Pathophysiology + Managment
This is the most common cause of Merkel cell carcinoma (MCC) and is a key factor in its pathogenesis.
What is the Merkel cell polyomavirus (MCPyV)?
This type of skin cancer commonly originates from a chronic non-healing ulcer or a burn scar?
What is squamous cell carcinoma?
This is the most significant environmental risk factor for most skin cancers.
Merkel cells are a type of neuroendocrine cell found in this specific layer of the skin.
What is the stratum basale?
This staging procedure is performed on all patients with clinically localized Merkel cell carcinoma due to the high risk of subclinical metastasis to regional lymph nodes.
What is sentinel lymph node biopsy?
This is the 5-year survival rate of Merkel Cell Carcinoma.
What is 60%?
This growth phase of melanoma indicates poor prognosis.
Vertical Growth
HIV or organ transplant patients are at a higher risk of Merkel Cell carcinoma or SCC because...
What is immunosuppression?
Merkel cells are closely associated with nerve endings and function as this type of receptor.
According to the AJCC staging system, a T1 primary tumor is classified as having a maximum dimension of this size or less.
What is less than or equal to 2 cm?
This type of Merkel cell carcinoma is driven by a high mutational burden, often due to chronic UV exposure.
What is virus negative Merkel Cell Carcinoma?
This type of skin cancer has a characteristic histology described as "nests of basaloid cells with a palisading arrangement at the periphery".
What is basal cell carcinoma?
This is an inherited syndrome in which an individual has multiple atypical nevi; the syndrome is often associated with an increased risk of melanoma.
What is dysplastic nevus syndrome?
Merkel cells are most densely located in areas of the body with a high degree of tactile sensitivity, such as the fingertips and this other area.
Or: palms, soles of feet, hard and soft palate
The definitive diagnosis of Merkel cell carcinoma is established by this type of tissue sampling, which is then sent for both histopathologic and immunohistochemical evaluation.
What is an incisional biopsy? (will accept punch or excisional biopsy)
A viral oncoprotein from the Merkel cell polyomavirus binds to and inactivates..... (2 things)
What are Rb1 and p53?
This type of skin cancer is described as "invasive nests of keratinocytes with keratin pearls and intercellular bridges" on histology.
What is squamous cell carcinoma?
This is a hereditary condition characterized by an extreme sensitivity to UV light, as it is caused by a genetic defect in the DNA repair mechanisms that fix UV-induced damage.
While similar to other mechanoreceptors, Merkel cells are unique because they are the only type to release this neurotransmitter to communicate with their associated sensory neuron.
What is serotonin?
This is the key immunohistochemical marker used to identify Merkel cell carcinoma, often showing a specific paranuclear dot-like staining pattern.
What is CK20?
A pathologist examining a biopsy of Merkel cell carcinoma would be likely see these characteristic cells, which have scant cytoplasm and a high nuclear-to-cytoplasmic ratio.
What are small, round, blue cells?
The presence of a BRAF mutation is a common finding in many melanomas. This mutation leads to the activation of which downstream pathway, promoting cell proliferation and survival?
MEK/ERK
Carriers of this gene mutation are at an increased risk of melanoma.
What is BRCA mutation?
Merkel cells are classified as slowly-adapting receptors, which means they fire continuously in response to this type of stimulus.
What is continuous pressure?
This neural cell adhesion molecule is expressed on the surface of neuroendocrine cells. It is often used to confirm a diagnosis of Merkel Cell.
What is CD56?