RESUMO
Trichilemmal carcinoma is a rare tumour derived from the outer root sheath of hair follicles . It can be difficult to distinguish both clinically and histologically from other skin lesions, particularly squamous cell carcinoma. We present the case of a 62-year-old female with a 20-year history of three 1-cm cysts on her scalp. Over a six-month period, a cyst overlying the occiput had become painful and grown in size. The general practitioner and subsequently local emergency department suspected infection. The lesion was incised, and the patient was treated with oral antibiotics. At the time of surgical excision, the lesion measured 3 x 4 cm. Microscopic examination identified rounded dermal lobules of squamous epithelium with trichilemmal keratinization, in keeping with a pre-existing pilar cyst. There were areas with nuclear pleomorphism, mitoses and an infiltrative architecture. A diagnosis of trichilemmal carcinoma arising in a pilar cyst was made. Trichilemmal carcinomas are considered to be a low-grade tumour, but they have the potential to spread to lymph nodes and to metastasise to distant sites in the body, therefore adequate excision and appropriate follow-up are required.
RESUMO
Para-phenylenediamine (PPD) is the commonest and most well-known component of hair dyes. Oxidative hair dyes and dark henna temporary tattoos contain PPD. Individuals may be sensitized to PPD by temporary henna tattooing in addition to dyeing their hair. PPD allergy can cause severe reactions and may result in complications. In recent years, frequency of positive patch test reactions to PPD has been increasing. Cross-sensitization to other contact allergens may occur, in particular to other hair dye components. Hairdressers are at a high risk for PPD allergy and require counseling regarding techniques to minimize exposure and protective measures while handling hair dye. We focus this review on the current perspectives of diagnosis and management of PPD allergy.
