Histopathologic Evaluation of Soft Tissue Sarcoma in Nnewi Teaching Hospital, South-East Nigeria: Nine-Years Retrospective Study with Extensive Review of Literature Ezejiofor et al soft tissue sarcoma, South-eastern, Nigeria

Abstract

Background: Malignant soft tissue tumours (STTs), are aggressive mesenchymal neoplasm with marked tendency for distant metastasis and recurrence. Objectives: To study these tumours with respect to age, sex, anatomic site, histologic types and to determine the data base for these tumours in Nnewi, and compare findings with the world at large. Methodology: This study reviewed all histologically diagnosed malignant STTs at Histopathology department of Nnamdi Azikiwe University Teaching Hospital (NAUTH), Nnewi, Nigeria over 9-year period. Immunohistochemical stains were selected and applied in difficult cases with 2 or 3 differential diagnosis. Results: Of 1606 malignancies diagnosed in the study period, 364 cases were soft tissue lesions, of which malignant (STTs) were 27.5% (n=100) while 68.4% (n=249) were benign STTs. Malignant STTs accounted for 6.2% of total malignancies under review.  There is a slight female preponderance with Male to female ratio of 1: 1.1 and a mean age of 40.25 years ± 22.35. Bimodal distributions of sarcomas were seen in this study; 10-40 years (n=47) and 50-80 years (n=37) with 15% of cases seen in individual less than 15 years and 47% seen in persons 50 years and above. Most common malignant STTs according to tumour differentiation were Fibroblastic tumours (n=23; 23%) followed by Tumours of uncertain differentiation (n=22; 22%). Kaposi sarcoma was the predominant histological types accounting for 20% (n=20) of all malignant STT and 5.49% of all STTs. Sarcoma Not Otherwise Specified (NOS) was the second commonest tumour and consisted of 15% (n=15), followed by rhabdomyosarcoma 11 cases (11%), while malignant peripheral nerve sheet tumours (MPNST) and DFSP were 10 cases (10%) each. Kaposi sarcomas, sarcoma NOS and DFSP had peak occurrence at four decades while rhabdomyosarcoma occurs more in childhood to young adults between ages of 0-30 years.Conclusion. Kaposi sarcoma was the commonest malignant STT in our environment followed by sarcoma NOS then rhabdomyosarcoma. Extremities and trunk were the commonest locations in our study.