Follicular porokeratosis: four new cases.

Porokeratosis, a disorder of keratinisation, is clinically characterized by the presence of annular plaques with a surrounding keratotic ridge. Clinical variants include linear, disseminated superficial actinic, verrucous/hypertrophic, disseminated eruptive, palmoplantar and porokeratosis of Mibelli (one or two typical plaques with atrophic centre and guttered keratotic rim). All of these subtypes share the histological feature of a cornoid lamella, characterized by a column of 'stacked' parakeratosis with focal absence of the granular layer, and dysmaturation (prematurely keratinised cells in the upper spinous layer). In recent years, a proposed new subtype, follicular porokeratosis (FP_, has been described, in which the cornoid lamella are exclusively located in the follicular ostia. We present four new cases that showed typical histological features of FP.

Traumatic myositis ossificans of the superior belly of the omohyoid.

The first case of traumatic myositis ossificans (TMO) involving a strap muscle of the neck is reported. TMO typically presents with an unresolved mass following trauma or surgery, requiring differentiation from other soft tissue and bone neoplasms. Opacification may be present on soft tissue X-rays. Computed tomography (CT) scan may demonstrate a characteristic zoning phenomenon to establish the diagnosis. The disorder is frequently self-limiting but surgery may be required for persistent symptoms.