A 68-year-old fair-skinned man from Delhi presents with a slowly enlarging nodule on his right cheek for the past 18 months. On examination, there is a 1.5 cm pearly nodule with central ulceration and a rolled, waxy border. The lesion bleeds easily on minor trauma. Dermoscopy reveals arborizing vessels. What is the most likely diagnosis?

Explanation

## Clinical Presentation **Key Point:** The classic presentation of basal cell carcinoma (BCC) is a pearly nodule with central ulceration and a rolled, waxy border—often called a "rodent ulcer" when ulcerated. ### Diagnostic Features | Feature | BCC | SCC | Melanoma | |---------|-----|-----|----------| | Border | Rolled, waxy, pearly | Ill-defined, indurated | Irregular, asymmetric | | Surface | Central ulceration common | Keratotic, crusted | Variegated color | | Vessels | Arborizing (tree-like) | Punctate | Atypical | | Growth | Slow (months to years) | Variable | Variable | | Bleeding | Easy on trauma | Less common | Common | **High-Yield:** Arborizing vessels on dermoscopy are pathognomonic for BCC. This finding, combined with the pearly nodule and rolled border, makes BCC the diagnosis. ### Risk Factors in This Patient - **Fair skin** (Fitzpatrick I–II) — major risk factor - **Age >60 years** — cumulative UV exposure - **Chronic sun exposure** — Delhi's high UV index - **Slow growth over 18 months** — typical of BCC (not aggressive like SCC or melanoma) **Clinical Pearl:** BCC is the most common cutaneous malignancy worldwide (~80% of non-melanoma skin cancers). Despite its malignant nature, it has an excellent prognosis because metastasis is extremely rare (<0.1%). ### Pathology Correlation Histologically, BCC shows: - Nests and strands of basaloid cells arising from the epidermis - Peripheral palisading of nuclei - Retraction artifact around tumor nests (pathognomonic) - Mucin-rich stroma **Mnemonic:** **PEARL** = Pearly appearance, Easy bleeding, Arborizing vessels, Rolled border, Long slow growth.