Pathology International最新文献

Linear nevus sebaceous syndrome (LNSS) is a neurocutaneous syndrome associated with systemic complications that involve multiple organs, including the skin, central nervous system, eyes, and skeleton. LNSS is considered to be caused by mosaic RAS gene mutation. In this report, we present an autopsy case of LNSS in a Japanese boy. The affected neonate had hydrops fetalis and was born at 28 weeks and 4 days of gestation, weighing 2104 g. He had bilateral inverted eyelids, verrucous linear nevus separated along Blaschko's line, myocardial hypertrophy, and pharyngeal constriction, and underwent intensive treatment in NICU for arrhythmia, hydrocephalus, and respiratory distress. The hydrocephalus progressed gradually and he died at the age of 181 days, 12 days after a sudden cardiac arrest and recovery. KRAS G12D mutation was found in a skin biopsy specimen but not in blood cells, suggesting a postzygotic mosaicism. Autopsy revealed novel pathological findings related to LNSS, including intracranial lipomatous hamartoma and mesenteric lymphangioma, in addition to previously reported findings such as multicystic dysplastic kidney. There was the limited expression of mutated KRAS protein in kidneys.

Currently, there are more than 10 million patients with diabetes mellitus in Japan. Therefore, the need to explore the pathogenesis of diabetes and the complications leading to its cure is becoming increasingly urgent. Pathological examination of pancreatic tissues from patients with type 2 diabetes reveals a decrease in the volume of beta cells because of a combination of various stresses. In human type 2 diabetes, islet amyloid deposition is a unique pathological change characterized by proinflammatory macrophage (M1) infiltration into the islets. The pathological changes in the pancreas with islet amyloid were different according to clinical factors, which suggests that type 2 diabetes can be further subclassified based on islet pathology. On the other hand, diabetic peripheral neuropathy is the most frequent diabetic complication. In early diabetic peripheral neuropathy, M1 infiltration in the sciatic nerve evokes oxidative stress or attenuates retrograde axonal transport, as clearly demonstrated by in vitro live imaging. Furthermore, islet parasympathetic nerve density and beta cell volume were inversely correlated in type 2 diabetic Goto-Kakizaki rats, suggesting that diabetic peripheral neuropathy itself may contribute to the decrease in beta cell volume. These findings suggest that the pathogenesis of diabetes mellitus and diabetic peripheral neuropathy may be interrelated.

Clear cell hidradenoma is a rare benign tumor of the breast, its origin and pathogenesis are controversial. We have experienced a case of breast clear cell hidradenoma with mastermind like transcriptional coactivator 2 (MAML2) gene rearrangement. The patient found a painless mass with a hard texture in the left breast areola without nipple discharge. Microscopically, the tumor was cystic and solid, locally arranged in a glandular structure, covered by single cuboidal cells; it was composed of clear cells, epidermoid cells, and basaloid cells; there were no necrosis or mitotic figures. Immunohistochemical staining showed that the tumor cells positively expressed low-molecular cytokeratin 7, low-molecular cytokeratins (Cam5.2), high-molecular cytokeratin 5/6, cytokeratin 14, CD117, and p63; and did not express calponin, and smooth muscle myosin heavy chain. The cuboidal cells were positive for SOX10 but negative for p63. Additionally, periodic acid-Schiff reaction showed purple-red granules in the tumor cytoplasm, but Alcian blue staining showed no blue mucus in the cytoplasm. The split signals of MAML2 gene were detected by fluorescence in situ hybridization. Subtle histological and immunophenotypical differences may help to distinguish breast clear cell hidradenoma from common breast tumors. Furthermore, the MAML2 gene rearrangement may be a molecular genetic characteristic of breast clear cell hidradenoma.

"Cysts of the ligamentum flavum (cysts-LF)" is the term for non-neoplastic cystic lesion involving LF. The aim of the present study was to elucidate the histopathological characteristics and pathogenesis of "cysts-LF". Herein, we defined cysts-LF as spinal cysts containing degenerative LF components. From archival cases, we investigated 18 symptomatic cysts-LF surgically removed from 18 patients (13 males and five females; median age 68.5 years [range, 42-86 years]). The elastic fibers of LF components in the wall were separated and/or torn, and cyst walls were accompanied by chondroid metaplasia (17 cases), myxoid changes (13 cases), ossification (11 cases), amyloid deposits (14 cases), hemosiderosis (six cases), granular/smudgy calcification (four cases), synovial cell linings (three cases), and severe inflammatory infiltrates (one case). These histologic features of our cysts-LF were shared by previously reported "cysts-LF." Fourteen cysts-LF demonstrated vascular stenosis/occlusion, and eight showed thick hyalinized vessels, suggesting local circulatory insufficiency. Eight cases (44%) exhibited lipomembranous fat necrosis, accompanied by hyalinized vascular changes (p = 0.003). Ischemic conditions were observed in nearly half of the present cysts-LF, and may be one of the main contributing factors for the formation of cysts-LF, via degeneration and cystic changes in the LF.

Eukaryotic elongation factor 1 alpha 2 (eEF1A2) encodes an isoform of the alpha subunit of the elongation factor 1 complex and is responsible for the enzymatic delivery of aminoacyl tRNA to the ribosome. Our proteomic analysis has identified eEF1A2 as one of the proteins expressed during malignant progression from adenocarcinoma in situ (AIS) to early invasive lung adenocarcinoma. The expression level of eEF1A2 in 175 lung adenocarcinomas was examined by immunohistochemical staining in relation to patient prognosis and clinicopathological factors. Quantitative PCR analysis and fluorescence in situ hybridization (FISH) were performed to evaluate the amplification of the eEF1A2 gene. Relatively high expression of eEF1A2 was observed in invasive adenocarcinoma (39/144 cases) relative to minimally invasive adenocarcinoma (1/10 cases) or AIS (0/21 cases). Among invasive adenocarcinomas, solid-type adenocarcinoma (15/32 cases, 47%) showed higher expression than other histological subtypes (23/92, 25%). Patients with eEF1A2-positive tumors had a significantly poorer prognosis than those with eEF1A2-negative tumors. Of the five tumors that were eEF1A2-positive, two cases showed amplified genomic eEF1A2 DNA, which was confirmed by both qPCR and FISH. These findings indicate that eEF1A2 overexpression occurs in the course of malignant transformation of lung adenocarcinomas and is partly due to eEF1A2 gene amplification.

Exosomes from cancer cells function as carriers to spread or transport specific microRNAs (miRNAs) to distant sites to exert their effects, but the mechanism of exosomal miRNA action in esophageal squamous cell carcinoma (ESCC) has not been fully explained. Therefore, in this study, we were interested in the impact of exosomal miR-196a-5p in ESCC progression. We found that miR-196a-5p was expressed enriched in clinical tissues, ESCC cells, and exosomes. Functionally, depletion of miR-196a-5p impeded ESCC cell growth, migration, and invasion, whereas overexpression of miR-196a-5p produced the opposite results. Moreover, enhancement of exosomal miR-196a-5p in recipient ESCC cells triggered more intense proliferation and migration. Mechanistically, we identified integral membrane protein 2B (ITM2B) as a direct target of miR-196a-5p. Silencing of ITM2B partially counteracted the inhibitory effect of miR-196a-5p inhibitors on the malignant phenotype of ESCC. Furthermore, in vivo, lower miR-196a-5p levels triggered by the introduction of antagomiR-196a-5p resulted in the generation of smaller volume and weight xenograft tumors. Thus, our results demonstrated novel mechanisms of exosomal and intracellular miR-196a-5p-mediated ESCC growth and migration and identify the interaction of miR-196a-5p with ITM2B. These works might provide new targets and basis for the development of clinical treatment options for ESCC.

Reports of Helicobacter pylori (Hp)-naïve gastric neoplasm (HpNGN) cases have been rapidly increasing due to the recent increase in the Hp-naïve population in Japan. Most HpNGNs exhibit the gastric immunophenotype and a low malignant potential regardless of histological type. Especially, foveolar-type gastric adenoma (FGA) and intestinal-type gastric dysplasia (IGD) rarely progress to invasive carcinoma. FGA is a foveolar epithelial neoplasm that occurs in the fundic gland (oxyntic gland) mucosa and is classified as the flat type or raspberry type (FGA-RA). The flat type is a large, whitish flatly elevated lesion while FGA-RA is a small reddish polyp. Genomically, the flat type is characterized by APC and KRAS gene mutations and FGA-RA by a common single nucleotide variant in the KLF4 gene. This KLF4 single-nucleotide variant reportedly induces gastric foveolar epithelial tumorigenesis and activates both cell proliferation and apoptosis, leading to its slow-growing nature. IGD consists of an intestinalized epithelial dysplasia that develops in the pyloric gland mucosa, characterized as a superficial depressed lesion surrounded by raised mucosa showing a gastritis-like appearance. Immunohistochemically, it exhibits an intestinal or gastrointestinal phenotype and, frequently, p53 overexpression. Thus, IGD shows unique characteristics in HpNGNs and a potential multistep tumorigenic process.

Leucine-rich repeat-containing G protein-coupled receptor 5 (LGR5), a significant cancer stem cell marker in colorectal cancer (CRC), lacks lymph node (LN) expression studies. In this study, we identified LGR5 expression by RNAscope, a highly sensitive RNA in situ method, and analyzed its association with clinicopathological characteristics. Tissue microarrays were generated from primary tumors (PTs) and LN metastases in paraffin-embedded blocks of 38 CRC surgical resection materials. LGR5 expression by RNAscope was evaluated by dividing the expression levels into negative and positive expression. In all but two cases of LN metastasis, LGR5-positive dots were detected in tumor cells, and there was a wide range of LGR5-positive cells. More LGR5-positive dots were identified in the gland-forming region. Twenty-three cases were classified into a high LGR5-expression group, and 15 cases were classified into a low LGR5-expression group. In the high LGR5-expression group, the histological grade was lower than in the low LGR5-expression group (p = 0.0159), while necrosis was significantly more prevalent (p = 0.0326), and the tumor, node, metastasis stage was significantly lower (p = 0.0302). There was no association between LGR5 expression levels in LN metastases and LGR5 expression levels in PT tissue. LGR5 expression in LN metastases may influence prognosis. Further analysis may lead to new therapeutic strategies.

We conducted an autopsy on a 3-month-old boy in whom Kawasaki disease (KD) was strongly suspected based on the autopsy findings. The infant had a fever and was brought to a nearby clinic, where he was prescribed antipyretics and kept under observation. However, 15 days after onset of the fever, he suddenly died in bed. He exhibited no obvious redness of the lips, tongue, or conjunctiva. Membranous desquamation was present on his distal fingers. Vasculitis was observed in the coronary arteries, renal artery, splenic artery, and pulmonary vein. In addition, coronary artery aneurysms were present in the right coronary artery and left anterior descending artery. Thrombotic occlusion was observed in one aneurysm in the right coronary artery, resulting in acute myocardial infarction. The coronary artery wall showed infiltration of numerous macrophages and neutrophils. This case was classified as incomplete KD because the coronary artery aneurysm could not be demonstrated before death and was only recognized at autopsy. Pathologists and forensic scientists need to be aware that there are cases in which KD goes undiagnosed and untreated, leading to coronary artery aneurysm formation and sudden death.