Fibrous hamartoma of infancy of rare localization, clinical cases

Abstract

Fibrous hamartoma of infancy (FHI) is a rare tumor, accounting for less than 2% of soft tissue tumors occurring in the first year of life. The tumor arises from the subcutaneous tissue and is most often found in the armpit, then in the shoulder, groin and chest wall. The characteristic microscopic appearance of FHI is the presence of three tissue types in varying proportions: well-defined bundles of dense fibrous connective tissue, primitive mesenchyme (organized in nests, concentric whorls, or bands), and intermediate mature adipose tissue. Surgical removal is the main choice of treatment for this pathology. We report 2 cases of rare FHI localized in the gluteal region and the region of the posterior upper third of the thigh. At the same time, in one observation, the lesion affected only the subcutaneous fat, and in the second, a widespread invasive process in the muscles was noted. Despite the benign nature of the tumor, its spread is characterized by invasive growth (it does not have a capsule and a clear border with the surrounding tissues), which can cause difficulties for surgeons during the primary operation in determining the boundaries of FHI removal. For this purpose, we consider it expedient to use an express biopsy during surgery.