Clinico-Histopathological Features of Cutaneous Squamous Cell Carcinoma, Keratoacanthoma, and Bowen’s Disease

Abstract

Background: Cutaneous squamous cell carcinoma (SCC) is the second most common form of skin cancer after basal cell carcinoma. Ultraviolet (UV) radiation is the primary risk factor in the development of cutaneous squamous cell carcinoma and its precursor lesions. Bowen disease (BD) is squamous cell carcinoma in situ , and keratoacanthoma (KA) is considered a low-grade SCC. The diagnosis of these conditions requires clinical and histological assessment. Objective: Clinical and histopathological evaluation of squamous cell carcinoma, keratoacanthoma and Bowen’s disease. Patients and Methods : This study is a retrospective study carried out at the Dermatology Center, Medical City/Teaching Hospital, including patients diagnosed with SCC, KA, and BD during a period extending from January 2016 until October 2023. A total of 55 patients were included. Clinical information was recorded, and the histopathological slides were reviewed. Other precursor lesions, such as actinic keratosis, were not included in the analysis, as the objective was to examine only lesions with confirmed invasive or in-situ squamous differentiation. This deliberate exclusion was intended to maintain diagnostic consistency and allow for more detailed histopathological comparisons within the selected lesion types. Results: Forty-one out of 55 patients were males and 14 were females. Regarding SCC, males constituted 77.8% and females 22.2%. The most common age group was the 7th decade, with a mean age of 60.5 years. The mean duration was 10 months, and the most common site of the lesions was the head (83.3%). Histologically, the most common finding detected was squamous eddies (83%), while nesting was detected in 69.4% and pearl horns in 52.8%. Dermal infiltrate was composed mainly of lymphocytes; plasma cells and eosinophils were also detected. The acantholytic type constituted 19.4% of cases, and one case was spindle cell SCC. Regarding the degree of differentiation, moderately differentiated SCCs were the most common (79.8%). For KA, males constituted 72.8% and females 27.3%. The most common age group was the 6th decade. The mean duration was 4.2 months, and the most common site of the lesions was the head (72.7%). Histologically, a crater, glassy eosinophilic appearance and eosinophilic infiltration were found in all cases. For BD, males constituted 62.5% and females 37.5%. The most common age group was the 7th decade. The mean duration was 9.5 months, and the most common site of the lesions was the head (62.5%). Histologically, the eye liner sign was found in 50% and acantholysis in 37% of cases. Conclusion: This paper retrospectively analyzes the clinical and histopathological features of cutaneous squamous cell carcinoma (SCC), keratoacanthoma (KA), and Bowen’s disease (BD) in 55 Iraqi patients from 2016 to 2023. The study finds that moderately differentiated SCC was the most common diagnosis, predominantly affecting the head in older males. The paper details the specific histological characteristics observed for each condition and compares these findings to existing literature. Most cases of SCC were moderately differentiated. The head was the most common location for SCC, KA and BD.