[Giant Bullae Misdiagnosed as Pneumothorax:Report of a Case].

A 46-year-old man was taken to a hospital by ambulance because of sudden onset of dyspnea, and was inserted chest drainage tube with a diagnosis of right-sided tension pneumothorax on chest X-ray. Since the chest drainage was not effective, he was transferred to our institute. Based on chest computed tomography (CT) findings, a diagnosis of giant bullae of the right lung was made, and surgical treatment was performed. Postoperatively, the improvement of respiratory function was confirmed.

Bronchogenic cyst with atypical imaging findings and repeated ruptures in a short period of time: A case report.

Bronchogenic cysts are the most common primary cysts of the mediastinum. Although most are asymptomatic, some bronchogenic cysts cause symptoms such as chest pain and dyspnea. Here, we report a case of bronchogenic cyst that ruptured twice in a short period of time in a patient who presented with sudden back pain. The lesion was apparent on computed tomography (CT) as a mass lesion with heterogeneous and high attenuation in the posterior mediastinal region. CT-guided puncture performed for diagnostic purposes revealed the contents as bloody fluid. The patient suffered chest pain approximately 3 months after the first presentation, and re-growth and re-rupture of the mass was suspected. The lesion was surgically resected and pathologically diagnosed as a bronchogenic cyst. Spontaneous rupture is a very rare complication of bronchogenic cyst, usually into the trachea, pleural cavity, or pericardial cavity. However, there are no reports of multiple ruptures. This case highlights the importance of recognizing the atypical imaging findings of bronchogenic cyst and the rare complication of rupture.

Small-cell neuroendocrine carcinoma of the cervix accompanied by adenocarcinoma and high-grade squamous intraepithelial lesion.

Few cytological reports have described small-cell neuroendocrine carcinoma (SCNEC) in the female genital tract. In the present study, we describe a cytological case of SCNEC accompanied by adenocarcinoma, as well as high-grade squamous intraepithelial lesion (HSIL). A Japanese woman (42 years old) presented with abnormal genital bleeding. A conventional Papanicolaou smear revealed an inflammatory condition with three neoplastic components: SCNEC as irregular aggregates of neoplastic small round cells with nuclear molding and granular chromatin; adenocarcinoma as columnar cell clusters with peripherally located large nuclei, and HSIL as sheets or clusters of dysplastic basal-type squamous cells with irregular hyperchromatic nuclei. Accordingly, a cytodiagnosis of SCNEC with adenocarcinoma and HSIL was made. Owing to the rarity of cervical SCNEC, cytological diagnosis may be difficult. Due to its aggressive clinical behavior, the presence of an SCNEC component should be verified in any cytodiagnosis of adenocarcinoma or HSIL.

Histology of Cardiac Sarcoidosis with Novel Considerations Arranged upon a Pathologic Basis.

Sarcoidosis is a rare disease of isolated or diffuse granulomatous inflammation. Although any organs can be affected by sarcoidosis, cardiac sarcoidosis is a fatal disorder, and it is crucial to accurately diagnose it to prevent sudden death due to dysrhythmia. Although endomyocardial biopsy is invasive and has limited sensitivity for identifying granulomas, it is the only modality that yields a definitive diagnosis of cardiac sarcoidosis. It is imperative to develop novel pathological approaches for the precise diagnosis of cardiac sarcoidosis. Here, we aimed to discuss commonly used diagnostic criteria for cardiac sarcoidosis and to summarize useful and novel histopathologic criteria of cardiac sarcoidosis. While classical histologic observations including noncaseating granulomas and multinucleated giant cells (typically Langhans type) are the most important findings, others such as microgranulomas, CD68+ CD163- pro-inflammatory (M1) macrophage accumulation, CD4/CD8 T-cell ratio, Cutibacterium acnes components, lymphangiogenesis, confluent fibrosis, and fatty infiltration may help to improve the sensitivity of endomyocardial biopsy for detecting cardiac sarcoidosis. These novel histologic findings are based on the pathology of cardiac sarcoidosis. We also discussed the principal histologic differential diagnoses of cardiac sarcoidosis, such as tuberculosis myocarditis, fungal myocarditis, giant cell myocarditis, and dilated cardiomyopathy.

Frequent genetic alterations in immune checkpoint-related genes in intravascular large B-cell lymphoma.

Intravascular large B-cell lymphoma (IVLBCL) is a unique type of extranodal lymphoma characterized by selective growth of tumor cells in small vessels without lymphadenopathy. Greater understanding of the molecular pathogenesis of IVLBCL is hampered by the paucity of lymphoma cells in biopsy specimens, creating a limitation in obtaining sufficient tumor materials. To uncover the genetic landscape of IVLBCL, we performed whole-exome sequencing (WES) of 21 patients with IVLBCL using plasma-derived cell-free DNA (cfDNA) (n = 18), patient-derived xenograft tumors (n = 4), and tumor DNA from bone marrow (BM) mononuclear cells (n = 2). The concentration of cfDNA in IVLBCL was significantly higher than that in diffuse large B-cell lymphoma (DLBCL) (P < .0001) and healthy donors (P = .0053), allowing us to perform WES; most mutations detected in BM tumor DNA were successfully captured in cfDNA and xenograft. IVLBCL showed a high frequency of genetic lesions characteristic of activated B-cell-type DLBCL, with the former showing conspicuously higher frequencies (compared with nodal DLBCL) of mutations in MYD88 (57%), CD79B (67%), SETD1B (57%), and HLA-B (57%). We also found that 8 IVLBCL (38%) harbored rearrangements of programmed cell death 1 ligand 1 and 2 (PD-L1/PD-L2) involving the 3' untranslated region; such rearrangements are implicated in immune evasion via PD-L1/PD-L2 overexpression. Our data demonstrate the utility of cfDNA and imply important roles for immune evasion in IVLBCL pathogenesis and PD-1/PD-L1/PD-L2 blockade in therapeutics for IVLBCL.

Rectal cancer with extensive distal intramural spread treated by abdominoperineal resection.

Distal intramural spread refers to microscopic tumor implantation in the intestinal wall, distal to the inferior edge of a macroscopic tumor but rarely beyond 2 cm. We report a case of rectal cancer with preoperatively diagnosed distant intramural spread to approximately 6.5 cm. A 75-year-old woman diagnosed with upper rectal cancer was scheduled to undergo low anterior resection 5 weeks after initial presentation. However, preoperative digital rectal examination and anoscopy under general anesthesia revealed a rectal tumor 4 cm proximal to the anal verge; adenocarcinoma was diagnosed based on frozen section analysis of the rectal tumor. Therefore, abdominoperineal resection was performed, and histopathological examination confirmed a moderately differentiated adenocarcinoma with distal intramural spread of 6.5 cm. The patient died 18 months postoperatively owing to lung metastasis. Although distal intramural spread is rare and can be difficult to detect prior to surgery, repeated rectal examination, with prompt histological examination of suspicious lesions, can ensure earlier diagnosis to achieve better local control by radical surgery including sufficient distal margin.

Hematogenous intestinal metastases from sigmoid colon cancer presenting as iliopsoas abscess and bowel obstruction.

Intestinal metastases from colorectal cancer typically occur by intraperitoneal spread, whereas those occurring via hematogenous route are exceedingly rare. We report a case of intestinal metastases from sigmoid colon cancer that presented as iliopsoas abscess and ileus. A 78-year-old man who had undergone sigmoidectomy for sigmoid colon cancer 5 years ago was referred to our hospital with recurrent ileus and fever. Abdominal computed tomography showed a left iliopsoas abscess and a mass near the abscess that had ostensibly caused ileus. The patient underwent segmental resection of the jejunum including the mass. Histopathological examination of the resected specimen revealed moderately differentiated adenocarcinoma proliferating mainly in the submucosal and muscular layers, which was pathologically identical to the colon cancer resected 5 years ago. He died 18 months after the surgery because of liver metastases. This case report highlights the delayed occurrence of colorectal metastases at unusual sites, such as the small bowel, more than 5 years after the resection of the primary cancer. Intestinal metastases should be considered in patients with a history of colon cancer, particularly in those with recurrent ileus or abdominal abscess with no obvious cause.

An epilepsy-associated glioneuronal tumor with mixed morphology harboring FGFR1 mutation.

Glioneuronal tumor (GNT) is a rare central nervous system neoplasm composed of glial and neuronal components. Making the specific diagnosis of GNT can be challenging due to histopathological and genetical similarities among some GNTs and low-grade gliomas. We report a case of GNT with rosette-forming glioneuronal tumor, dysembryoplastic neuroepithelial tumor, and pilocytic astrocytoma-like morphology harboring FGFR1 mutation. A 16-year-old female presented with absence seizures. Magnetic resonance imaging revealed a right temporal lobe mass with multinodular enhancement by gadolinium administration. The tumor was mostly composed of oligodendrocyte-like cells (OLCs) with variable perinuclear haloes. Abundant Rosenthal fibers and eosinophilic granular bodies were identified. Neither mitotic figures nor areas of necrosis were seen. Focal neurocytic rosette features, involving ring-like arrays of OLCs around eosinophilic cores, were observed. Direct sequencing showed a missense mutation in FGFR1 K656E, whereas FGFR1 N546K, PIK3CA, and BRAF V600E were intact. KIAA1549-BRAF fusion was not detected by fluorescence in situ hybridization analysis.

Short-term detection of gastric genotoxicity using the DNA double-strand break marker γ-H2AX.

DNA damage caused by Helicobacter pylori infection and chronic inflammation or exposure to genotoxic agents is considered an important risk factor of gastric carcinogenesis. In this study, we have evaluated a short-term technique to detect DNA damage response to various chemical carcinogens; it involves visualization of Ser 139-phosphorylated histone H2AX (γ-H2AX) foci by immunohistochemistry and expression analysis of other genes by quantitative RT-PCR. Six-week-old male rats were intragastrically administered N-methyl-N-nitrosourea (MNU), 3,2'-dimethyl-4-aminobiphenyl (DMAB), dimethylnitrosamine (DMN), and 1,2- dimethylhydrazine (DMH) for 5 days/week for 4 weeks, using corn oil as a vehicle. Animals were sacrificed at day 28, and their stomachs were excised. γ-H2AX foci formation, indicating DNA double-strand breaks, was observed in the proliferative zone of both fundic and pyloric glands. The number of positive cells per gland was significantly high in pyloric glands in the MNU group and in fundic glands in the MNU and DMAB groups. A significant increase in p21waf1 mRNA level was observed in the DMN group compared with the control, which was in contrast to the decreasing tendency of the h2afx mRNA level in the MNU and DMN groups. Apoptotic cells positive for γ-H2AX pan or peripheral nuclear staining were observed on the surface layer of the fundic mucosa in the MNU group. The fundic pepsinogen a5 (pga5) mRNA level showed a significant decrease, indicating gland damage. The pyloric pepsinogen c mRNA level showed no change. In conclusion, γ-H2AX in combination with other gene expression analyses could be a useful biomarker in a short-term experiment on gastric chemical genotoxicity.

Eradication of Helicobacter pylori Induces Immediate Regressive Changes in Early Gastric Adenocarcinomas.

OBJECTIVE: Helicobacter pylori eradication is expected to prevent gastric cancer. However, morphological alterations after eradication often hinder accurate diagnosis. Therefore, we evaluated endoscopic and histological changes in gastric tumors after eradication of H. pylori in a time-dependent manner. METHODS: We classified 144 cases of endoscopic submucosal dissection (ESD) of early gastric cancer into the following categories: (i) patients positive for H. pylori with no eradication history, (ii) patients positive for H. pylori who underwent ESD 2 months after eradication, (iii) patients negative for H. pylori with an eradication history of at least 6 months before ESD, and (iv) patients negative for H. pylori with an unknown history. We compared endoscopic and histological factors between the groups. RESULTS: The characteristics of cancers positive for H. pylori were exploding shape, superficial high-grade atypical epithelium, and a surface proliferating zone. H. pylori eradication induced a series of endoscopic and histological changes, including shape -depression, appearance of surface regenerative and lower-grade atypical epithelium, and a downward shift of the proliferative zone within a period as short as 2 months. CONCLUSION: H. pylori eradication rapidly causes cancer regression and leads to tumor shrinkage, diminished atypism, and shortened proliferative zone, resulting in drastic morphological changes.