27. In 35 recipients, we recorded pretransplant United Network for Organ Sharing (UNOS) status, cold/warm ischemia time, intraoperative blood loss, and occurrence of poor early graft function or primary nonfunction. Mean recipient age was 55 years (range, 25-75 years). Four recipients were UNOS status 1, 19 were UNOS 2, and 12 were UNOS 3. Two livers were used as second grafts for primary graft nonfunction. Mean donor age was 73 years (range, 70-84 years). Intracranial bleeding was the cause of death in the majority of donors. The 36 donors had 40 risk factors; 10 donors had >1 risk factor. Mean cold and warm ischemia times were 9:08 +/- 2:57 hr and 51 +/- 9 min. Mean total operative time was 7.5 hr. Posttransplant mean peak alanine aminotransferase and aspartate aminotransferase levels were 937.3 +/- 703.1 IU/L and 923.3 +/- 708.5 IU/L, respectively. Mean prothrombin time on postoperative day 2 was 14.9 +/- 1.6 sec. Average total bilirubin on postoperative day 5 was 4.9 mg/dl. Median length of stay in the intensive care unit was 4 days. One recipient had poor early graft function; two recipients had primary nonfunction. Mean follow-up was 503 days (range, 110-1714 days). Three-month actual graft and patient survival rates were 85% and 91%, respectively. One-year actuarial graft and patient survival rates were also 85% and 91%, respectively. We conclude that older livers can be used safely. Advanced donor age should not be a contraindication to liver procurement.

Increased hepatic iron deposition resulting from treatment of chronic hepatitis C with ribavirin.

Increased levels of hepatic iron may impair the response of patients with chronic hepatitis C to treatment with interferon-alfa, but combination therapy with ribavirin has demonstrated efficacy in the treatment of hepatitis C. When used alone or with interferon-alfa, ribavirin may cause a dose-dependent reversible hemolytic anemia. We compared the extent and cellular localization of iron deposition in liver tissue from biopsy specimens obtained before and after 36 weeks of therapy with ribavirin or placebo for 59 patients with chronic hepatitis C. Paired slides were available for review from 26 ribavirin and 27 placebo recipients. Iron deposition was assessed using coded slides stained with Perls Prussian blue and was semi-quantitated in hepatocytes, Kupffer cells, and areas of fibrosis. The overall iron score fell by 0.96 in the placebo group and increased 1.69 in the ribavirin recipients. Iron was deposited mainly in hepatocytes; the hepatocyte iron score increased from 2.19 to 3.81 in the ribavirin group. The amount of iron staining in Kupffer cells declined in the placebo group and increased slightly in the ribavirin group. Iron changes in areas of fibrosis were minor and did not differ between groups. Increased total hepatic iron deposition occurred during a 9-month course of ribavirin. Ribavirin-associated hemolysis deposits iron preferentially in hepatocytes. This increased deposition of hepatic iron does not seem to affect the biochemical or histologic response to ribavirin therapy but may have implications for hepatocyte susceptibility to future injury.

Malignant schwannoma of the liver in a patient without neurofibromatosis: a case report and review of the literature.

Primary schwannomas of the liver are extremely rare. We report a case of malignant schwannoma of the liver occurring in a 49-year-old man, who did not have neurofibromatosis, and review the literature. The clinical and histologic findings of benign and malignant schwannomas of the liver are compared.

Epithelioid hemangioendothelioma of the liver mimicking Budd-Chiari syndrome.

A case of epithelioid hemangioendothelioma of the liver in a 34-year-old man with clinical and radiologic findings suggestive of Budd-Chiari syndrome is reported. Despite clinical and radiologic findings, percutaneous liver biopsy was suspicious for epithelioid hemangioendothelioma. The patient underwent liver transplantation 2 months later, and histologic examination confirmed this diagnosis. Unusual histopathologic features included extensive areas of capillary-thin vascular structures with open lumina, lack of significant cytologic atypia in the majority of neoplastic cells, and areas with Budd-Chiari-like features in the hepatic parenchyma surrounding the tumor. The neoplastic cells were focally immunopositive for endothelial markers, such as factor VIII-related antigen and CD34 antigen. The unusual clinical presentation may have been due to tumor invasion and fibrous obliteration of terminal hepatic venules and sublobular veins. Epithelioid hemangioendothelioma should be considered when evaluating patients with clinical features of Budd-Chiari syndrome or veno-occlusive disease.

Value of GCDFP-15 (BRST-2) as a specific immunocytochemical marker for breast carcinoma in cytologic specimens.

OBJECTIVE: The diagnosis of metastatic mammary carcinoma by morphologic criteria alone can be difficult, depending on the site of metastasis and state of cell differentiation. Numerous histopathologic studies have shown GCDFP-15 (BRST-2) to be a specific marker for breast cancer in surgical specimens. To date, no studies have been done to evaluate its utility in cytologic preparations. STUDY DESIGN: To evaluate the usefulness of GCDFP-15 as a marker in the cytologic diagnosis of breast carcinoma, we studied 23 cases of mammary carcinoma and compared them with 20 cases of tumors of nonmammary origin (lung, ovary, liver, colon, stomach and bladder). "Bench top" fine needle aspirates from unfixed surgical specimens of breast carcinoma, cytocentrifuge samples from body cavity fluids and cerebrospinal fluids with morphologically proven metastatic carcinoma were studied. RESULTS: Expression of BRST-2 was found in 56.5% of primary and recurrent or metastatic breast carcinomas. All the nonmammary carcinomas studied were negative. Staining was found to be strongly dependent on the means of cell fixation. Slides fixed in 10% formalin and Bouin's solution gave optimal results. Except in two cases, which showed focal immunostaining, all specimens fixed in alcohol were negative. CONCLUSION: Our results support the diagnostic value of GCDFP-15 in recognizing tumors of breast origin and suggest that in clinical situations in which metastatic breast carcinoma is suspected, a portion of the cytologic specimen should be fixed with an optimal fixative for BRST-2 detection.

Outcomes following liver resection and clinical pathologic characteristics of hepatocellular carcinoma occurring in patients with chronic hepatitis B and minimally fibrotic liver.

AIMS: The intent of this analysis is to assess clinico-pathologic and prognostic characteristics of HCC in patients with minimal liver fibrosis (Ishak stage 1-2) after primary surgical liver resection as compared to patients with moderate to severe fibrosis (Ishak stage 3-6) in order to improve screening and treatment of HCC. METHODS: Data were obtained from 200 patients with HBV-related HCC who underwent primary surgical liver resection at a single North American medical institution between 1988 and 2012. A dedicated liver pathologist performed fibrosis staging for each resection specimen using the modified Ishak method. Univariate and multivariate analyses of clinico-pathologic variables were performed to determine those associated with prognosis. RESULTS: Twenty-two percent of patients had minimal fibrosis defined as Ishak stage 1 or 2. Kaplan-Meier analysis of 5-year survival showed a non-significant trend toward better outcome among Ishak 1-2 patients compared to Ishak 3-6 (p = 0.09). Ishak 1-2 was associated with lower hazard of death compared to Ishak 3-6 (adjusted HR = 0.38, 95% CI = 0.15-0.99). Ishak 1-2 retained statistical significance after multivariate analysis for overall survival (p = 0.05), but not recurrence-free survival. CONCLUSIONS: A significant proportion of HBV-HCC cases arise in the minimally fibrotic liver. Patients with Ishak 1-2 fibrosis have better overall survival compared to those with Ishak 3-6, indicating that minimally fibrotic patients should be treated as a separate cohort. There is a need to better understand the mechanisms underlying hepatocarcinogenesis and to formulate unique diagnostic and therapeutic algorithms for minimally fibrotic HCC patients.

Liver transplantation is possible in some patients with liver metastasis of colon cancer.

Liver metastases from colorectal cancer are an absolute contraindication for liver transplantation. Aggressive therapy with liver resection and local chemotherapy in selected patients may be able to provide long-term cure. Given the risks of tumor recurrence, whether patients with post chemotherapy complications leading to liver failure should be offered transplantation is a challenging question in an era of limited organ availability. Herein we have presented 2 cases of liver transplantation performed in patients with colorectal cancer metastases treated with liver resection followed by hepatic artery infusion chemotherapy leading to development of sclerosing cholangitis and eventual liver failure. This report demonstrates that liver transplantation may be an option in selected patients with colorectal cancer liver metastases that have been well treated.

Natural history of small duct primary sclerosing cholangitis: a case series with review of the literature.

BACKGROUND AND AIMS: Information about the natural history of small duct primary sclerosing cholangitis (SDPSC) remains scant despite literature suggesting that it constitutes 6-16% of all cases of primary sclerosing cholangitis (PSC). We combined clinical data on SDPSC cases from two tertiary care institutions with liver transplantation programs with the aim of studying the natural history of SDPSC. METHODS: Medical records of 25 individuals with SDPSC were reviewed. Diagnosis of SDPSC was based on liver biopsy findings consistent with PSC, a normal cholangiogram, and elimination of known causes of secondary sclerosing cholangitis. Demographic information, symptoms, past medical history, laboratory values, and histologic data were evaluated. Our primary outcome measure was liver transplantation or death. Secondary outcome measures included evidence of end-stage liver disease, development of cholangiocarcinoma, and/or the development of classic PSC on a repeat cholangiogram. RESULTS: Data on 25 individuals (13 males, 12 females; mean age 40 ± 15 years) diagnosed with SDPSC were analyzed. Upon presentation, 11 patients had symptoms including abdominal pain, fatigue, and pruritus. Inflammatory bowel disease was present in 14 patients (56%) at diagnosis. On initial liver biopsy, 60% had early-stage disease (I or II) and none had cirrhosis. On follow-up (1-168 months, median 17 months), malignancy or progression to classic large duct PSC was not noted. Two (8%) patients had evidence of varices and one of the two also developed ascites; one of these patients underwent liver transplantation and the other one died due to sepsis. CONCLUSIONS: SDPSC, a mild disease at presentation typically runs a benign course and likely is not an early stage of classic PSC. Further studies with a control group of classic PSC and longer follow-up are needed to study the natural history of SDPSC.