Malignant smooth muscle tumours of soft tissue--a demographic and clinicopathological study at a tertiary care hospital.
OBJECTIVE
To determine the demographic characteristics and distribution of various reported prognostic factors of leiomyosarcoma (LMS) among subjects reporting to histopathology diagnostic centers of Aga Khan University (AKU) all over Pakistan between 2000-2004.


METHODS
This study analyzed 205 consecutive confirmed cases of LMS received during a period of four years. The data regarding age, sex and size of tumor was obtained from the pathology medical records. Data on grade and positivity of immunohistochemical stains was assessed and all the variables analyzed using SPSS version 12.5.


RESULTS
Of the 205 specimens of LMS, 31 were received as blocks for second opinion. A hundred specimens were multiple fragments, and 74 were intact masses. Of the latter, 40% had clear margins. The mean size of the tumor was 7.23 cms. (95% CI 6.1; 8.4). There were no cases of childhood LMS. Teenage LMS comprised 3% of all tumors. Grade 1 tumors were 16.6% of the total, 56.6% were grade 2, and 8.5% were grade 3. Vimentin positivity was observed in 97% of the tumors, desmin positivity in 56.7%, HHF35 positivity in 81.0%, s-100 positivity in 15.6% and cytokeratin positivity in 11% of the cases. The median age of LMS patients was 48.4 years, the mean age was 48.6 years (95% CI 45.9; 50.8) and male to female ratio was 1:1.2. The malignancy occurred a decade earlier in the females as compared to the males. The mean age of male cases was 52.3 years (95% CI 48.8; 55.8); and of females was 45.2 years (95% CI 41.8; 48.6). The mean age of teenage LMS was 17.2 years (95% CI 15.6; 18.7). The most common symptom was a painless swelling. The most common sites were lower limb (24.4%) and pelvis (24.4%) followed by abdomen (20.6%) and head and neck (12.7%). The least common sites were upper limb and chest (8.0% each). Seventy five percent of the tumors with involved margins were more than 5.0 cms. in size whereas 47% of tumors with free margins were above 5.0 cms. in size. Approximately half the tumors in the males were less than 5.0 cms, as compared with 31.0% in the females. LMS in the extremities was equally common in both genders, but trunk LMS was nearly twice as common in the females.


CONCLUSIONS
In our population, leiomyosarcoma occurs at a relatively younger age, has a late presentation; is more common in females as compared to males and usually excised incompletely. No genetic study for LMS has been published in Pakistan; these studies are recommended to determine the biological pattern of LMS in our population.
Shah
Hamidullah
H
Department of Pathology and Microbiology, Aga Khan University Hospital, Karachi.
Bhurgri
Yasmin
Y
Pervez
Shahid
S
D000199:Actins / Q000032:analysis; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D003893:Desmin / Q000032:analysis; D005260:Female; D006761:Hospitals; D006801:Humans; D007150:Immunohistochemistry; D007633:Keratins / Q000032:analysis; D007890:Leiomyosarcoma / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D009418:S100 Proteins / Q000032:analysis; D012737:Sex Factors; D014746:Vimentin / Q000032:analysis
D000199:Actins; D003893:Desmin; D009418:S100 Proteins; D014746:Vimentin; D007633:Keratins