Pattern of adipose tissue tumors in Ahmadu Bello Universty Teaching Hospital, Zaria, Nigeria

Background: Adipose tumors are the most common soft tissue tumors in humans. The reported incidence of lipoma is probably less than the actual incidence because of its insidious growth pattern and minimal associated symptoms. Objective: The objective of this study is to document the pattern of these tumors in a tertiary hospital in Northern Nigeria. Materials and Method: This is a retrospective study of all diagnosed adipose tissue tumor over a 10-year period (January 2002 to December 2011), in the Department of Pathology, Ahmadu Bello University Teaching Hospital. Tissue biopsies fixed in 10% formalin and stained routinely with hematoxylin and eosin were studied. Biodata and sites of involvement were retrieved from patients′ requisition cards. Results: Four hundred and three adipose tissue tumors were diagnosed during this period. Three hundred and ninety-five (98.0%) of the tumors were benign, while 8 (2.0%) were malignant. The male to female distribution was 197 and 206, respectively. Patients ages ranged from 3 months to 75 years with a peak age distribution in the fifth decade (23.6%). The most common site of involvement was the trunk (38.0%), followed by the head and neck region (21.3%) and lower limbs (17.4%). Conventional lipoma was the most common benign tumor, accounting for 328 cases (81.4%), while myxoid liposarcoma was the most common malignant tumor with 4 cases (1.0%). Conclusion: Adipose tissue tumors are not uncommon in our setting and accounted for 6.0% of all tumors seen within the study period. There is a slight female preponderance and the trunk is the most common site of involvement. Benign tumors formed the bulk of lesions recorded.