Cutaneous mastocytosis in Thai children.

BACKGROUND: Mastocytosis is a disorder of mast cells proliferation within various organs, most commonly in the skin. The disease more commonly appears during infancy than adult. OBJECTIVE: To characterize the clinical features, response to therapy and prognosis of cutaneous mastocytosis in children. MATERIAL AND METHOD: A retrospective study of cutaneous mastocytosis was performed at Queen Sirikit National Institute of Child Health during January 1994 to December 2007.All cases were confirmed by histological diagnosis. RESULTS: There were a total of 50 patients. The male to female ratio was 1:1.2. Age at onset of lesions ranged from birth to 7 years. Forty-seven patients (94%) developed skin lesions within the first year of ife. There were 45 cases (90%) of urticaria pigmentosa, 3 cases (6%) of mastocytoma and 2 cases (4%) of diffuse cutaneous mastocytosis. None of the patient had a family history of cutaneous mastocytosis. Most of the children were healthy, except the one who had germ cell ovarian tumor Skin biopsies were performed in all cases and revealed mast cells infiltrate in the dermis. Treatment included oral antihistamine in all cases. Oral mast cell stabilizers were given in 6 patients (12%) and topical corticosteroids in 15 patients (30%). Four patients (8%) were treated with oral prednisolone. The skin lesions resolved only in 1 patient (2%) at age 7.8 years, the others still had skin lesions without systemic symptoms. CONCLUSION: Cutaneous mastocytosis is a benign disease in children without systemic involvement.

Epidemiological assessment of the risk of canine mast cell tumours based on the Kiupel two-grade malignancy classification.

BACKGROUND: The degree of differentiation of mast cell tumours (MCTs) is the most important feature and reflects the morphological characteristics and metastatic potential of the tumour and its likely response to treatment and the prognosis. The aim of this study was to epidemiologically analyse the risk of MCT development in dogs according to breed, age, sex, size and anatomical location of the tumour using the Kiupel grading system. The analysis involved 492 dogs selected based on a histopathological assessment of 2763 canine skin tumours. A logistic regression analysis was performed to determine the odds ratios (ORs) with 95% confidence intervals. RESULTS: Mast cell tumours accounted for 17.8% of all diagnosed canine skin tumours. The highest risk of high-grade MCTs was noted in the Shar-Pei (OR 28.18, P < 0.001) and Weimaraner (OR 6.45, P = 0.023). The highest risk of low-grade MCTs was determined in the Boxer (OR 6.72, P < 0.001), and Pug (OR 6.13, P = 0.027). The scrotum (OR 31.72, P < 0.001), inguinal area (OR 17.69, P < 0.001) and axilla (OR 6.30, P < 0.001) had the highest risk of high-grade MCTs. The risk of high-grade MCTs increased with age and peaked in the oldest dogs, aged 11-16 years (OR 9.55, P < 0.001). A higher risk of low-grade tumours was noted in younger dogs (aged 4-6 years) (OR 8.54, P < 0.001) and females (OR 1.43, P = 0.001). Statistical analysis further revealed a higher risk of both low (OR 3.47, P < 0.001) and high-grade MCTs (OR 1.71, P = 0.006) in medium-sized dogs. CONCLUSIONS: This study demonstrated relationships between Kiupel grading system and phenotypic traits, age and location of canine MCTs confirming the complex biological nature of this tumour.