Visceral Mast Cell Tumour Research Articles

Retraction Note to: Diagnostic procedures for improving of the KIT (CD117) expressed allele burden for the liver metastases from uterus mast cell tumors: prognostic value of the metastatic pattern and tumor biology.

The activating KIT marker plays a central role in the pathogenesis, diagnosis, and targeted treatment of systemic mastocytosis (SM). Recent studies have identified the KIT (CD117) as a marker that distinguishes nonneoplastic from neoplastic mast cells in human systemic mastocytosis. In this study, we conclude that immunohistopathology assays for KIT staining pattern are useful complimentary tools for diagnosis and evaluation of prognosis in uterus mast cell tumor (MCT) metastasis to the liver in 10 patients. Uterine and hepatic cytology revealed mast cell neoplasia, which was confirmed as visceral mast cell tumor on postmortem examination. Histological changes of densely packed, poorly differentiated neoplastic mast cells, sheets of neoplastic round to pleomorphic cells that formed nonencapsulated nodules, high mitotic figures, necrosis, and fibrosis were found. In addition, eosinophils were scattered among the mast cells at the periphery of the nodules. These findings indicate tumors of high-grade malignancy with infiltrative cells resembling the uterus MCT in the intraparenchymal and periparenchymal areas of the liver. Immunohistochemically, tumors were positive for KIT. The histopathologic features coupled with the KIT immunoreactivity led to diagnosis of high-grade uterus MCTs. Taken together, these findings suggest that CD117 may play a critical role in early uterus MCT development and may be a stimulatory factor in grade 3 MCT. Therefore, the result has supported our hypothesis that there was an increased opportunity to observe a higher CD117 staining pattern in high-grade MCTs.

Diagnostic procedures for improving of the KIT (CD117) expressed allele burden for the liver metastases from uterus mast cell tumors: prognostic value of the metastatic pattern and tumor biology.

The activating KIT marker plays a central role in the pathogenesis, diagnosis, and targeted treatment of systemic mastocytosis (SM). Recent studies have identified the KIT (CD117) as a marker that distinguishes nonneoplastic from neoplastic mast cells in human systemic mastocytosis. In this study, we conclude that immunohistopathology assays for KIT staining pattern are useful complimentary tools for diagnosis and evaluation of prognosis in uterus mast cell tumor (MCT) metastasis to the liver in 10 patients. Uterine and hepatic cytology revealed mast cell neoplasia, which was confirmed as visceral mast cell tumor on postmortem examination. Histological changes of densely packed, poorly differentiated neoplastic mast cells, sheets of neoplastic round to pleomorphic cells that formed nonencapsulated nodules, high mitotic figures, necrosis, and fibrosis were found. In addition, eosinophils were scattered among the mast cells at the periphery of the nodules. These findings indicate tumors of high-grade malignancy with infiltrative cells resembling the uterus MCT in the intraparenchymal and periparenchymal areas of the liver. Immunohistochemically, tumors were positive for KIT. The histopathologic features coupled with the KIT immunoreactivity led to diagnosis of high-grade uterus MCTs. Taken together, these findings suggest that CD117 may play a critical role in early uterus MCT development and may be a stimulatory factor in grade 3 MCT. Therefore, the result has supported our hypothesis that there was an increased opportunity to observe a higher CD117 staining pattern in high-grade MCTs.

Loeffler's Endocarditis and Bicavity Eosinophilic Effusions in a Dog with Visceral Mast Cell Tumour and Hypereosinophilia

A 9-year-old crossbred dog was presented with a 2-week history of diarrhoea and tachypnoea. Marked circulating eosinophilia was identified. Pleural and abdominal effusions were detected by radiography and ultrasonography and cytological examination of these fluids revealed a predominance of eosinophils. Splenic and hepatic cytology revealed mast cell neoplasia, which was confirmed as visceral mast cell tumour on post-mortem examination. Histological changes of myocardial inflammation, necrosis and fibrosis were found. These findings are consistent with Loeffler's endocarditis.

MASTOCYTEMIA ASSOCIATED WITH A VISCERAL MAST CELL TUMOR IN A SUMATRAN TIGER (PANTHERA TIGRIS)

A 6-yr-old male Sumatran tiger (Panthera tigris) with no significant past clinical history was anesthetized for clinical examination after 5 days of lethargy. Clinically, the animal presented with anorexia, pale mucous membranes, and icterus. Hematologic results indicated moderate anemia and severe thrombocytopenia and showed a circulating population of atypical mast cells. The tiger died during anesthesia. On postmortem examination, abdominal hemorrhage associated with marked diffuse hepato-splenomegaly and mesenteric, hepatic, and splenic lymph node hypertrophy were observed. A visceral mast cell tumor was confirmed by histologic examination and toluidine blue staining, with splenic, hepatic, lymphoid, renal, and pulmonary infiltration. Hematologic, postmortem, and histologic findings were consistent with mastocytemia associated with the splenic form of mast cell tumor described in domestic cats.

Visceral Mast Cell Tumour with Hepatocellular Emperipolesis in a Yorkshire Terrier

Visceral Mast Cell Tumour with Hepatocellular Emperipolesis in a Yorkshire Terrier

Aberrant autophosphorylation of c-Kit receptor in canine mast cell tumor cell lines

Several studies indicated that KIT mutation could cause ligand-independent activation of c-Kit receptor in canine mast cell tumor (MCT). The objective of this study was to investigate mechanisms of c-Kit receptor activation in various canine MCT cell lines. Four cell lines, HRMC (derived from cutaneous MCT), VIMC1 (visceral MCT), CoMS1 (visceral MCT) and CMMC1 (cutaneous MCT), were cultured in stem cell factor (SCF, a ligand of c-Kit receptor)-free medium and subjected to analyses of KIT mutation, c-Kit receptor phosphorylation, SCF expression and the effects of SCF stimulation. In addition, the SCF/c-Kit receptor autocrine mechanism was verified in HRMC cells. HRMC cells expressed wild type c-Kit receptor. Both VIMC1 and CoMS1 cells had the same one amino acid (AA) substitution in the extracellular domain of c-Kit receptor. CMMC1 cells had at least three variants of c-Kit receptor such as one AA deletion in the extracellular domain (variant A), one AA substitution in the extracellular domain as well as an internal tandem duplication in the juxtamembrane domain (variant B), and a nonsense mutation (variant C). Both mature and immature forms of c-Kit receptor were observed and the c-Kit receptors were phosphorylated in all cell lines. While both mature and immature forms of c-Kit receptor were substantially phosphorylated in CMMC1 cells, the immature form was slightly phosphorylated in other cell lines. Phosphorylation of c-Kit receptor in HRMC, VIMC1 and CoMS1 cells were enhanced by SCF stimulation whereas no enhancement was observed in CMMC1 cells. There was no effect of SCF stimulation on proliferation of all the cell lines. SCF protein was detectable in only HRMC cells although mRNA expression of SCF was detected in all the cell lines. A tyrosine kinase inhibitor Dasatinib (internal inhibitor) inhibited c-Kit receptor phosphorylation in HRMC cells whereas anti-canine SCF antibody (external inhibitor) had no inhibitory effect. Thus there could be no external SCF/c-Kit receptor autocrine mechanism whereas there could be an internal autocrine mechanism within HRMC cells. The results indicated that consistent c-Kit receptor phosphorylation could be caused by the stimulation with autocrine SCF in HRMC cells while it could be caused by functional mutations of KIT in VIMC1, CoMS1 and CMMC1 cells. As the four canine MCT cell lines had various aberrations associated with c-Kit receptor phosphorylation, KIT mutation and SCF expression, such molecular biological diversity might reflect the different biological behavior in canine MCT.

Visceral mast cell tumour in a dog with haemabdomen and mastocytaemia

Visceral mast cell tumour in a dog with haemabdomen and mastocytaemia

Lomustine for the treatment of gastrointestinal mast cell tumour in a dog

An eight-year-old, male boxer dog was referred for the treatment of a large (5.5 x 5 cm), unresectable visceral mast cell tumour. The dog had a surgical resection performed one month before referral, and it had widespread metastases to the abdominal lymph nodes. The patient was treated with lomustine and prednisone and showed a rapid improvement and increased level of activity, weight gain and consistent tumour reduction. The patient remained in partial remission (defined as a greater than 50 per cent reduction in tumour volume) for seven months. Toxicity was acceptable and was limited to moderate anaemia and two episodes of neutropenia. At the completion of the seven months of therapy, the dog experienced a chemotherapy-induced sepsis, and the owners elected for euthanasia due to financial concerns. At that time, the tumour was still in partial remission. This case report suggests that a combination of lomustine and prednisone is an effective protocol for the palliation of aggressive visceral mast cell tumours.

Visceral mast cell tumour with eosinophilia and eosinophilic peritoneal and pleural effusions in a cat

A cat with weight loss, pyrexia and recurrent lethargy and depression was found to have pleural and peritoneal eosinophilic effusions, peripheral eosinophilia, eosinophilic lymphadenitis and a massively enlarged mesenteric lymph node. Visceral mast cell neoplasia was diagnosed after histopathological examination of a biopsy of the mass. Palliative chemotherapy was attempted unsuccessfully and the cat was euthanased.