Keiichi Kinowaki

Abernethy malformation is a rare congenital extrahepatic mesocaval shunt (CEMS) in which mesenteric venous blood bypasses the liver completely (type I) or partially (type II) and drains directly into the vena cava. In complete CEMS (type I), the intrahepatic portal vein is absent. The resulting lack of portal flow is associated with the development of hepatic nodules, such as focal nodular hyperplasia (FNH), hepatocellular adenoma (HCA), and hepatocellular carcinoma (HCC). These lesions have a higher risk of malignant transformation than conventional adenomas. The term hepatocellular neoplasm of uncertain malignant potential (HUMP) has been proposed for borderline lesions between HCA and well‐differentiated HCC, diagnosed based on atypical histological, genetic, or clinical features suggesting a possible malignant potential. However, the exact risk of malignant transformation is unknown. We present the case of a 32‐year‐old man with Type I Abernethy malformation who developed malignant transformation of a HUMP over a 15‐year period. Serial hepatic resections performed at other institutions demonstrated histological progression from HUMP to HCC with subsequent lung metastasis. This gradual transformation has been documented in several surgical specimens. This case highlights the need for careful recognition of HUMP in patients with Abernethy malformation, as timely liver transplantation may be essential to prevent malignant transformation and achieve curative outcomes.

Background: Solitary fibrous tumors (SFT) are uncommon mesenchymal neoplasms which can arise in any anatomical location. Pleural SFTs have been most frequently documented; however, breast SFT is an exceedingly rare entity and seldom present in male breast, with only 8 previously reported cases. Recently, STAT6 immunostaining was considered to be a definitive marker of SFT, however, no case of the male breast SFT showing STAT6 positivity preoperatively has been reported. Methods and Results: We describe a case of breast SFT in a 73-year-old male patient with a 12-month history of a palpable breast mass. The only associated clinical symptom was bilateral gynecomastia. An ultrasound scan examination revealed an oval, well-circumscribed and hypoechoic mass with hypervascularity. A core-needle biopsy was performed, and microscopic examination with immunohistochemistry confirmed the diagnosis of SFT. He underwent a complete surgical resection with clear margins, and there were no signs of high cellularity, remarkable mitotic activity, pleomorphism, hemorrhage or necrosis. Conclusion: A perioperative immunohistochemical evaluation for diffuse and intense nuclear expression of STAT6 was helpful to distinguish SFT from myofibroblastoma. We, herein, describe the first case of SFT in a male breast, confirmed by STAT6 immunostaining positivity. We also conducted a literature review of all previous cases of breast SFTs.

Introduction: The effectiveness of nivolumab plus ipilimumab for metastatic renal cell carcinoma with inferior vena cava tumor thrombus remains unclear.Case presentation: A 75‐year‐old male was diagnosed with metastatic renal cell carcinoma with inferior vena cava tumor thrombus and treated with nivolumab plus ipilimumab. The renal mass and thrombus regressed and all pulmonary nodules except for one lesion diminished. To avoid thrombotic complications, radical nephrectomy and thrombectomy were performed. No viable malignant cells were revealed histopathologically. Although nivolumab was continued after the surgical interventions, the remaining lesion did not change. Considering the discontinuation of nivolumab, metastasectomy was performed, and no viable malignant cells were revealed histopathologically. There has been no recurrence after the discontinuation.Conclusion: Nivolumab plus ipilimumab could have effectiveness for metastatic renal cell carcinoma with inferior vena cava tumor thrombus.

Tripartite motif (TRIM) family proteins are involved in various biological processes and the pathophysiology of cancers. However, the roles of TRIM39, a TRIM family member, in breast cancer is not well‐understood. Here, we performed immunohistochemical study of TRIM39 protein in clinical estrogen receptor‐positive (ER⁺) breast cancer tissues from 108 patients. TRIM39 immunoreactivity (IR) was positively correlated with advanced stage (p < 0.001), large invasive tumor size (p = 0.012), and positive lymph node status (p = 0.002). Positive TRIM39 IR was significantly correlated with short disease‐free survival (DFS) (p = 0.001). Multivariate analysis revealed that the TRIM39 status is an independent prognostic factor in DFS (p = 0.049). Microarray analysis of MCF‐7 breast cancer cells treated with siRNA revealed that TRIM39 knockdown downregulated the cell cycle‐ and cell division‐related genes, including MLLT11, CDCA3, CDC25C, BIRC5, and ANP32E. Consistently, TRIM39 knockdown significantly suppressed proliferation and cell cycle transition to S phase in MCF‐7 and 4‐hydroxytamoxifen‐resistant (OHTR) breast cancer cells. These results suggest that TRIM39 promotes ER⁺ breast cancer growth by promoting cell cycle progression.

Octamer transcription factor 1 (OCT1) is a transcriptional factor reported to be a poor prognostic factor in various cancers. However, the clinical value of OCT1 in breast cancer is not fully understood. In the present study, an immunohistochemical study of OCT1 protein was performed using estrogen receptor (ER)-positive breast cancer tissues from 108 patients. Positive OCT1 immunoreactivity (IR) was associated with the shorter disease-free survival (DFS) of patients (p = 0.019). Knockdown of OCT1 inhibited cell proliferation in MCF-7 breast cancer cells as well as its derivative long-term estrogen-deprived (LTED) cells. On the other hand, the overexpression of OCT1 promoted cell proliferation in MCF-7 cells. Using microarray analysis, we identified the non-structural maintenance of chromosomes condensin I complex subunit H (NCAPH) as a novel OCT1-taget gene in MCF-7 cells. Immunohistochemical analysis showed that NCAPH IR was significantly positively associated with OCT1 IR (p < 0.001) and that positive NCAPH IR was significantly related to the poor DFS rate of patients (p = 0.041). The knockdown of NCAPH inhibited cell proliferation in MCF-7 and LTED cells. These results demonstrate that OCT1 and its target gene NCAPH are poor prognostic factors and potential therapeutic targets for patients with ER-positive breast cancer.

Introduction Cystic partially differentiated nephroblastoma is a multilocular cystic variant of Wilms tumor that always presents in children. However, we encountered an elderly patient with cystic partially differentiated nephroblastoma. Therefore, we report it. Case presentation A 74-year-old male presented with a left renal tumor detected with ultrasonography. Contrast-enhanced computed tomography and magnetic resonance imaging revealed a 4 cm multilocular cystic tumor with septa, which suggested multilocular cystic renal cell carcinoma. Therefore, we performed a radical nephrectomy. The definitive diagnosis of cystic partially differentiated nephroblastoma was made with histopathological findings. After the surgical resection, no recurrence has occurred in the past 13 years. Conclusion Cystic partially differentiated nephroblastoma can develop in adults, regardless of age. Furthermore, surgical resection can be used as an established treatment option in adult cystic partially differentiated nephroblastoma cases.