Mucin distribution in bronchiolar adenoma/ciliated muconodular papillary tumor reveals organoid differentiation simulating the normal lung.

Bronchiolar adenoma/ciliated muconodular papillary tumor is a lung neoplasm exhibiting various degrees of proximal and distal bronchiolar differentiation. Here, we evaluated distribution of MUC5AC and MUC5B in bronchiolar adenoma/ciliated muconodular papillary tumor for comparison with that seen in normal respiratory tract. In normal respiratory tract, MUC5AC was mainly distributed in large bronchi, while MUC5B was distributed in bronchi, bronchioles, and submucosal glands. In bronchiolar adenoma/ciliated muconodular papillary tumor, MUC5AC was primarily distributed in luminal cells of large airspaces, and MUC5B was distributed in luminal cells of small airspaces and mucinous glands, in addition to large airspaces, regardless of distal or proximal differentiation. In particular, MUC5B was distributed in non-mucinous club and ciliated cells in both the normal respiratory tract and bronchiolar adenoma/ciliated muconodular papillary tumor. These results indicate that MUC5AC and MUC5B distribution in bronchiolar adenoma/ciliated muconodular papillary tumor is similar to that seen in normal respiratory tract, suggestive of organoid differentiation simulating the normal lung.

[Inverted Variant of Urothelial Carcinoma of the Urinary Bladder : A Case Report].

A 69-year-old male complained of gross hematuria. Cystoscopy revealed a papillary pedunculated tumor. The tumor was approximately 4 cm in length, and mimicked an inverted papilloma with a small stalk and smooth surface, located on the bladder trigone. Transurethral resection of the bladder tumor was performed, and the tumor was resected en bloc. Histopathological examination revealed thick and irregular epithelial cords. Immunohistochemically, Ki-67 labeling index was 5%, p40 and CK7 were positive, and CK20 was negative. Then, this tumor was diagnosed as inverted variant of urothelial carcinoma. Even when gross appearance is compatible with inverted papilloma, pathological and immunohistochemical examinations are essential for accurate diagnosis of inverted bladder tumor. No recurrence was observed by cystoscopy 13 months after the resection.

Pulmonary adenocarcinoma possibly developed from the cut-end of small-sized adenocarcinoma in the lung periphery as recurrence 13 years after its wedge resection.

BACKGROUND: It is a big topic for general thoracic surgery whether still curability can be obtained by limited resection for peripheral small-sized nodules of non-small cell lung cancer (NSCLC) in the current era of frequent computed tomography (CT) use. Accumulation of information on problematic cases would be meaningful for surgeons to select better surgical procedures. CASE PRESENTATION: A 69-year-old man was pointed out an enlarged 2.1-cm solid nodule on the edge of staple line of the residual right upper lobe by chest CT. He had past history of the lung cancer surgery, wedge resection of the same right upper lobe 13 years ago. The pathological findings were 1.1-cm, p-TlbN0M0, p-stage IA2-adenocarcinoma. Thereafter, he received no adjuvant therapy. This time, the trans-bronchial lung biopsy revealed adenocarcinoma. After the completion lobectomy of the residual right upper lobe, the tumor was diagnosed as adenocarcinoma consistent with recurrence of small-sized adenocarcinoma in the lung periphery developed from the cut-end because of similarities between present and previous tumors on histopathology and p53-positivity. CONCLUSIONS: When limited resection has been performed for small-sized NSCLC presenting solid nodule on thin-slice CT images, long-term postoperative follow-up time will be necessary for monitoring, considering the possibility of cut-end recurrence.

Cloning of Helicobacter suis cholesterol α-glucosyltransferase and production of an antibody capable of detecting it in formalin-fixed, paraffin-embedded gastric tissue sections.

Helicobacter suis (H. suis), formerly called Helicobacter heilmannii type 1 (H. heilmannii), is a gram-negative bacterium of the Helicobacter species. This pathogen infects the stomach of humans and animals such as dogs, cats, pigs, and rodents, the latter giving rise to zoonotic infection. Here, we generated a H. suis-specific antibody useful for immunohistochemistry with formalin-fixed, paraffin-embedded tissue sections. To do so, we began by cloning the gene encoding H. suis cholesterol α-glucosyltransferase (αCgT). αCgT is the key enzyme responsible for biosynthesis of cholesteryl α-D-glucopyranoside (CGL), a major cell wall component of Helicobacter species including H. suis. The deduced amino acid sequence of H. suis αCgT had 56% identity with the corresponding Helicobacter pylori (H. pylori). We then developed a polyclonal antibody (anti-Hh-I205R) by immunizing rabbits with a 205 amino acid H. suis αCgT fragment. Immunohistochemistry with the anti-Hh-I205R antibody could differentiate H. suis from H. pylori in gastric mucosa sections derived from mice infected with either pathogen. We then probed formalin-fixed, paraffin-embedded sections of human gastric mucosa positive for H. suis infection with the anti-Hh-I205R antibody and detected positive staining. These results indicate that anti-Hh-I205R antibody is specific for H. suis αCgT and useful to detect H. suis in gastric specimens routinely analyzed in pathological examinations.

Gastric hepatoid adenocarcinoma resulting in a spontaneous gastric perforation: a case report and review of the literature.

BACKGROUND: Gastric hepatoid adenocarcinoma (GHAC) is an atypical form of gastric cancer (GC) that has similar tissue morphology to hepatocellular carcinoma and frequently produces alpha-fetoprotein. We present an exceedingly rare case of GHAC resulting in a spontaneous gastric perforation. CASE PRESENTATION: A 61-year-old man presented at our institution complaining of abdominal and back pain. A computed tomography scan revealed a spontaneous gastric perforation with a solitary liver tumor and lymph node swelling. Following a diagnosis of advanced-stage GC with a gastric perforation, perforative peritonitis, multiple lymph node metastases, and a solitary metastasis of the lateral segment of the liver, the patient underwent distal gastrectomy. Histopathology of the resected specimen revealed that the tumor cells were arranged in a hepatoid pattern. On immunohistochemical staining, the tumor cells were positive for alpha-fetoprotein and Sal-like protein 4. Thus, the patient was diagnosed with GHAC. Hepatic resection of the solitary liver metastasis was performed. However, recurrence occurred and the patient achieved complete response following tegafur/gimeracil/oteracil-based chemotherapy. CONCLUSIONS: GHAC is a highly malignant histological subtype of GC. We reported on an extremely rare case of GHAC resulting in a spontaneous gastric perforation and reviewed the literature, including epidemiological data, treatment regimens, and the association between GHAC and alpha-fetoprotein-producing GC.