Multicentric cutaneous mast cell tumor treated with lomustine (CCNU)

A. Muller (1), E. Guaguère (1), C.Muller (1), F. Degorce-Rubiales (2), P. Devauchelle (3), M. Delverdier (4)
(1) Clinique Saint-Bernard, 598 avenue de Dunkerque 59160 Lomme, France – (2) LAPVSO, 129 route de Blagnac 31201 Toulouse, France – (3) Centre de Cancérologie Vétérinaire, 7 avenue du Général de Gaulle 94700 Maisons-Alfort – (4) Ecole Nationale Vétérinaire de Toulouse, 23 chemin des Capelles 31076 Toulouse, France
This communication was presented (Poster) at the ESVD Congress in Nice (2002).

Clinical findings

A 3.5-year-old female Labrador was presented for multiple cutaneous nodules (about 30), which had developed over the previous month, initially on the face (dorsum of the muzzle, pinnae) then on other body areas (neck, ventral abdomen). The lesions were dermal, raised, often ulcerated and of variable size (3 mm to 4 cm). Some coalescent lesions formed plaques. Pruritus was moderate. Differential diagnosis included multicentric cutaneous mast cell tumor, cutaneous histiocytosis, eosinophilic granuloma or eosinophilic furunculosis.

Multicentric cutaneous mast cell tumor treated with lomustine (CCNU) Multicentric cutaneous mast cell tumor treated with lomustine (CCNU) Multicentric cutaneous mast cell tumor treated with lomustine (CCNU)

Laboratory investigations

Cytology (impression smear and needle punction) showed several little differentiated mast cells and eosinophils.
Histopathology (biopsies of nodules) revealed a grade II MCMT (numerous atypic mast cells with mitoses) with collagenolysis and eosinophilic furunculosis areas (F. Degorce-Rubiales, LAPVSO). The nature of the tumor was confirmed by toluidine blue stain (metachromasia).
Immunohistochemical study showed a Ki-67 labeling index > 10%, which was a poorer prognosis (Pr M. Delverdier, ENVT).

Multicentric cutaneous mast cell tumor treated with lomustine (CCNU)

Extension overview

Ganglionic cytology, thoracic radiography and abdominal ultrasonography were negative. CBCs and biochemical profile were within interval values.

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