Pathology of folliculosebaceous cystic hamartoma

Introduction

Sebaceous follicle cystic hamartoma represents a cutaneous biphasic hamartoma It consists of epithelial and mesenchymal components in varying proportions, typically occurring in adults in the head and neck area. Various pathogenic mechanisms underlying this attached neoplasm has been proposed. However, there is still much controversy over whether it represents a distinct entity or part of an evolutionary spectrum of tricholliculomas (TF). Since the introduction of this entity in 1991, there have been a few case reports documenting a variety of mesenchymal changes observed in FCH, as well as rare and unusual associations.

Histology of folliculosebaceous cystic hamartoma

Follicular cystic hamartoma It is a cutaneous hamartoma of epithelial and mesenchymal elements and focuses mainly on dermis. The epithelial components of folliculosebaceous cystic hamartoma comprise distorted follicular cystic distorted proliferations while mesenchymal components commonly include fibroplasia, vascular and proliferations of adipose tissue.

Scan view shows dilated follicular structure or structures, with radiant matures sebaceous lobes (Figures 1, 2). Surrounding the distorted hair follicles There may be thin anastomosing epithelial strands (Figure 3). the stroma surrounding epithelial units is frequently made up of dense collagen tissue (Figure 1-3) and can show prominent cleft to the surroundings adjacent unaffected dermis (figure 1). Additional stromal changes may include increased vascularity or pockets of adipocytes consistent with the increase in stromal fat (figure 4).

Differential diagnosis of folliculosebaceous cystic hamartoma

Trichofolliculoma: Attempts to distinguish sebaceous trichofolliculoma from folliculosebaceous cystic hamartoma Clinical and histological studies have been performed. The latter has been suggested injury it presents clinically as a hairless papulonodular lesion. HistologicallyFSH demonstrates more prominent stromal mesenchymal abnormalities.

In contrast, sebaceous trichofolliculoma presents clinically as a depressed lesion with a eruption of terminal or hairy hairs. Histologically, there is an almost constant dilatation connection infundibular structure with the epidermis. However, the characteristics described above are not absolute. There have been clinical descriptions of folliculosebaceous cystic hamartoma associated with hair, and hair stems have also been identified within cystic structures in folliculosebaceous cystic hamartoma. Similarly, the finding of a direct connection to the epidermis by the cystic structure is not exclusively found in sebaceous tricholliculoma and has been described in cases of folliculosebaceous cystic hamartoma.