Small Insulinoma Followed-up as an Indolent Pancreatic Tumor: A Case Report

A woman in her 60s presented with a small pancreatic head tumor. Imaging studies revealed a 13-mm well-defined pancreatic head tumor. A neuroendocrine neoplasm was suspected, and the patient opted for observation at that time. After 8 months, the patient began experiencing sweating while fasting, and blood tests during regular follow-up visits showed hypoglycemia. Hypoglycemia was induced during fasting test. The tumor exhibited clear features of an insulinoma during follow-up observation. While small neuroendocrine neoplasms are often managed through observation, caution should be exercised regarding their transformation into functional neuroendocrine tumors.

Radiation-Associated Breast Angiosarcoma

Radiation-associated breast angiosarcomas are rare following breast-conserving surgery. These angiosarcomas are considered adverse events associated with radiation therapy and are characterized by a high risk of both local and distant recurrence, even after complete resection. Despite this, there is currently no established standard treatment for them. The patient was a 70-year-old woman who had breast-conserving surgery for right breast cancer 10 years before presentation. She was followed up for 10 years after receiving 50 Gy of residual breast irradiation and an aromatase inhibitor for 5 years. During follow-up, a painless purplish area with induration, measuring 10 cm by 5.4 cm, was noted on the right nipple. A skin biopsy confirmed hemangiosarcoma. Treatment included surgery with a 2.0 cm margin from the area, followed by skin excision and total mastectomy. A final diagnosis of radiation-associated breast angiosarcoma was made. Radiation-associated breast angiosarcoma is a rare disease with a poor prognosis that lacks standard treatment. An aggressive skin biopsy should be considered when skin findings such as purpura are seen after breast cancer radiotherapy, as in this case.

Subareolar Breast Abscess in a Male: A Case Report

A subareolar breast abscess (SBA) is caused by the formation of an inflammatory abscess around the milk duct. SBAs usually occur in females, and reports of SBAs in males are very rare. This study reports the case of a 62-year-old male patient who presented with a subcutaneous nodule and diffuse erythema around the left nipple. Ultrasonography revealed a mixed lesion measuring 2.5 x 1.5 cm, mostly cystic. A computed tomography scan of the chest showed an irregular, nodular structure in the same area. Magnetic resonance imaging with contrast enhancement suggested an abscess. A needle biopsy was performed on the lesion, and results showed moderate inflammatory cell infiltration, including lymphocytes, plasma cells, neutrophils, and abscess formation, thus leading to the diagnosis of SBA. The patient did not strongly desire a surgical procedure. He was treated with the cephem antibiotic cefaclor and antipyretic analgesics. During the six-month healing period, cefaclor was administered for a total of six weeks. Once he improved, recurrence was observed two years after the onset of the disease; however, the symptoms improved with conservative treatment, such as warm compresses. Preventive measures should be considered as SBAs are prone to recurrence.

A case of lymphoma mimicking infected internal iliac artery aneurysm

BACKGROUND

Malignant lymphoma rarely mimics an infected arterial aneurysm and a ruptured arterial aneurysm because of similar imaging findings, leading to misdiagnosis. The hematomas of ruptured aneurysms are radiologically difficult to distinguish from those of malignant lymphoma in emergency settings. Hence, a definitive diagnosis is crucial to avoid unnecessary surgery.

CASE PRESENTATION

A man in his 80s with hematuria and shock vital had right internal iliac artery aneurysm (IIAA) and perianeurysmal fluid retention, which appeared to be a ruptured or an infected aneurysm. Treatment was initiated for infected IIAA instead of for ruptured IIAA. Systemic inflammatory response syndrome developed, and the infectious sources were assessed. Pacemaker lead and urinary tract infections were identified and treated; however, blood pressure was unstable. The aneurysm was treated with endovascular aortic aneurysm repair following antibiotic therapy; however, fluid retention increased, and inflammatory status and hematuria deteriorated. Open surgical conversion was performed to manage the infected lesions. Although an iliopsoas abscess was detected during surgery and nephrectomy and ureterectomy were performed to control the hematuria, analysis of the removed tissues led to the pathological diagnosis of diffuse large B-cell lymphoma (DLBCL).

CONCLUSIONS

We encountered a case of DLBCL with imaging findings mimicking an infected internal iliac artery aneurysm, and definitive diagnosis was made more than 2 months after the initial examination. Definitively diagnosing malignant lymphoma around an iliac artery aneurysm based merely on symptoms and imaging findings is extremely difficult. Thus, histological examination should be actively performed in atypical infected aneurysms.

Gastro-colic Fistula-associated Hypersplenism Causes Pancytopenia in a Patient with Crohn's Disease

A 24-year-old woman was admitted to our hospital due to abdominal pain and a high fever. She was diagnosed with ileocolonic Crohn's disease (CD), complicated with a gastro-colic fistula and splenomegaly. After initial treatment with an infliximab-biosimilar, all blood cell line counts markedly decreased. Three-dimensional reconstructed computed tomography revealed splenic vein narrowing. Thus, her pancytopenia was deemed to have likely been caused by hypersplenism. Surgery was performed, and clinical remission was maintained without pancytopenia. This is the first report of a CD patient with pancytopenia caused by hypersplenism that was triggered by gastro-colic fistula-associated splenic vein obstruction.

Subcellular localization of hTERT in breast cancer: insights into its tumorigenesis and drug resistance mechanisms in HER2-immunopositive breast cancer

Human telomerase reverse transcriptase (hTERT) is highly expressed in various cancers, including breast cancer. Although telomere elongation is an essential role for hTERT, the nuclear export after oxdative stress has also been shown in several cancer cell lines and is associated with drug-resistance in vitro. As only a few reports focused on the subcellular localization of hTERT in clinical specimens, we performed immunohistochemistry (IHC) and analyzed the correlation between intracellular hTERT expression and the clinicopathological characteristics to identify the clinical significance of hTERT subcellular expression in breast cancers. 144 invasive breast cancers classified by IHC subtype without primary systemic therapy (PST), were selected from a surgical resection cohort and were immunostained for hTERT, p-STAT3, p-AKT and p-ERK. The nuclear and/or cytoplasmic staining intensity and proportion of hTERT were scored and compared with clinicopathological parameters. The nuclear hTERT expression was significantly correlated with HER2 expression (p = 0.00156), and the scores were significantly correlated with p-STAT3 and p-AKT expression scores (r = 0.532, p = 0.000587 and r = 0.345, p = 0.0339, respectively) in the HER2-immunopositive breast cancer including luminal-HER2 and HER2 subtypes. Furthermore, hTERT was expressed more in cytoplasm in the specimens after PST than those before PST, and the score tended to be negatively correlated with tumor shrinkage rate in HER2 subtype (r = -0.593, p = 0.0705). These results suggest that nuclear and/or cytoplasmic hTERT may play a different role before and after PST including the tumorigenesis and drug-resistance in breast cancer. Suppression of cytoplasmic hTERT expression may lead to more effective strategy for drug-resistant HER2 subtype in breast cancer.

Generation of combined hepatocellular-cholangiocarcinoma through transdifferentiation and dedifferentiation in p53-knockout mice

The two principal histological types of primary liver cancers, hepatocellular carcinoma (HCC) and cholangiocarcinoma, can coexist within a tumor, comprising combined hepatocellular‐cholangiocarcinoma (cHCC‐CCA). Although the possible involvement of liver stem/progenitor cells has been proposed for the pathogenesis of cHCC‐CCA, the cells might originate from transformed hepatocytes that undergo ductular transdifferentiation or dedifferentiation. We previously demonstrated that concomitant introduction of mutant HRAS^V12 (HRAS) and Myc into mouse hepatocytes induced dedifferentiated tumors that expressed fetal/neonatal liver genes and proteins. Here, we examine whether the phenotype of HRAS‐ or HRAS/Myc‐induced tumors might be affected by the disruption of the Trp53 gene, which has been shown to induce biliary differentiation in mouse liver tumors. Hepatocyte‐derived liver tumors were induced in heterozygous and homozygous p53‐knockout (KO) mice by hydrodynamic tail vein injection of HRAS‐ or Myc‐containing transposon cassette plasmids, which were modified by deleting loxP sites, with a transposase‐expressing plasmid. The HRAS‐induced and HRAS/Myc‐induced tumors in the wild‐type mice demonstrated histological features of HCC, whereas the phenotype of the tumors generated in the p53‐KO mice was consistent with cHCC‐CCA. The expression of fetal/neonatal liver proteins, including delta‐like 1, was detected in the HRAS/Myc‐induced but not in the HRAS‐induced cHCC‐CCA tissues. The dedifferentiation in the HRAS/Myc‐induced tumors was more marked in the homozygous p53‐KO mice than in the heterozygous p53‐KO mice and was associated with activation of Myc and YAP and suppression of ERK phosphorylation. Our results suggest that the loss of p53 promotes ductular differentiation of hepatocyte‐derived tumor cells through either transdifferentiation or Myc‐mediated dedifferentiation.

Decreased Portal Circulation Augments Fibrosis and Ductular Reaction in Nonalcoholic Fatty Liver Disease in Mice

Nonalcoholic fatty liver disease often progresses to cirrhosis and causes liver cancer, but mechanisms of its progression are yet to be elucidated. Although nonalcoholic fatty liver disease is often associated with abnormal portal circulation, there have not been any experimental studies to test its pathogenic role. Here, whether decreased portal circulation affected the pathology of nonalcoholic steatohepatitis (NASH) was examined using congenital portosystemic shunt (PSS) in C57BL/6J mice. Whereas PSS significantly attenuated free radical-mediated carbon tetrachloride injury, it augmented pericellular fibrosis in the centrilobular area induced by a 0.1% methionine choline-deficient l-amino acid-defined high-fat diet (CDAHFD). PSS aggravated ductular reaction and increased the expression of connective tissue growth factor. Pimonidazole immunohistochemistry of the liver revealed that the centrilobular area of PSS-harboring mice was more hypoxic than that of control mice. Although tissue hypoxia was observed in the fibrotic area in CDAHFD-induced NASH in both control and PSS-harboring mice, it was more profound in the latter, which was associated with higher carbonic anhydrase 9 and vascular endothelial growth factor expression and neovascularization in the fibrotic area. Furthermore, partial ligation of the portal vein also augmented pericellular fibrosis and ductular reaction induced by a CDAHFD. These results demonstrate that decreased portal circulation, which induces hypoxia due to disrupted intralobular perfusion, is an important aggravating factor of liver fibrosis in NASH.

Long-term Observation of Gastric Adenocarcinoma of Fundic Gland Mucosa Type before and after Helicobacter pylori Eradication: a Case Report

Gastric adenocarcinoma of the fundic gland mucosa type (GA-FGM) was proposed as a new variant of gastric adenocarcinoma of the fundic gland type (GA-FG). However, at present, the influence of Helicobacter pylori and the speed of progression and degree of malignancy in GA-FGM remain unclear. Herein, we report the first case of intramucosal GA-FGM that was endoscopically observed before and after H. pylori eradication over 15 years. The lesion showed the same tumor size with no submucosal invasion and a low MIB-1 labeling index 15 years after its detection using endoscopy. The endoscopic morphology changed from 0-IIa before H. pylori eradication to 0-IIa+IIc and then 0-I after H. pylori eradication. These findings suggest that the unaltered tumor size reflects low-grade malignancy and slow growth, and that the endoscopic morphology is influenced by H. pylori eradication.