Page 148 - Clinical relevance of current materials for cranial implants

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Chapter 7
DISCUSSION
In this case report the feasibility of a one stage virtual planned surgical removal and reconstruction of a recurrent and previously irradiated cutaneous squamous cell carcinoma with invasion into the underlying skull is presented. Also, the potential complications that may occur and management are discussed.
Cutaneous squamous cell carcinoma (cSCC) of the scalp is not uncommon. Predisposing factors include chronic actinic damage, prior treatment with ionizing radiation, immunosuppression, chronic scarring, and certain genodermatosis16. They represent approximately 2% of all skin cancers, with a male predominance presumably due to androgenic alopecia7,16–18. In contrast, advanced cSCC of the scalp with invasion of the underlying skull has a rare occurrence and clinical decision making is severely hampered by the lack of experience reported in literature.
Non-melanoma skin cancer of the scalp is most commonly staged according to the TNM (tumor, node, metastases) staging system 14. Staging is an important tool in prognostic stratification. The majority of cSCC is detected at an early stage and classified as low risk. Their prognosis is good with a low incidence (< 5%) of metastases19,20. Successful treatment is usually achieved with soft tissue excision and scalp reconstruction using primary closure, local flaps or skin grafting. A small subset of lesions has more unfavorable characteristics, in which the incidence of nodal metastasis is significantly increased (16-47%) and prognosis is worse20–27. Although the exact value of negative prognostic factors is still debated, most authors agree that size of the lesion (>2 cm), depth of invasion (>4 mm), incomplete excision, recurrent setting, differentiation grade (poorly differentiated), presence of perineural or lymphovascular invasion and certain locations (lip, external ear, temple, forehead, anterior scalp) harbor an increased risk for nodal metastasis and/or local recurrence21–24. Patients factors (immunosuppression), particularly in the setting of an organ transplantation, may also play a pivotal role in recurrent disease21,23,24. It is of utmost importance to identify these patients with high risk cSCC to dictate appropriate work up and management strategy.