And with that, we'll get started.

Hello, my name is Jeff Gardner, and today I'm going to present the article, Differentiating Carotid Acanthoma from Squamous Cell Carcinoma in the Quest of the Holy Grail by P. Nagarajan, published in the Journal of Cutaneous Pathology in 2020.

The main focus of this article is, is there one immunohistochemical or cytogenetic marker to distinguish KAs or keratoacanthomas from SECs or squamous cell carcinomas? The big picture answer is no.

Thus, how do we determine this difference? Through clinical pathologic correlation and careful histologic examination.

First, let's kind of discuss the natural history of keratoacanthomas and the pathology of each.

KAs typically occur on sun-exposed skin and progress through three phases, a proliferative or early phase, a stabilized or well-developed phase, and a regressive or late phase.

Early lesions are characterized by invaginations of acanthotic squamous epithelium with infundibular differentiation.

Therefore, cytologic observations gain importance in the diagnosis of sebaceous neoplasms in the setting of well-circumscribed architecture, and cytologic similarities found in sebaceous adenoma and sebaceous carcinoma could actually indicate a close biologic relationship between the two neoplasms.

Hi, my name is Jeff Gardner, and my article was on two histopathologic patterns of well-differentiated extraocular sebaceous carcinoma.

So a little bit of background, sebaceous carcinoma is kind of an uncommon adnexal malignancy, kind of broken down by the location.

The majority, about 75% being ocular and about 25% being extraocular.

It's also broken down by its degree of differentiation being well, moderate, and poor, and then also by its growth pattern.

In this article, the authors bring to the attention that well-differentiated extraocular sebaceous carcinoma had two histopathologic patterns, the first being secretory, or those that maintain true sebaceous glands architecture with holocrine secretion, versus non-secretory, which is typical of what is presented in review articles and textbook descriptions.

So kind of the study of this paper or the objective was to determine the clinical pathologic significance of these two patterns described.

To kind of summarize,