Giant neglected cutaneous squamous cell carcinoma of the scalp with full-thickness calvarial erosion and early fatal outcome: CT findings and treatment-planning implications.

Cutaneous squamous cell carcinoma is the second most common skin malignancy. When located on the scalp, it carries an increased risk of local aggressiveness, particularly bone invasion of the calvarium. Computed tomography plays a key role in evaluating locoregional extent and guiding multidisciplinary treatment decisions. We report a 64-year-old woman with a history of chronic sun exposure from a rural area, referred for head CT after a 6-year history of a progressively enlarging scalp lesion. Clinical examination showed a large exophytic mass measuring 17 × 15 × 3.5 cm, with a cauliflower-like, hemorrhagic and crusted appearance and clinical features suggestive of secondary infection. Head CT before and after iodinated contrast revealed a large heterogeneous soft tissue mass of the left parieto-temporo-occipital scalp, heterogeneously enhancing, with full-thickness erosion of the underlying calvarium. Cervical CT showed no suspicious lymphadenopathy. Chest CT showed no evidence of thoracic metastatic disease. Histopathology confirmed a well-differentiated keratinizing invasive squamous cell carcinoma without perineural invasion. At the multidisciplinary tumor board, given the giant size of the lesion, the anticipated extent of the resulting surgical defect, and the expected inability to achieve adequate wound closure and reconstruction, the tumor was considered unresectable in our local setting. Palliative external-beam radiotherapy of the scalp (30 Gy in 10 fractions) was selected as the primary treatment option. The patient died after two fractions, before any post-treatment evaluation could be performed. Locally advanced scalp cutaneous squamous cell carcinoma with bone invasion is a diagnostic and therapeutic challenge. Computed tomography is the first-line modality for evaluating bone involvement; magnetic resonance imaging remains more sensitive for the detection of subtle dural or dural venous sinus involvement. Full-thickness calvarial erosion is consistent with locally advanced disease, at least clinical T4a. When surgery and reconstruction are not feasible, external-beam radiotherapy may be the primary treatment option, within a multidisciplinary decision-making framework. This case underscores the central role of computed tomography in characterizing the bone extent of locally advanced scalp cutaneous squamous cell carcinoma and in guiding multidisciplinary therapeutic decisions. The multi-year diagnostic delay and the patient's early death after two fractions of radiotherapy illustrate the severe clinical course of giant neglected scalp cutaneous squamous cell carcinoma with calvarial invasion.