Colonic malignant peripheral nerve sheath tumour in a cat

Abstract

Case summary A 14-year-old male neutered domestic mediumhair cat presented with a 4 month history of inappetence and weight loss. Pertinent abnormalities on haematology and biochemistry included a mild microcytic regenerative anaemia (packed cell volume [PCV] 24% [reference interval (RI) 30–45%], mean cell volume 30.8 fl [RI 40–45 fl], absolute reticulocyte count 326.8 × 10 12 ) and increased alkaline phosphatase activity (76 IU/l; RI <50 IU/l). Abdominal ultrasound and CT scan revealed masses in the transverse colon (2.0 cm × 1.2 cm) and right medial liver lobe (5.0 cm diameter). Thoracic radiographs were unremarkable. Right medial liver lobe resection and colectomy were performed. Immunohistochemistry was positive for S-100 protein, vimentin and glial fibrillary acidic protein, very weakly positive for c-kit and negative for muscle-specific actin and CD18, consistent with a colonic malignant peripheral nerve sheath tumour (MPNST) with a hepatic metastasis. Postoperative treatment with metronomic cyclophosphamide was well tolerated. Eighteen months postoperatively the cat re-presented after 3 days of progressive lethargy and inappetence. Haematology revealed a marked non- or pre-regenerative anaemia (PCV 10%). Coagulation times were prolonged (prothrombin time 39 s [RI 15–22 s] and activated partial thromboplastin time >300 s [RI 65–119 s]). Abdominal ultrasound identified multiple renal and hepatic nodules. Euthanasia was performed and post-mortem examination confirmed metastasis of the MPNST. Relevance and novel information This report describes the treatment of a metastatic colonic peripheral nerve sheath tumour in a cat. Feline visceral MPNSTs are rare and little is known about prognosis or optimal treatment.

A Scoping Review on Tyrosine Kinase Inhibitors in Cats: Current Evidence and Future Directions

“…Apart from the above-mentioned tumors, TK expression and/or TKI treatment has been investigated in feline pulmonary carcinomas [146,147], endometrial adenocarcinoma [46], feline histiocytic disorders [54], renal cell carcinoma [58,59,148,149], iris melanomas [150], granulosa cell tumors [56], adrenal cortex carcinoma [56], thyroid gland carcinoma [56], Non-Hodgkin's lymphoma [56], leiomyosarcoma of the gastrointestinal tract [140,151,152], osteosarcoma [57], oligodendrogliomas and subependymomas [153], colonic malignant peripheral nerve sheath tumors [154], gemistocytic astrocytoma [155], Merkel cell carcinoma [156], pancreatic adenocarcinoma [157,158], chemodectoma [159], tracheal adenocarcinoma [160] and hypereosinophilic syndrome [161].…”

A rare case of cecal malignant peripheral nerve sheath tumor in a dog

“…Gastrointestinal MPNSTs are rarely reported in cats, and only two cases have been reported to our knowledge [ 2 , 18 ]. Ribas et al reported a small intestinal MPNST without metastasis in a 5-year-old female spayed chinchilla cat that was treated with complete surgical excision.…”

“…Boland et al described a colonic MPNST with hepatic metastasis in a 14-year-old male neutered domestic medium-hair cat that was treated with surgical resection and metronomic cyclophosphamide. The cat experienced recurrence, and post-mortem examination identified MPNST within the kidneys and liver 18 months postoperatively [ 2 ].…”

“…In addition, different markers are used to exclude other possible non-angiogenic, non-lymphogenic intestinal mesenchymal tumors [ 13 ]. α-SMA and desmin are used to rule out smooth muscle tumors, whereas CD117 (c-kit) and CD34 are used to rule out gastrointestinal stromal tumors [ 2 , 8 , 18 , 20 ]. In this case, we observed positivity for S-100 protein and NSE and negativity for c-kit and α-SMA.…”

“…Metronomic therapy with cyclophosphamide and piroxicam delays recurrence in dogs after incomplete surgical excision [ 3 , 22 ]. In addition, in a cat with colonic MPNST treated with surgery and metronomic cyclophosphamide, clinical signs recurred 18 months postoperatively [ 2 ]. However, the optimal treatment for gastrointestinal MPNST remains poorly established due to its rare occurrence.…”