Abdominal fibromatosis in a young child: a case study and review of the literature

Abstract

Fibromatoses comprise many different entities of well-differentiated fibroblastic proliferation with variable collagen production and form a firm nodular mass. Abdominal fibromatosis is distinguishable from other forms of fibromatosis because of its location and its tendency to occur in women of childbearing age during or following pregnancy. Abdominal fibromatosis in children is an extremely rare condition. A 15-month-old boy presented with an abdominal wall mass that had recently increased in size. Mass excision was perfomed. The tumor was 4.3×4.1 cm and partly circumscribed. Histologically, the tumor was composed of parallel long fascicles of spindle-cells with a uniform appearance. The edges of the resected mass were infiltrative, and the surgical margins were positive. Mitotic figures were <1/10 high power fields. No cellular atypia or necrosis was present. The tumor cells were positive for vimentin and nuclear β-catenin staining.

Keywords: Abdominal wall; Child; Fibromatosis.

Fig. 1

The cut section of the abdominal tumor reveals a grayish-white solid mass with partially irregular edges (arrows).

Fig. 2

Histologic findings. (A, B) The tumor reveals long fascicles of bland spindle-shaped fibroblasts with collagen deposition. (C) The tumor shows infiltrative growth and the surgical margins are positive. (D, E) The tumor cells show nuclear and cytoplasmic β-catenin immunostaining.