Squamous Eddies in Irritated Seborrheic Keratosis

Perioral Clonal Variant of Seborrheic Keratosis: Diagnostic Challenges

Seborrheic keratosis is the most common benign tumour of epithelial origin, whose incidence increases with the advance of age. The aetiology of SK is not completely known but exposure to UV radiation may be an associated factor. Most of the cases have a rough, verrucous appearance, slightly elevated, and black or brown in colour. They are usually painless but at times present with pus discharge or ulceration.

Lesions With an Epidermal Hyperplastic Pattern: Morphologic Clues in the Differential Diagnosis

In this report, we review the most common entities that show a epidermal hyperplastic pattern in the biopsy. These entities include inflammatory, reactive, infectious, hamartomatous, and tumoral conditions, each with a very different prognosis. Therefore, an approach based on the classic "patterns and clues" tools used in dermatopathology can bring a lot of information to the dermatopathologist or the general pathologist evaluating these lesions.

Pigmented tumor in the nostril

A 64-year-old man was noted to have a single pigmented lesion in the nostril of his nose. Clinical examination revealed a 5 mm nodular growth and brown lesion. With a presumed clinical diagnosis of malignant skin tumor, a biopsy was performed. The histological examination revealed the unexpected diagnosis of pigmented inverted follicular keratosis.

The inverted follicular keratosis is an uncommon benign lesion that is usually diagnosed histologically rather than clinically. It commonly simulates other proliferative skin lesions.

Are all seborrheic keratoses benign? Review of the typical lesion and its variants

BACKGROUND

Seborrheic keratosis (SK) is one of the more common benign epidermal neoplasms seen in adult and middle-aged patients.

OBJECTIVE

As little is written in the literature about the variants of SK, this article aims to categorize and discuss the different subtypes and their important associations.

METHODS

An in-depth literature search using OVID Medline and PubMed was conducted to classify the various subtypes of SK. Clinical variants were photographed and used to help document the subtypes. The pathology is described for each.

RESULTS

Six subtypes of SK were identified: dermatosis papulosa nigra, stucco keratosis, inverted follicular keratosis, large cell acanthoma, lichenoid keratosis, and flat seborrheic keratosis. Although the etiology and pathogenesis of SKs are still largely debatable, several underlying mechanisms and contributing factors have been identified. All subtypes represent benign lesions, and treatment is usually done for cosmetic reasons. Several of the subtypes may act as cutaneous markers for internal malignancy and should be monitored closely for any atypical changes.

CONCLUSION

Although all subtypes of SK are benign, their association with other malignant lesions and ability to serve as cutaneous markers of internal malignancy emphasize the importance of correctly identifying all variants.