Aggressive fibromatosis in pediatric population-A case series

Abstract

Introduction: Aggressive fibromatosis or Desmoid fibromatosis is a benign tumor which originated form mesenchymal tissues of the body. This tumor has strong potential of recurrence and infiltration but it does not metastasize to other organs of the body. This case series is focused to determine the treatment outcomes for pediatric patients of aggressive fibromatosis.

Methodology: It is a retrospective case series conducted on 7 patients presented to section of Orthopedics, department of surgery of our institute in Karachi. We included all the cases of pediatric patients from 1 to 16 years, with biopsy proven fibromatosis from January 2000 to December 2015.

Presentation of cases: Out of 7 pediatric patients, there were 6 (85.7%) males and 1 (14.3%) female patient. The median age was 6 years IQR (5-11) years. Gluteal region was the most common site of disease. Four patients (57.1%) had positive tumor margins while three (42.9%) had negative margins. Out of 7 patients, 4 patients (57.1%) had recurrent disease and they had positive margins. The median Disease Free survival time was 14 months and there was no expiry of patients.

Conclusion & recommendation: The conclusion of our study was that aggressive fibromatosis is more prevalent in children below 15 years of age and disease burden is higher in male gender. Positive margins after surgery indicate a high risk for disease recurrence therefore; primary surgery with negative margins is the treatment of choice for children with AF. However, we recommend that multicenter trials should be conducted in the future to clarify the role of adjuvant treatment for patients with pediatric AF.

Keywords: Aggressive fibromatosis; Disease free survival; Pediatric patients; Positive margins.

Fig. 1

MRI pelvis of fibromatosis of right gluteal region. Coronal plane showing mass infiltrating in the adjacent gluteus muscles and entering in pelvis. Axial plane showing no lymphadenopathy and normal vessels.

Fig. 2

Pre-operative (incisional) biopsy. [A] Low power view of the lesion exhibiting fascicles of spindle cells against fibrotic background. (H&E stain; 100x magnification) [B] High power view of spindle cells with bland, elongated and vesicular nuclei. (H&E stain; 400× magnification) [C] Spindle cells showing patchy expression for alpha smooth muscle actin and [D] patchy nuclear expression for β-Catenin IHC stains. (400× magnification).

Fig. 3

Post-operative (excisional) biopsy. [A] Low power view of the lesion exhibiting fascicles of spindle cells against fibrotic background. (H&E stain; 100× magnification) [B] High power view of spindle cells with bland, elongated and vesicular nuclei. (H&E stain; 400× magnification) [C] Entrapped atrophic skeletal muscle fibers (short arrows) and lymphoid aggregate (large arrow). (H&E stain; 200× magnification) [D] Entrapped adipose tissue (lshort arrow). (H&E stain; 200× magnification).