Related Experiment Video
Updated: Mar 20, 2026
Author Spotlight: Anterior HR-OCT as a Non-Invasive Tool for Characterizing Ocular Surface Squamous Neoplasia
Published on: August 9, 2024
Squamous Cell Carcinoma In Situ Overlying Merkel Cell Carcinoma
Maria A McGowan1, Matthew F Helm2, Michelle B Tarbox2
1Mercer University School of Medicine, Savannah, GA, USA mcgowan_ma@med.mercer.edu.
Background:
Merkel cell carcinoma (MCC) is a rare and aggressive cutaneous neoplasm that has exhibited an exponential increase in incidence in the past 3 decades. Combined MCC and cutaneous squamous cell carcinoma (SCC/MCC) is an uncommon variant of MCC that exhibits worse prognosis than pure MCC.
Objective:
To describe the clinical presentation, dermoscopy, and histology of an unusual subtype of combined SCC/MCC.
Methods And Results:
A 73-year-old white woman presented with an ulcerated and violaceous 10-mm plaque on her right jawline that had been present for 2 to 3 months. On dermoscopy, the lesion was predominantly milky pink to red with peripheral crusting and large-caliber polymorphous vessels. Histology revealed SCC in situ above and adjacent to MCC. The tumor was excised with clear margins, and sentinel lymph node scintography was negative for nodal involvement.
Related Concept Videos
01:30Skin Cancer
Basal Cell Carcinoma (BCC): BCC is the most common type of skin cancer, accounting for about 80% of cases. It typically develops in...
01:24Cells of the Epidermis
The cells in all these layers except the stratum basale are called keratinocytes, a type of cell that manufactures and stores the protein keratin. The keratinocytes in the stratum corneum are dead and regularly slough away, being replaced by cells from...
01:11Papillary Dermis
The dermis might be considered the "core" of the integumentary system, as distinct from the epidermis and hypodermis. It contains blood and lymph vessels, nerves, and other structures, such as hair follicles and sweat glands. The dermis is made of two layers of connective tissue that comprise an interconnected mesh of elastin and collagenous fibers, produced by fibroblasts.
Papillary Layer
The papillary layer is made of loose, areolar connective tissue, which means the collagen...