Occult Basal Cell Carcinoma Arising in Seborrheic Keratosis

Abstract

The present study reports a case of an occult basal cell carcinoma that arose in seborrheic keratosis. The patient was a fifty-six-year-old male who presented with a dark brown plaque on his back. Clinically, the lesion demonstrated no nodules or ulcerations suggesting that it was malignant. However, histopathological analysis of the lesion revealed an atypical basaloid cell mass that appeared to be a solid basal cell carcinoma beneath and surrounded by a seborrheic keratosis lesion. Thus, the coexistence of basal cell carcinoma and seborrheic keratosis is possible and should be considered when a malignant change in seborrheic keratosis is apparent.

Seborrhoeic keratosis or occult malignant neoplasm of the skin?

“…Basal cell carcinoma is the most common type of malignant skin neoplasm associated with seborrhoeic keratosis. 6,18 This was also apparent in our study where basal cell carcinomas accounted for 11.9% of all biopsies; squamous cell carcinoma was seen in 3.4%, malignant melanoma in 1.01%, Bowen's disease in 1.4% and eccrine poroma in 0.2%. The average age of subjects with basal cell carcinoma was approximately 66 years.…”

“…Since then, especially over the past few years, several studies have tried to document such a relationship. Many authors accept the rare coexistence of skin malignancy with seborrhoeic keratosis despite the fact that the latter is quite common in the general population 6 …”

“…Many authors accept the rare coexistence of skin malignancy with seborrhoeic keratosis despite the fact that the latter is quite common in the general population. 6 Evolution towards malignancy can lead to the appearance of malignant melanoma, 6,7 squamous cell carcinoma, [8][9][10] fig. 2 Histopathological picture of an adenoid basal cell carcinoma with overlying-adjacent seborrhoeic keratosis (haematoxylin and eosin, original magnification × 40).…”

“…2 Histopathological picture of an adenoid basal cell carcinoma with overlying-adjacent seborrhoeic keratosis (haematoxylin and eosin, original magnification × 40). 11 basal cell carcinoma, 6,[12][13][14] Bowen's disease, 15 intraepithelial epithelioma 16 and eccrine porocarcinoma. 17 These findings correspond generally with those of our study where some lesions with a clinical picture of seborrhoeic keratosis histopathologically proved to be basal or squamous cell carcinomas, actinic keratoses, malignant melanomas, lesions of Bowen's disease or eccrine poromas.…”

Case of seborrheic keratosis with underlying basal cell carcinoma suggesting a collision tumor

“…Usually manifested in middle‐aged individuals, it is a frequent focus of patient concern, not only in regards to cosmetics due to its often repugnant appearance, but also in reference to raising doubtful questions of its origin. Considering the epidemiological frequency of SK, reports of concurrent malignant tumors are rare, but previous and recent reports – especially the co‐manifestation of basal cell carcinomas (BCC) – have added to the ongoing debate of the possibility of the development of BCC from SK. We describe here a rare case of concomitant reticulated‐type SK and nodular‐type BCC in a patient, contributing to the unsettled controversy of whether they are of incidental co‐existence or represent a subtle malignant transformation.…”