Approximately 2% of cutaneous neoplasms are found in the scalp, but hair cover can prevent timely detection by both patients and physicians, leading to longer disease duration and possibly worse outcomes. In a review article published in the Journal of the Academy of European Dermatology and Venereology, researchers from Italy describe the several types of scalp tumors and their corresponding prognoses and treatment options, seeking to raise awareness of the importance of careful examination of the scalp during consultations.
Scalp tumors can be classified as primary tumors (adnexal, epithelial, melanocytic) or metastatic, extending from distal tumors or spread from contiguous structures. Cutis with adnexa, fibroadipose tissue, lymphatic and vascular systems, and galea aponeurotica comprise the scalp, and their features may contribute to worse prognosis when compared with other locations on the body. Melanoma, basal cell carcinoma (BCC), squamous cell carcinoma (SCC), adnexal tumors, and metastases can be found on the scalp.
Ultraviolet (UV) radiation is a primary contributor to melanomas, both on the scalp and on other areas of the skin. Melanomas of the scalp also tend to have a worse prognosis compared with melanomas in other regions. Self-identification of cutaneous tumors of the scalp is difficult; hairdressers are often the first people to notice scalp melanomas on their clients. Hair cover, can also make clinical diagnosis difficult.
Scalp SCCs may be more common in men than in women, which is possibly explained by the reduced hair cover and the associated lack of UV protection in older men. In immunocompromised patients, SCCs tend to exhibit a more aggressive behavior and have a poorer prognosis compared with other types of carcinomas. Risk factors for BCCs also include UV radiation, in addition to radiotherapy, immunosuppression, and genetic factors. The location of BCCs in women are more often found on the vertex and frontal region, according to some research.
In addition, physicians should be aware that some inflammatory skin conditions “may represent a possible differential diagnosis of SCC, including pustular dermatosis of the scalp, Brunsting-Perry mucous membrane pemphigoid or pemphigus,” the investigators wrote.
In terms of management, the recommended approach is radical surgical excision. Electrodessication and curettage, imiquimod 5% cream, cryosurgery, and photodynamic therapy may be considered for some patients who refuse surgery for some lesions. Alternatively, recent approvals of vismodegib and sonidegib for BCC and cemiplimab for SCC may be valuable options for patients with locally advanced and unresectable scalp tumors.
Although surgery may not be an option in some cases due to lack of skin mobility, Mohs micrographic surgery may be helpful to achieve complete margin control and tissue sparing. A multidisciplinary team comprising otolaryngologists, head, neck and plastic surgeons, and neurosurgeons may be necessary for surgical excisions of locally advanced and deep-infiltrating or giant scalp tumors.
The investigators concluded by emphasizing the importance of a thorough examination of the scalp during routine dermatologic visits. Considering that the prognosis of many scalp tumors is usually not as promising as those in other areas, early diagnosis can greatly affect the outcome of the disease.
Dika E, Patrizi A, Veronesi G, Manuelpillai N, Lambertini M. Malignant cutaneous tumours of the scalp: always remember to examine the head [published online March 2, 2020]. J Eur Acad Dermatol Venereol. doi: 10.1111/jdv.16330