A Rare Pancreatic Tumor with Adenomatoid Tumor-like Findings.

A 74-year-old woman was referred to our hospital for the evaluation of slightly elevated tumor marker levels. Computed tomography revealed a well-demarcated tumor, approximately 15 mm in diameter, in the pancreatic tail. Endoscopic ultrasound-guided fine-needle aspiration findings suggested poorly differentiated cancer. The tumor was surgically resected, but postoperative pathologic confirmation was not possible. After one year without treatment and no recurrence, an evaluation by a specialized facility was requested for a definitive diagnosis. Adenomatoid tumor was deemed most likely based on the histopathology and immunostaining findings; however, a definitive diagnosis was difficult because of atypical findings. The patient was recurrence-free for 36 months at the last follow-up.

Two cases of follicular lymphoma with MYC gene abnormalities that presented with bone marrow necrosis.

Bone marrow necrosis (BMN) occurs most frequently in hematological malignancies and sometimes in non-hematological disorders. Lymphoid diseases causing necrosis are regarded as high-grade disease. B-lymphoblastic leukemia/lymphoma is the most common malignant cause of BMN. Here, we present two patients with follicular lymphoma (FL) and MYC gene abnormalities who developed BMN. In one case of BMN, the necrosis disappeared in response to chemotherapy, and the patient survived with complete remission. In the other case, BMN remained even after chemotherapy, and effective chemotherapy could not be administered due to suppressed hematopoiesis, which led to the lymphoma worsening and the patient's death. Indolent lymphomas, such as FL, as in these cases, have the potential to develop BMN. It is important to detect the development of BMN and administer chemotherapy early to improve patient prognosis, since severe BMN prevents patients from receiving effective treatment.

Ghost cell odontogenic carcinoma arising in dentinogenic ghost cell tumor with next-generation sequencing cancer panel analysis: A case report.

OBJECTIVE: Ghost cell odontogenic carcinoma (GCOC) is a rare tumor that can sometimes occur from dentinogenic ghost cell tumor (DGCT). STUDY DESIGN: We report a case of GCOC arising from DGCT that underwent long-term follow-up with multiple biopsies. The biopsy specimens were analyzed using a next-generation sequencing cancer panel. RESULTS: Histopathology of the resected tumor revealed that the boundary between benign and malignant components was clear. In immunohistochemistry, the nuclei of malignant tumor cells were positive for ß-catenin and LEF-1. CTNNBI mutation was detected in all 4 biopsy specimens, and all of these mutations were identical (c.98C>G (p.Ser33Cys)). No other gene mutations that could definitively cause malignant transformation were detected. CONCLUSIONS: This case suggested that GCOC and DGCT are ghost cell neoplasms caused by a common mutation of CTNNB1 and that the malignant cells of GCOC are derived from cells that specifically differentiate into ghost cells.

Granulocyte-colony stimulating factor-producing uterine cervical cancer treated with chemoradiotherapy: A case report with mutation analysis and literature review.

Granulocyte-colony stimulating factor-producing uterine cervical cancer is a rare aggressive disease, which may be genetically distinct from other uterine cervical cancers.

Comparative genome-wide analysis of gastric adenocarcinomas with hyperplastic polyp components.

Gastric hyperplastic polyps are common and generally regarded as benign lesions, whereas gastric adenocarcinomas infrequently occur from gastric hyperplastic polyps. Although gastric hyperplastic polyps have received a lot of attention because of their association with malignant transformation, it remains unclear whether gastric hyperplastic polyps are neoplastic lesions that have sporadic genetic changes similar to colorectal hyperplastic polyps. We performed genome-wide analyses of two gastric adenocarcinomas with hyperplastic polyp components. The interface between "adenocarcinoma" and "hyperplastic polyp" components was fairly sharp, and the adenocarcinoma components had copy number alterations and TP53 mutations, whereas the hyperplastic polyp components had only single nucleotide polymorphisms, which were also found in adenocarcinoma components. We did not detect any somatic changes in the hyperplastic polyp components, even in genome-wide analyses, which was in contrast to the adenocarcinoma components. However, due to the small number of cases examined herein, further genetic analyses of more cases are needed.

Immunophenotypic features of immaturity of neural elements in ovarian teratoma.

Neural components in mature teratomas are common and the general assumption is that they are quite similar to those in the mature central nervous system (CNS). We investigated 44 ovarian teratomas by immunohistochemistry to determine cellular and structural immaturity of neural elements. Most teratomas contained cells differentiating into astrocytes positive for nestin, a neural stem cell marker. These nestin-positive astrocytes generally co-expressed glial fibrillary acidic protein-delta, an immature astrocyte marker. Olig2-positive cells were randomly scattered. Areas comprising cells that differentiated into neurons were positive for NeuN and synaptophysin. The border between white and gray matter was ill-defined and more NeuN-positive cells were distributed in areas that were positive for myelin basic protein, indicating that the distribution of neurons and glial cells was disturbed. Peripheral nerve bundles positive for Schwann/2E, an antigen specific for myelinating Schwann cells, were mixed within CNS-like tissues. These results show that apparently mature teratomas are not in fact mature, at least in terms of neural elements, as they harbor immature cells and structural abnormalities. The neural elements of surgically resected teratomas might represent a premature state of the human CNS, and thus be potentially useful for studies of developmental neurobiology as well as gliomagenesis.

Malignant meningioma with adenocarcinoma-like metaplasia: demonstration of intestinal phenotype.

Meningiomas show a diverse histopathologic appearance, often referred to as metaplastic changes; however, adenocarcinoma-like metaplasia is an extremely rare condition. Here, we present a novel case. A dura-based bulky mass located in the right frontotemporal region was identified radiologically in an 83-year-old woman. The tumor, yellow to ash-gray in color, was subtotally removed. Histopathological examination revealed robust adenocarcinoma-like structures within a conventional meningothelial neoplasm. Meningioma elements showed a WHO grade I to III histology. Morphological and immunophenotypic transition between meningothelial and columnar epithelial cells was confirmed on detailed observation. It was of note that the adenocarcinomatous components shared an immunophenotype with intestinal epithelium, expressing CDX2, MUC2 and cytokeratin 20. The present case could be differentiated from secretory meningioma based on distinct cellular atypia, lack of intracytoplasmic lumina and pseudosammoma bodies, and the intact status of the KLF4 gene. In addition, the morphological and immunophenotypic transition excluded the possibility of metastatic carcinoma within meningioma. This is the first reported case of meningioma with adenocarcinoma-like metaplasia harboring an intestinal immunophenotype.