A HISTOPATHOLOGICAL REVIEW OF SOFT TISSUE SARCOMAS SEEN AT THE AHMADU BELLO UNIVERSITY TEACHING HOSPITAL, ZARIA NIGERIA (2004-2013)

Abstract

Introduction:Soft tissue sarcomas are a large group of malignant tumours which are predominantly mesodermal in origin. The world age standardized annual incidence rates for these tumours are 2.6 and 1.8/100,000 for males and females respectively. The overall incidence of soft tissue sarcomas in Europe is 3-4/100,000. These tumours make up approximately 1% to 2%of all adult malignancies, out of which 3,660 to 4,000 deaths occur. Most studies done on soft tissue sarcomas in our environment are hospital based and they show an increasing trend in prevalence.In view of this, reviewing the histopathological pattern of these tumours in Zaria according to diagnosis, grade and pattern of distribution was necessary.
Method:This study was based on a retrospective analysis of all specimen submitted and diagnosed as soft tissue sarcomas in the department of Pathology, Ahmadu Bello University Teaching Hospital Zaria Nigeria within the study period (2004-2013) using conventional histochemistry and immunohistochemistry to characterize the lesions.Histological subtypes
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were classified according to the 2005 WHO classification and grading was based on the FNCLCC grading system.The collated data were analysed using Statistical Program for Social Sciences (SPSS) Version 21.0.
Results:A total of 27,483 surgical biopsies were received during the study period, out of which 545 cases (2.0%) were reported as soft tissue sarcomas. These tumours made up 10.8% of all cancers seen.There was a higher male preponderance with 335 cases (61.5%) males and 210 (38.5%) females and male to female ratio of 1.6:1. The peak incidence was seen in the fifth decade which constituted 19.4%.Kaposi Sarcoma 27.7%, Rhabdomyosarcoma 19.5%, DermatofibrosarcomaProtuberans13.9%,Malignant Fibrous Histiocytoma8.6% and Fibrosarcoma 6.8% were the most common histological subtypes seen in decreasing order. Most cases involved the lower limbs 173 cases (31.7%). A higher number of high grade tumourswith 219 cases (61.4%) as compared to low grade tumourswith 141 cases (39.6%) were recorded.
Conclusion:Soft tissue sarcomas are not uncommon in Zaria.The relative higher prevalence seen in Zaria as compared to developed countries is associated with hospital based data used in this study as compared to population based data used elsewhere. Most cases reported over the 10 years study period adhered to the WHO 2005 Classification system. A HISTOPATHOLOGICAL REVIEW OF SOFT TISSUE SARCOMAS SEEN AT THE AHMADU BELLO UNIVERSITY TEACHING HOSPITAL, ZARIA NIGERIA (2004-2013)