Abstract

Malignant soft tissue tumours account for less than 1% of overall human burden of
malignant tumours. Previously considered rare, increasing incidences of these tumours have
been noted worldwide.
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This ten year retrospective histopathological review was carried out to identify, classify,
grade, and determine the pattern, frequency, age and sex distribution of malignant soft
tissue tumours received in the histopathology department of Aminu Kano Teaching Hospital
(AKTH) Kano, from January 1999 to December 2008.
The study comprised of all cases of soft tissue sarcoma diagnosed over the 10 year review
period. Laboratory request forms and duplicate copies of histological reports were retrieved
and relevant clinical information such as age, sex, site and histological types of the tumours
were extracted. Corresponding haematoxylin and eosin stained slides were reviewed and
evaluated. Special stains such as PTAH and reticulin were used for some cases and
Immunohistochemistry was employed in a few others. The tumours were classified
according to WHO classification and graded using the FNCLCC grading system and the
results analyzed using frequency tables, pie and bar charts.
A total of 264 cases of soft tissue sarcomas representing 30.2% of all soft tissue tumours
were recorded. This accounted for 8.8% of 2997 malignant tumours of varying histological
types received over the same period. One hundred and sixty-two males and 102 females
were recorded with a male to female ratio of 1.6: 1. The age range was between 3 months
and 89 years with a mean age of 39.0 years. Kaposi sarcoma was the predominant
histological type with 56 cases (21.2%). This was followed by rhabdomyosarcoma with 54
(20.5%) cases, Dermatofibrosarcoma with 52 (19.7%) cases, and liposarcoma with 3 (6.0%)
cases. The most common site of affectation was the lower limb with 73 (27.7%) cases,
followed by the trunk with 66 (25.0%) cases, head and neck with 45 (17.0%) cases, and
upper limb with 35 (13.3%) cases. The study found significant association between tumour
grade and age (p<0.05), but no such association was found between grade of the tumour
and sex of the patients (p>0.05).
Soft tissue sarcomas were found to be more common than otherwise thought and Kaposi
sarcoma was the predominant histological subtype commonly affecting young adults. Late
presentation is a major challenge in our environment and public awareness campaign will
help ameliorate this trend. The advent of Immunohistochemistry in our centre has ensured
prompt and more accurate diagnosis of these tumours.

HISTOPATHOLOGICAL STUDY OF SOFT TISSUE SARCOMAS SEEN AT AMINU KANO TEACHING HOSPITAL, KANO FROM JANUARY 1999 TO DECEMBER 2008