We have characterized a strain of double transgenic mice with simian virus 40 large tumor antigen and prokaryotic lacZ under the control of the myelin basic protein promoter that develops spindle-cell sarcomas and osteogenic sarcomas at 5-7 months of age. Although poorly differentiated, the spindle-cell sarcomas were characterized as malignant Schwannomas based on their neural association, the ...

Non-small cell lung cancer (NSCLC) is notorious for its paltry responses to first-line therapeutic regimens. In contrast to acquired chemoresistance, little is known about the molecular underpinnings of the intrinsic resistance of chemo-naïve NSCLC. Here we report that intrinsic resistance to paclitaxel in NSCLC occurs at a cell-autonomous level because of the uncoupling of mitotic defects from...

Ovarian sex cord-stromal tumors are relatively infrequent neoplasms that account for approximately 8% of all primary ovarian neoplasm. Sex cord-stromal tumors of the ovary include granulosa cell tumors, fibrothecomas, Sertoli-Leydigcell tumors, steroid cell tumors, and sclerosing stromal tumors (SST). Sclerosing stromal tumors account for 2% to 6% of ovarian stromal tumors. Despite the rarity o...

PIK3CA, which codes for the p110α catalytic subunit of phosphatidylinositol 3-kinase, is one of the most frequently mutated genes in human breast cancer. Here, we describe a mouse model for PIK3CA-induced breast cancer by using the ROSA26 (R26) knock-in system, in which targeted Pik3ca alleles can be activated through transgenic expression of Cre recombinase. We mated Pik3ca(H1047R) and Pik3ca(...

An inflammatory myofibroblastic tumor (IMT) is a distinctive neoplasm composed of myofibroblastic and fibroblastic spindle cells, accompanied by inflammatory infiltration of plasma cells, lymphocytes, and eosinophils. IMTs rarely occur in the urinary bladder. It is important to distinguish this tumor from other malignant spindle cell tumors. Herein, we report a patient with an IMT showing muscl...

The sarcomatoid variant of hepatocellular carcinoma (HCC) is a rare histologic variant comprising malignant spindle cells and typical HCC. The proportion of the spindle cell component varies; when the tumor fully consists of malignant spindle cells, it is difficult to distinguish from various primary sarcomas. The 2010 World Health Organization classification of gastrointestinal tract tumors cl...

Spindle cell carcinoma (SpCC) is referred to as a variant of oral squamous cell carcinoma. It is also known as "sarcomatoid squamous cell carcinoma" because it consists of normal squamous carcinoma cells with spindle-shaped cells that appear similar to a sarcoma. The term, "second primary tumor" (SPT) or "double primary tumor", is proposed for a second tumor that develops independently from the...

Background: Gastrointestinal stromal tumors (GISTs) constitute the majority of gastrointestinal mesenchymal tumors. They usually express a proto-oncogen protein called CD117 detected by immunohistochemistry. This study investigated the differentiation of GISTs as well as the risk of aggressive behaviors in GISTs from surgically-treated patients in university affiliated hospitals. Methods: The c...

Ovarian cystic tumors with a mural nodule are a rare entity. We report a case of a mural nodule of anaplastic spindle cell carcinoma in an ovarian mucinous cystic tumor of borderline malignancy. The patient was a 45-years-old Japanese woman who presented with an ovarian cyst. She suffered from mature cystic teratoma of both ovaries 9 years before the present history. Image analysis and laborato...