A Novel Malignant Peritoneal Mesothelioma with STRN Exon 2 and ALK Exon 20: A Case Report and Literature Review.

Recently, several malignant peritoneal mesotheliomas (MPMs), occurring in young women without asbestos exposure and with fusion genes such as anaplastic lymphoma kinase (ALK) and Ewing sarcoma breakpoint region 1, have been reported. In the present case, we encountered MPM with STRN-ALK fusion in a 17-year-old female adolescent. The case did not respond to chemotherapy and is currently in a clinical trial of alectinib. This is the fourth reported case of MPM with STRN-ALK fusion. Of the 45 cancer cases with STRN-ALK fusion in which the fusion partners were examined, all cases except for the current case showed fusion of exon 3 of STRN and exon 20 of ALK. This is the first case with fusion of exon 2 of STRN and exon 20 of ALK. Further advances in cancer genomic medicine may help clarify the clinical significance of this new fusion. KEY POINTS: Malignant peritoneal mesotheliomas (MPMs) can occur in young women without asbestos exposure and show fusion genes that activate anaplastic lymphoma kinase (ALK) by gene rearrangement. ALK rearrangement and the fusion partner can be detected by companion diagnostics and by next generation sequencing. Patients with MPMs with ALK rearrangement may benefit from target therapy.

Detection of Anaplastic Lymphoma Kinase-Rearranged Mesothelioma Cells in Ascites by Companion Diagnostics.

BACKGROUND: A case of peritoneal mesothelioma with an anaplastic lymphoma kinase (ALK) translocation was identified, and we conducted further studies to obtain diagnostic and therapeutic insights. We believe that this is the first report describing the cytology of this new tumor type. CASE: A teenage woman was referred for severe pleural effusion. Enhanced computed tomography indicated an abdominal mass with ascites. Laparoscopy revealed tumor dissemination from the pelvis to the upper abdomen. Because a high-grade serous carcinoma was suspected, ascitic cytology and biopsy were performed. Cytologically, the tumor displayed characteristics of both adenocarcinoma and reactive or neoplastic mesothelial cells. After extensive pathological evaluation, the tumor was diagnosed as malignant peritoneal mesothelioma. To verify the diagnosis and aid in developing a therapeutic strategy, several companion diagnostics were tried. Surprisingly, the tumor was ALK-positive, and ALK recombination was confirmed by an ALK break-apart test. Retrospectively, cells and tissue specimens were stained with ALK intercalated antibody-enhanced polymer. Tumor cells were clearly distinguished from the nonneoplastic background. Recombination in ALK was reconfirmed by the National Cancer Center Japan, and the patient was enrolled in a clinical trial for alectinib. CONCLUSION: Companion diagnostics-based cytology may provide a useful means of monitoring and evaluating a molecular-targeted therapy.

Colon stenosis due to acute neonatal appendicitis in a preterm baby: a case report.

BACKGROUND: Colon stenosis and acute appendicitis are rare diseases among premature babies. To the best of our knowledge, no study has identified both the conditions in preterm babies. CASE PRESENTATION: Here we report a case of a preterm Japanese male baby who developed ascending colon stenosis and appendicitis. During his neonatal intensive care unit stay, he developed increasing apnea and vomiting with rapidly worsening abdominal distention. Contrast radiographs indicated colon stenosis. Emergent exploratory laparotomy revealed ascending colon stenosis with appendix adhesion; both the lesions were surgically resected. The pathological findings suggested that he had appendicitis several weeks prior to the surgery; the onset of colon lesion seemed later than that of appendix. The perforated appendix was covered by the ascending colon, and inflammatory reactions led to the narrowing of the intestinal lumen. CONCLUSIONS: Neonatal appendicitis and colon stenosis are both challenging for the diagnosis, and early laparotomy is necessary when these conditions are suspected.

A ganglion-rich gastrointestinal stromal tumor: A case report.

We report a case of an extremely rare type of duodenal gastrointestinal stromal tumor (GIST) that included neuronal components. Although gastrointestinal autonomic nerve tumors (GANTs), a subtype of GISTs, exhibit ultrastructural features of the nerve plexus, neuronal cells have not been observed within GANTs or GISTs. GISTs originate from interstitial cells of Cajal (ICCs), which are markedly different from the progenitor cells of neural elements and neural-crest-derived stem cells. This may explain why GISTs typically lack neuronal elements. It remains unclear that the neuronal components of this tumor are neoplastic or hyperplastic, but proliferation and survival of ICCs have recently been reported to be closely related to neurons. Although we could not find the KIT, PDGFR, and BRAF mutation as far as we examined, it may have had a rare mutation in NF1, a fusion of EVT6-NTRK3, or an as-yet-unknown KIT mutation that affected neurogenesis. Further investigation of related genetic mutations and accumulation of data from other similar cases is needed.

[A Case of Secondary Extramammary Paget's Disease Aroundthe Cutaneous Stoma after Radical Cystectomy].

We present a case of secondary extramammary Paget's disease around the cutaneous ureterostomy stoma after radical cystectomy. An 85-year-old man with bacillus calmette-guérin refractory high-grade urothelial carcinoma underwent radical cystectomy and cutaneous ureterostomy construction. After right ureter cancer diagnosis, he underwent right nephroureterectomy 3 years after the cystectomy. He developed refractory dermatitis around the cutaneous stoma 1 year after the nephroureterectomy. Skin biopsy revealed secondary extramammary Paget's disease, cured by skin excision around the cutaneous stoma and skin grafting. Multiple urothelial carcinoma metastases were detected 6 months later ; he died of urothelial cancer 1 month later.

[Metastatic Atypical Meningioma of the Lung;Report of a Case].

A 56-years-old woman, who had undergone a complete resection for atypical meningioma (grade 2 of World Health Organization classification)8 years before was admitted to our hospital to treat a mass on the right middle lobe detected by chest X-ray. The mass was resected successfully by video-assisted thoracoscopic surgery and pathological diagnosis of the tumor was a metastatic atypical meningioma. We experienced a rare case of extracranial pulmonary metastasis of meningioma. Grade 2 meningioma is thought to have malignant potential of local recurrence and extracranial metastasis compared to grade 1 meningioma, so long-term observation may be necessary after resection of atypical meningioma.

Primary uterine diffuse large B-cell lymphoma (DLBCL) in a patient with prolonged insertion of intrauterine device (IUD).

A 49-year-old female from China was referred to our hospital after endocervical polypectomy. Twenty years before admission, after the birth of her first child, an intrauterine device (IUD) had been inserted due to the one-child policy in China. She had noticed abnormal vaginal bleeding with a foul smell 3 years before admission. Then the IUD was removed and a polyp was found at the IUD contact site. Two months before admission, endocervical polypectomy was performed. Lymphoma was suspected by histological examination and she was referred to our hospital. Further examination confirmed the diagnosis of primary uterine diffuse large B-cell lymphoma (DLBCL). Subsequently, a combination of three cycles of R-CHOP regimen and involved-field radiation therapy was performed, followed by maintenance therapy with five cycles of rituximab. She has remained in complete remission for over 1 year. This case suggests that chronic inflammation induced by prolonged IUD insertion may contribute to the development of primary uterine lymphoma. To the best of our knowledge, this is the first reported case of DLBCL associated with prolonged IUD insertion.

[Metastatic Ovarian Granulosa Cell Tumor of the Diaphragm Resected by Video-assisted Thoracoscopic Surgery;Report of a Case].

A 75-years-old woman, who had undergone a total abdominal hysterectomy and bilateral salpingo-oophorectomy for ovarian granulosa cell tumor( OGCT) 6 years ago, was admitted to our hospital to treat a mass on the right diaphragm detected by computed tomography. The mass was resected successfully by video-assisted thoracoscopic surgery and pathological diagnosis of the tumor was a metastatic OGCT of the diaphragm. To our knowledge, this is the 3rd case report of metastatic OGCT of the diaphragm.

Adenocarcinoma in an intrapancreatic accessory spleen: report of a case.

We report a case of adenocarcinoma in an intrapancreatic accessory spleen (IPAS). A 78-year-old woman presented with abdominal discomfort, and investigations revealed an elevated serum carbohydrate antigen 19-9 level, to 161.8 U/ml (normal, <37 U/ml). Ultrasonography showed a heterogeneous echogenic tumor with a vascular hilum. Computed tomography showed a heterogeneously enhanced tumor, 8 cm in diameter, adjacent to the pancreatic body, accompanying a feeding artery arising from the splenic artery, and a drainage vein flowing into the splenic vein. We performed a distal pancreaticosplenectomy. The tumor was surrounded by a fibrous capsule and was in contact with the pancreatic body. Histological examinations revealed invasive growth of adenocarcinoma in a structure identical to the spleen. The results of both radiological and histological examinations suggested that the tumor originated from an intrapancreatic accessory spleen. Extensive examinations revealed no other malignancy, based on which we concluded that the adenocarcinoma was primary. Surgical intervention is strongly recommended when a malignancy in an IPAS cannot be ruled out.

Comparative histopathological studies in the early stages of acute pathogenic and nonpathogenic SHIV-infected lymphoid organs.

To clarify the early pathological events in simian and human immunodeficiency chimeric virus (SHIV)-infected lymphoid organs, we examined rhesus macaques infected with an acute pathogenic SHIV (SHIV89.6P) or a nonpathogenic SHIV (NM-3rN) by sequential biopsies and serial necropsies. In the SHIV89.6P-infected monkeys, acute thymic involution as shown by increased cortical tingible-body macrophages and by neutrophilic infiltrates without follicular aggregation in the medulla began within 14 days postinoculation (dpi). Cells that were strongly positive for the virus were identified in the thymic medulla. SHIV89.6P-infected lymph nodes showed severe paracortical lymphadenitis with scattered virus-positive cells at 14 dpi and they developed paracortical depletion without the obvious follicular involution. In contrast, NM-3rN-infected monkeys showed no signs of thymic dysinvolution and the lymph nodes exhibited only follicular hyperplasia. NM-3rN-infected monkeys showed much fewer virus-positive cells in these lymphoid tissues than did SHIV89.6P-infected monkeys during the same period. These differences clearly reflect the difference in the virulence of these SHIVs.