Melanocytic tumours of the nasal planum in cats: 10 cases (2004–2019)

Abstract

Objectives To better characterise signalment, biologic behaviour, and treatment outcome in melanocytic tumours of the nasal planum in cats. Materials and Methods Retrospective study in cats diagnosed with histopathologically confirmed melanocytic tumours on the nasal planum. Results Ten cats were identified with melanocytic tumours of the nasal planum. Pigmentation of the nasal planum seemed to be a predisposing factor. Seven cats were diagnosed histopathologically with a malignant melanoma, three with a benign melanocytoma. One of the cats developed a lymph node metastasis despite diagnosis of a well‐differentiated melanocytic neoplasia. In four cases, a pigmented mass, which was initially stable over a long time, showed a sudden rapid progression suggesting malignant transformation. Treatments included hypofractionated radiation therapy (n = 6) and surgical resection (n = 1). In three cats no further treatment was pursued. Complete (n = 3) and partial (n = 3) remissions were observed in cats treated with radiation therapy; however, all experienced tumour progression or recurrence after a short period of time. Most of the cats (n = 7) had to be euthanased due to tumour progression (median survival time: 265 days). Clinical Significance The present case series provides insights in clinical presentation and clinical outcomes of cats with melanocytic tumours of the nasal planum.

Electrochemotherapy as a treatment option for feline nasal melanoma

“…All animals were euthanased owing to progression of disease, which had caused clinical signs that reduced quality of life (anorexia, apathy and weight loss). 10 At the time of writing, the patient reported herein is currently 9 months post-ECT treatment, with no local tumour recurrence and no clinical signs of disease, showing that, in this instance, ECT gave a significantly more durable response compared with hypofractionated radiation.…”

“…In a retrospective case series of 10 cats with melanocytic tumours of the nasal planum, pigmentation of the nasal planum was found to be a predisposing factor. 10 The cat in this case study also had a pigmented nasal planum.…”

Sentinel Lymph Node Mapping and Biopsy in Cats with Solid Malignancies: An Explorative Study

“…However, a tendency to lymphatic spread and nodal metastases is also reported for feline solid tumors. Nodal metastases have been reported in around 30% of cats with maxilla-facial tumors [ 11 , 28 , 29 ] and in 35% of female cats with mammary gland malignant tumors [ 46 ]. Likewise, in cats with cutaneous MCT, nodal metastases have been detected in 20% of cats with Sabattini’s high-grade cutaneous mast cell tumors [ 41 ], and an association with guarded prognosis has also been demonstrated [ 47 ], further emphasizing the importance of correct nodal staging also in the feline species.…”

“…Comparable data on the feasibility and advantages of incorporation of SLN mapping in the feline species are lacking. A tendency to lymphatic spread and nodal metastases is reported for various feline solid tumors [ 11 , 28 , 29 ]. In a recent study, metastases to the lymph nodes have been documented in 58.8% of cats with MCT, underscoring the importance of nodal assessment also in this species [ 30 ].…”

“…In a recent study, metastases to the lymph nodes have been documented in 58.8% of cats with MCT, underscoring the importance of nodal assessment also in this species [ 30 ]. However, there is still considerable inconsistency among studies on indications and methods for nodal staging in cats, and most studies do not even include information on the status of the lymphatic basin [ 11 , 28 , 29 ]. Furthermore, information on the feasibility and impact on the staging of SLN mapping and biopsy in cats is limited to a few experimental studies [ 31 , 32 ] and a single clinical case of MCT [ 33 ].…”