Abstract
Cutaneous invasive pigmented squamous cell carcinoma (SCC) is rare. There have previously been only a few case reports or small case series in the English literature [1–13]. In the largest published study there were five cases of pigmented invasive SCC in 46,791 archived cases of invasive SCC (approximately 0.01%) [2]. This compares to pigmented SCC in-situ (pigmented Bowen’s disease) in which the largest study found 52 of 951 (5.5%) consecutive cases of SCC in-situ to be pigmented [14]. The differential diagnosis of pigmented invasive SCC includes benign and malignant melanocytic neoplasms (melanoma and nevus) as well as pigmented types of benign and malignant epithelial neoplasms such as basal cell carcinoma (BCC), actinic keratosis (AK), SCC in-situ, seborrheic keratosis and melanoacanthoma [1, 12]. Our search has revealed five cases of pigmented invasive SCC with a description of dermatoscopy features [1, 9, 10, 12, 13] and in none of those cases was the diagnosis predicted.
Highlights
Case reportCutaneous invasive pigmented squamous cell carcinoma (SCC) is rare
In 1997 Kossard et al reported a case of a 79-year-old man with a 5 mm pigmented invasive SCC of the ear [1]
Invasive pigmented SCC was considered, and this was confirmed histopathologically. They described the epiluminescent microscopy findings of “... a diffuse grey-blue colour, but the nodule lacked a peripheral pigment network and had no evident milia-like cysts.”. They considered a differential diagnosis of nodular melanoma, pigmented basal cell carcinoma (BCC), irritated seborrheic keratosis and thrombosed hemangioma
Summary
Cutaneous invasive pigmented squamous cell carcinoma (SCC) is rare. There have previously been only a few case reports or small case series in the English literature [1,2,3,4,5,6,7,8,9,10,11,12,13]. In the largest published study there were five cases of pigmented invasive SCC in 46,791 archived cases of invasive SCC (approximately 0.01%) [2]. A new raised pigmented skin lesion 6 mm in diameter was discovered on his right cheek (Figure 1). It had not been observed at his previous examination six months earlier. None of the treated non-melanoma skin cancers had been pigmented. (Figure 2) the peri-lesional skin was white in between the red vascular plexus. It was signed out by the reporting pathologist as a “focally pigmented, moderately well differentiated acantholytic squamous cell carcinoma extending to mid-dermis.” (Figures 3–5)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
