An Immunohistochemical Analysis of Osteopontin and S100 Calcium-binding Protein P is Useful for Subclassifying Large- and Small-duct Type Intrahepatic Cholangiocarcinomas.

Intrahepatic cholangiocarcinoma (iCCA) has been newly subclassified into two different subtypes: large-duct (LD) type and small-duct (SD) type. However, many cases are difficult to subclassify, and there is no consensus regarding subclassification criteria. LD type expresses the highly sensitive diagnostic marker S100 calcium-binding protein P (S100P), while SD type lacks sensitive markers. We identified osteopontin (OPN) as a highly sensitive marker for SD type. This study aimed to develop new subclassification criteria for LD-type and SD-type iCCA. We retrospectively investigated 74 patients with iCCA and subclassified them based on whole-section immunostaining of S100P and OPN. Of the 74 cases, 41 were subclassified as LD type, 32 as SD type, and one was indeterminate. Notably, all S100P-negative cases had OPN positivity. Seventy-three of the 74 cases (98.6%) were clearly and easily subclassified as LD or SD type using only these 2 markers. We also determined the value of immunohistochemistry in cases that were difficult to diagnose based on hematoxylin-eosin and Alcian blue-periodic acid-Schiff staining. Furthermore, we analyzed the clinicopathological characteristics and prognoses of these 2 subtypes. LD type was a poor prognostic factor on univariate analysis; it had significantly worse overall survival ( P = 0.007) and recurrence-free survival ( P < 0.001) than the SD type. In conclusion, we propose new subclassification criteria for iCCA based on immunostaining of S100P and OPN. These criteria may help pathologists to diagnose subtypes of iCCA, supporting future clinical trials and the development of medications for these 2 subtypes as distinct cancers.

Long-term remnant liver volume dynamics after major hepatectomy for perihilar cholangiocarcinoma following portal vein embolization.

BACKGROUND: Portal vein embolization (PVE) followed by major hepatectomy is a common treatment strategy for patients with perihilar cholangiocarcinoma (PHCC); however, the long-term dynamics of the liver remnant volume (LRV) remain unclear. Here, we report the dynamics of the LRV in patients who underwent hepatectomy following PVE. METHODS: A total of 39 patients with PHCC who underwent right hemihepatectomy or left trisectionectomy with extrahepatic bile duct resection between 2004 and 2021 were enrolled in this study [PVE (n = 27) and non-PVE (n = 12]). Long-term remnant liver dynamics were analyzed in propensity score-matched pairs (n = 10/group). RESULTS: The LRV/future liver remnant volume (FLRV) at 1 week to 1 month after hepatectomy were smaller in the PVE group than in the non-PVE group (1.53 vs. 1.69, p = .044 and 1.52 vs 1.99, p = .003, respectively). In the non-PVE group, the LRV/FLRV ratio plateaued 1-3 months postoperatively, whereas progressive hypertrophy occurred in the PVE group, and the LRV/FLRV ratio became equal in both groups at 1 year after hepatectomy (1.96 vs. 1.97; p = .799). Multivariate analysis revealed that FLRV/total liver volume (TLV) ≤ 0.43 was the only independent predictor of LRV/FLRV ≥1.9 at 1 year after hepatectomy (odds ratio:5.345, 95% confidence interval:1.210-23.615; p = .027). CONCLUSION: Although the long-term LRV was nearly equal in both groups, short-term LRV hypertrophy was lower in the PVE group than in the non-PVE group.

Primary spindle cell tumor originating from the liver that was difficult to diagnose.

BACKGROUND: It has been reported that hepatocellular carcinoma (HCC) with spindle cell tumor accounts for 1.8% of all HCCs, but spindle cell tumors that do not show an obvious conventional HCC are extremely rare. In this report, we describe a case of resection of a primary spindle cell tumor of the liver that was difficult to diagnose. CASE PRESENTATION: A 75-year-old man presented with fever and right chest pain. He was suspected of a giant primary diaphragmatic tumor of extrahepatic origin by imaging studies. The preoperative differential diagnosis included benign masses such as myxoid sarcoma and schwannoma, and we planned a diaphragmatic resection. Intraoperatively, however, dissection of the tumor from the liver was not possible, requiring an extended right posterior segmentectomy with combined resection of the diaphragm. The patient had a good postoperative course and 1 year has passed since the surgery with no recurrence. The pathology showed that the mass was located just below the hepatic capsule/parenchymal region and was adherent to the diaphragm, but there was no continuity. The morphology suggested a low-grade mesenchymal tumor such as a solitary fibrous tumor and perivascular epithelioid cell tumor, but immunostaining was negative, making the diagnosis difficult. Although some areas of high proliferative activity were observed, finally, the diagnosis of primary spindle cell tumor of the liver with smooth muscle differentiation was made based on the positive results of muscle markers such as αSMA, desmin, and h-caldesmon. CONCLUSIONS: Spindle cell tumor arising from the liver is so rare that preoperative and pathological diagnosis is often difficult to reach. Although further studies are needed to elucidate and better understand this uncommon clinical entity, we consider that complete resection is necessary for the above case, which may contribute to long-term survival.

Fatal disseminated mucormycosis due to Cunninghamella bertholletiae infection after ABO-incompatible living donor liver transplantation: a case report.

BACKGROUND: Fungal infection may develop because of immunosuppression after organ transplantation, in which invasive types, such as Aspergillus and Mucorales, fungi cause morbidity. We present a case of disseminated mucormycosis due to Cunninghamella bertholletiae after ABO-incompatible living donor liver transplantation (LDLT). CASE PRESENTATION: A 47-year-old man with decompensated liver cirrhosis and hepatocellular carcinoma underwent an ABO-incompatible LDLT using a graft procured from his son, who had a different blood type. Rituximab and mycophenolate mofetil were administered 3 weeks before LDLT as immunosuppressive therapy. Although liver graft function improved, mass-like infiltrates appeared in the lungs following intubation for > 1 week due to impaired consciousness. The brain magnetic resonance imaging findings were normal. Decreased ejection fraction and ST elevation were detected on echocardiography and electrocardiography, respectively. There was no dominant stenosis on coronary arteriography. The recipient underwent segmentectomy of the right lung 20 days after LDLT. C. bertholletiae was identified from a specimen using polymerase chain reaction, thus establishing a diagnosis of mucormycosis. Multiple infarctions in the brain, heart, and kidney developed within 2 weeks. Treatment with amphotericin B was ineffective. The patient developed circulatory collapse, and a temporary pacemaker and percutaneous coronary intervention were required for cardiac infarction. The recipient died of cardiac failure 27 days after the LDLT. Autopsy revealed disseminated mucormycosis involving the brain, thyroid, heart, lung, liver, gastrointestinal tract, and both kidneys. In addition, fungal endocarditis may have been responsible for septic emboli in multiple organs, resulting in multiple organ invasion. Hypothrombocytopenia was present since the pre-transplant period, and the recipient was diagnosed posthumously with myelodysplastic syndrome due to hereditary abnormalities. Multiple factors such as organ transplantation, bone marrow dysfunction, immunosuppression, and inadequate administration of antifungal reagents might have promoted mucormycosis development in our patient. CONCLUSIONS: Mucormycosis by C. bertholletiae is a fatal complication; thus, early diagnosis and treatment are warranted before multiple organ invasion.