Resident Rounds Part III: Case Report: Metastatic Cutaneous Squamous Cell Carcinoma in an African American Female

CLINICAL PRESENTATIONA 52-year-old African American female with a history of intellectual disability, hypertension, left middle cere- bral aneurysm, hyperlipidemia, and a 90-pack-per-year history of smoking presented with a large, painful, fungating, bleeding 9.0 cm x 6.5 cm tumor adherent to her occipital scalp (Figure 1, Panel A) for 4 years. Biopsy revealed a poorly differentiated squamous cell carcinoma (Figure 1, Panel B). Computed tomography (CT) and whole body positron emission tomography (PET-CT) demonstrated invasion of the occipitalis muscle and subadjacent occipital bone (Figure 1, Panel C, arrow), along with metastatic cervical adenopathy (Figure 1, Panels D and E, arrows). The patient underwent radical excision of the tumor, including skin and underlying muscle, fascia, and periosteum, which revealed perineural and lymphovascular invasion with positive deep margins. Occipital craniectomy and bilateral posterolateral neck dissection with xenograft placement were also performed, revealing 3 metastatic lymph nodes. After reconstruction, the patient was referred to radiation oncology for adjuvant radiation treatment. Repeat CT after radiation demonstrated gross tumor recurrence in the skull and posterior upper neck vasculature, with increased invasion of the occipital bone with likely dural but no frank parenchymal invasion. Additionally, new metastatic lesions within the lungs were visualized (Figure 2, arrows). At this juncture, the patient has opted for only supportive management. DISCUSSION An estimated 700,000 cases of cutaneous squamous cell carcinoma (cSCC) are diagnosed annually.⁶ While the overall majority of cSCCs are low-risk tumors with a favorable prognosis, a subset of tumors is considered "high-risk" cSCC (HRcSCC), demonstrating the need for a more aggressive clinical course, with a potential for local recurrence or metastasis. The annual incidence of metastasis is approximately 4%, though this is likely to be an underestimation as epidemiological analysis is hindered by the lack of a national cancer registry for cSCC.^7,8 The 5-year overall survival of a patient is reduced by 50% with the presence of metastasis, making both early identi cation of this subset and prompt initiation of aggressive management of paramount importance.⁵ Multiple staging algorithms have been published in an attempt to help risk stratify cSCCs based on pro- posed tumor characteristics thought to predict risk of metastasis, though no official guidelines have been formally validated.⁸ As defined by the American Joint Committee on Cancer (AJCC) in 2002, the intended purpose of cancer staging is to distinctly