Clinical and Histopathological Characteristics of Tumors Arising in Seborrheic Keratosis: A Study of 1365 Cases

Abstract

Objective:The aim of this study was to describe the clinical and histopathological characteristics of seborrheic keratosis (SK) with secondary tumor and identify associated factors. Methods: This study was a monocentric retrospective case-control study describing the factors associated with the development of tumors in SK. A total of 1365 patients with SK were admitted to our department between 2018 and 2021. All of the histopathological specimens and medical records of these patients were reviewed. We compared the data of 36 patients with tumors arising in SK with those of the remaining 1329 patients with only SK, which were designated the control group. Results: The incidence of tumors arising in SK that were biopsied was 2.6%. The tumor types included squamous cell carcinoma (SCC), basal cell carcinoma (BCC) and keratoacanthoma (KA). Compared with other patients with SK, elderly patients with immunosuppression, patients presenting surrounding erythema or ulceration, and those with SK in exposed areas had an increased possibility of developing a secondary tumor. Tumors arising within SK have the histopathological features of ulceration, cytologic atypia, mitosis, "malignant horn", trabecular cell cords, solar elastosis and severe inflammatory infiltration in the dermis. Conclusion: SK can show malignant progression in a small fraction of SK cases that are biopsied. This study is the first report on the clinical and histopathological characteristics of tumors arising in SK and identifies relevant factors in an Asian population.

Perioral Clonal Variant of Seborrheic Keratosis: Diagnostic Challenges

“…Clinical features like ulceration and erythema around SK lesions have a possible role in tumour formation. Criteria for diagnosis of tumour in SK are cytologic atypia, mitosis with similar features of SK, hyperkeratosis, parakeratosis, papillomatosis and pseudo horn cyst [ 18 , 19 ].…”

Diagnostic Utility of TUNEL Staining for Degenerative Keratoacanthoma Requiring Pathologic Differentiation from Seborrheic Keratosis

“…It may suggest a strong antitumor immunity in the background. Although there have been reports of keratoacanthoma secondary to seborrheic keratosis [6], these stains are useful in discriminating between pathological keratoacanthoma and seborrheic keratosis.…”

Is Seborrheic Keratosis Really Benign?: A Case Report of Seborrheic Keratosis with Malignant Transformation

“…[ 2 3 ] Accumulation of p16 and somatic alteration in FGFR3, PIK3CA, HRAS, KRAS, AKT1 , EGFR, CDKN2A, TERT and DHPH3 have been reported. [ 3 4 ] Seborrheic keratoses are grouped into seven histological variants: acanthotic, hyperkeratotic, adenoid, clonal, Bowenoid, irritated and melanoacanthoma. Treatment is not required except for cosmetic reasons.…”

“…Though SK is considered to be benign, the incidence of tumorigenesis is reported to be 1.4%–7%. [ 4 ] Malignant transformation is more commonly seen in the elderly and in the head area associated with symptoms like pruritus, ulceration and pain. Potential risk factors include prolonged sun damage and radiation exposure.…”

“…The malignancies reported arising secondarily from SKs mainly are basal cell carcinoma and squamous cell carcinoma, while others include melanoma, keratoacanthoma, adenocarcinoma, trichilemmal carcinoma, eccrine porocarcinoma and primary cutaneous ganglioneuroma. [ 4 ]…”