Pigmented basal cell carcinoma mimicking nodular melanoma

• Published in: BMJ case reports Vol. 17; no. 9; p. e261362
• Main Authors: Purushottama, Manila, Ashwini, Shankar Bharathi, Ranugha, Poovanur Sadasivam Subramanian, Basavaraj, Vijaya
• Format: Journal Article
• Language: English
• Published: England BMJ Publishing Group Ltd 25.09.2024; BMJ Publishing Group LTD
• Subjects: Adult; Apoptosis; Asymptomatic; Biopsy; Carcinoma, Basal Cell - diagnosis; Carcinoma, Basal Cell - diagnostic imaging; Carcinoma, Basal Cell - pathology; Cysts; Dermatological; Dermatology; Dermoscopy; Diagnosis, Differential; Female; Head and neck cancer; Histopathology; Humans; Hyperpigmentation - pathology; Keratin; Medical prognosis; Melanoma; Melanoma - diagnosis; Melanoma - pathology; Mortality; Pathology; Patients; Skin cancer; Skin Neoplasms - diagnosis; Skin Neoplasms - pathology; Pathology; Head and neck cancer; Dermatological; Skin cancer
• ISSN: 1757-790X; 1757-790X
• DOI: 10.1136/bcr-2024-261362

The most common form of primary skin cancer is basal cell carcinoma (BCC). Pigmented BCC is a less common clinical presentation in BCC spectrum, where the tumour contains pigment. Some cases can exhibit morphological features that mimic those of nodular melanoma (NM). We present a woman in her late 40’s who had an asymptomatic firm, hyperpigmented nodule on the right cheek resembling pigmented NM. Dermoscopy showed diffuse hyperpigmentation with irregular shiny surface and a solitary haemorrhagic crust. Melanoacanthoma and irritated seborrheic keratosis were the other differentials considered. Punch biopsy showed features of trichoepithelioma initially, subsequent complete excision was suggestive of pigmented BCC.Mortality related to BCC is rare, whereas NM is aggressive. Hence, clinicians need to be aware of this rare presentation of BCC as a hyperpigmented nodule, particularly in dark-skinned individuals. Timely differentiation between melanoma and BCC is crucial given their differing prognosis.