A symptomatic intercalated duct lesion of the parotid gland: a case report with immunohistochemical and genetic analyses.

Intercalated duct lesions (IDLs) are usually asymptomatic. We report a case of IDL, in which a palpable mass formed. The patient was a 45-year-old Japanese male, who noticed a mass in the left parotid region. The nodular lesion was well-circumscribed, but did not have a fibrous capsule or exhibit infiltrative growth. It contained a small cystic space and consisted of basaloid cells arranged in a cribriform pattern and inner ductal cells. It had some solid areas of nest-like proliferation displaying mild cellular atypia. Immunohistochemically, the luminal cells were positive for cytokeratin (CK)7 and epithelial membrane antigen, and the abluminal cells were positive for CK5/6, p63, and DOG1. S-100 protein-positive stromal cells were also seen. The lesion's cells were all positive for SOX10, and the nuclei of some basaloid cells were positive for ß-catenin. The Ki-67 labeling index was 3.8%. The ductal cells contained diastase-digestion-resistant, Periodic acid Schiff-positive zymogen granules. Genetically, the lesion harbored a missense mutation in the CTNNB1 gene. We diagnosed the lesion as an IDL. As IDLs are usually small non-neoplastic lesions, symptomatic cases are rare. Based on its common immunohistochemical and genetic features, IDL may be a precursor of basal cell adenoma/adenocarcinoma, such as intercalated duct adenoma.

An unusual presentation of chordoma as a pyloric ring submucosal tumor: The first case report of a primary gastrointestinal lesion in humans.

INTRODUCTION AND IMPORTANCE: Chordomas are rare malignant bone neoplasms that are presumed to arise from chordal remnants in the fetal stage and typically occur along the axial skeleton. The extra-skeletal chordomas reported to date include soft tissue of the extremities and nasopharynx. Chordoma arising from the gastrointestinal wall has not been previously described. CASE PRESENTATION: We report on a 42-year-old man with primary chordoma presenting as a gastroduodenal submucosal tumor centered on the pyloric ring. The patient was consistently asymptomatic, and the tumor was an incidental finding. However, during a follow-up at approximately 1.6 years, an increase in tumor size was identified on computed tomography (CT), and surgical resection was performed without a definite pathologic diagnosis. The patient was successfully treated with distal gastrectomy, and the histological diagnosis was a conventional chordoma. The diagnosis was confirmed via immunohistochemical staining for brachyury, pan-cytokeratin, S-100, and SOX9. Postoperative CT and magnetic resonance imaging revealed no recurrence or metastasis during the 1.5-year follow-up period. CLINICAL DISCUSSION: Primary chordomas of the digestive tract are rare. Embryologic development of the notochord does not explain the existence of remnants in the gastrointestinal wall. Moreover, notochordal remnants, as precursors of chordoma, were not identified in the current case. The gastroduodenal chordoma may not have originated from embryonic notochordal remnants but through aberrant brachyury activation without a notochordal precursor. CONCLUSION: We report the first case of primary gastrointestinal chordoma in humans. The tumor was completely removed surgically, without postoperative recurrence.

Hybrid Carcinoma of the Parotid Gland: An Extremely Rare Three Cases with an Immunohistochemical Analysis and a Review of the Literature.

Salivary hybrid carcinoma (HC) is defined as when two or more kinds of carcinoma exist at the same location in a single mass. We reestimated and examined three cases of salivary gland HC. Case 1 involved a 76-year-old male. Case 2 involved a 74-year-old female. Case 3 involved a 66-year-old male. Histologically, case 1 involved a combination of salivary duct carcinoma (SDC) and squamous cell carcinoma (SqCC). Immunohistochemically, the former was positive for gross cystic disease fluid protein (GCDFP)-15 and androgen receptor (AR). Case 2 involved a combination of SqCC and neuroendocrine carcinoma. Immunohistochemically the latter was positive for synaptophysin and neural cell adhesion molecule (NCAM). Case 3 involved a combination of SDC and epithelial-myoepithelial carcinoma (EMC). Immunohistochemically, the former was positive for GCDFP-15 and AR, whereas the inner cells of the latter were positive for cytokeratin 7, and the outer cells of the latter were positive for actin. Because of the transitional zone between SDC and EMC, it was speculated that high-grade SDC arose from low-grade EMC.

Periostin expression and its supposed roles in benign and malignant thyroid nodules: an immunohistochemical study of 105 cases.

BACKGROUND: Thyroid tumors are often difficult to histopathologically diagnose, particularly follicular adenoma (FA) and follicular carcinoma (FC). Papillary carcinoma (PAC) has several histological subtypes. Periostin (PON), which is a non-collagenous extracellular matrix molecule, has been implicated in tumor invasiveness. We herein aimed to elucidate the expression status and localization of PON in thyroid tumors. METHOD: We collected 105 cases of thyroid nodules, which included cases of adenomatous goiter, FA, microcarcinoma (MIC), PAC, FC, poorly differentiated carcinoma (PDCa), and undifferentiated carcinoma (UCa), and immunohistochemically examined the PON expression patterns of these lesions. RESULTS: Stromal PON deposition was detected in PAC and MIC, particularly in the solid/sclerosing subtype, whereas FA and FC showed weak deposition on the fibrous capsule. However, the invasive and/or extracapsular regions of microinvasive FC showed quite strong PON expression. Except for it, we could not find any significant histopathological differences between FA and FC. There were no other significant histopathological differences between FA and FC. Although PDCa showed a similar PON expression pattern to PAC, UCa exhibited stromal PON deposition in its invasive portions and cytoplasmic expression in its carcinoma cells. Although there was only one case of UCa, it showed strong PON immunopositivity. PAC and MIC showed similar patterns of stromal PON deposition, particularly at the invasive front. CONCLUSIONS: PON may play a role in the invasion of thyroid carcinomas, particularly PAC and UCa, whereas it may act as a barrier to the growth of tumor cells in FA and minimally invasive FC.

A rare case of high-grade intraductal carcinoma of the upper lip: immunohistochemical and genetic analyses.

Although intraductal carcinoma (IDC) of the salivary glands was previously called low-grade cribriform cystadenocarcinoma, it was newly categorized in the 4th version of the World Health Organization classification. We report a case of IDC of the upper lip and examined it immunohistochemically and genetically. The patient was a 48-year-old Japanese female, who noticed a tiny nodule on her left upper lip. Histologically, the tumor cells, which had eosinophilic cytoplasm, exhibited papillary and solid growth patterns, and regions of suspected microinvasion or intraductal spread were also seen at the periphery of the tumor. Small necrotic foci were noted. Immunohistochemically, the tumor cells were diffusely positive for the androgen receptor, CK19, CK5/6, EGFR, and SOX10, whereas they were focally positive for GCDFP-15, S-100 protein, and mammaglobin. The tumor nests were surrounded by alpha-smooth muscle actin-p63-/calponin-/CK14-positive myoepithelial cells. The Ki-67 labeling index was 51.2%. Genetic analysis showed no evidence of the TRIM27-RET or NCOA4-RET fusion gene. We finally diagnosed the tumor as a high-grade mixed intercalated duct/apocrine-type IDC of the upper lip. IDC of the minor salivary glands is exceedingly rare. We discuss diagnostic problems associated with minor salivary gland lesions, and the "basal-like" phenotype of this case.

Basaloid squamous cell carcinoma with adenoid cystic-like features of the head and neck region: A report of two cases.

The histology of basaloid squamous cell carcinoma (BSCC) can resemble that of adenoid cystic carcinoma (AdCC). Herein, we report two cases of BSCC with adenoid cystic-like features (BSCC-AdC). We collected cases of AdCC and BSCC of the head and neck region, extracted two cases with unusual histology, and reexamined them histologically and immunohistochemically. Case 1 involved an 81-year-old Japanese male, who had an elastic-hard mass on the left side of his tongue, and a biopsy examination suggested AdCC. Case 2 involved a 63-year-old Japanese male, who had a polypoid mass on his right hypopharynx. He was diagnosed with AdCC with high-grade transformation. Histologically, atypical cells in a myxoid stroma, which exhibited trabecular, nest-like, and/or cribriform growth patterns, and necrosis were observed in both cases. Case 2 displayed more marked cellular atypia than Case 1. Immunohistochemically, the tumor cells were diffusely positive for cytokeratin 5/6, p63/p40, SRY-related HMG-box 10 and Ki-67, but negative for other myoepithelial markers and p16. Finally, both cases were rediagnosed as BSCC-AdC. It is known that esophageal BSCC displays adenoid cystic-like features, and BSCC-AdC also sometimes occurs in the head and neck region. Clinicians should carefully differentiate BSCC-AdC from AdCC of the minor salivary glands and human papillomavirus-related carcinoma.

Characteristics of health problems in returned overseas travelers at a tertiary teaching hospital in a suburban area in Japan.

Few studies have analyzed the characteristics of patients who develop physical disorders after overseas travel. We retrospectively reviewed the medical records of 183 patients who visited Nara Medical University Hospital from 2008 to 2016 because of physical problems after traveling abroad. The main travel destinations were Southeast Asia (n = 100), Africa (n = 27), and South Asia (n = 23). The main reasons for the travel were leisure (n = 96), business (n = 51), and volunteer work (n = 19). The most common final diagnosis was gastrointestinal disease (n = 72), followed by febrile disease (n = 59) and respiratory disease (n = 19). There were eight malaria cases, including one patient who was infected after <14 days of overseas travel. Additionally, 61 of 71 cases of travelers' diarrhea and 15 of 21 cases of dengue fever occurred after <14 days travel. 26 cases of vaccine preventable diseases, such as hepatitis A, typhoid fever, and influenza, were observed. Consequently, healthcare providers should notify Japanese overseas travelers that there is a non-negligible health risk inherent to short-term travel, while stressing on the importance of pre-travel medical consultation.

Acceleration of discrete stochastic biochemical simulation using GPGPU.

For systems made up of a small number of molecules, such as a biochemical network in a single cell, a simulation requires a stochastic approach, instead of a deterministic approach. The stochastic simulation algorithm (SSA) simulates the stochastic behavior of a spatially homogeneous system. Since stochastic approaches produce different results each time they are used, multiple runs are required in order to obtain statistical results; this results in a large computational cost. We have implemented a parallel method for using SSA to simulate a stochastic model; the method uses a graphics processing unit (GPU), which enables multiple realizations at the same time, and thus reduces the computational time and cost. During the simulation, for the purpose of analysis, each time course is recorded at each time step. A straightforward implementation of this method on a GPU is about 16 times faster than a sequential simulation on a CPU with hybrid parallelization; each of the multiple simulations is run simultaneously, and the computational tasks within each simulation are parallelized. We also implemented an improvement to the memory access and reduced the memory footprint, in order to optimize the computations on the GPU. We also implemented an asynchronous data transfer scheme to accelerate the time course recording function. To analyze the acceleration of our implementation on various sizes of model, we performed SSA simulations on different model sizes and compared these computation times to those for sequential simulations with a CPU. When used with the improved time course recording function, our method was shown to accelerate the SSA simulation by a factor of up to 130.

Somatostatinoma of the papilla of Vater with multiple gastrointestinal stromal tumors in a patient with von Recklinghausen's disease.

We report a case of somatostatinoma of the papilla of Vater with multiple gastrointestinal stromal tumors in a patient with von Recklinghausen's disease (VRD). A 64-year-old woman who had had recurrent attacks of acute pancreatitis and cholangitis was found, on gastroduodenal endoscopy, to have a tumor of the papilla of Vater and multiple submucosal tumors of the stomach and duodenum. Numerous submucosal tumors were observed in the stomach, duodenum, and jejunum, and total excision of the papilla of Vater and resection of the duodenal and jejunal submucosal tumors was performed. The tumor of the papilla of Vater showed the histologic appearance of a dense proliferation of tumor cells in acinar form, from the duodenal mucosa to the muscle layer, and psammoma bodies were revealed within the tumor. Immunohistologically, the tumor cells were intensely positive for somatostatin. The submucosal tumors of the duodenum and jejunum were negative for smooth muscle actin, s-100, and neuron-specific enolase (NSE), and positive for CD34 and c-kit, and they were diagnosed as gastrointestinal stromal tumors (GISTs) according to the strict definition. The only 25 cases of papilla of Vater somatostatinoma associated with VRD to have been reported in the English-language literature since 1982 are reviewed, as well as our own case.