2.4.3 Skin Pathology I Flashcards
What are the scientific terms for these?
Acquired melanocytic nevus
What are the characteristics of a congenital melanocytic nevus?
Id this feature of squamous cell carinoma
Keratin pearl
What are the terms for these skin lesions?
What are the microscopic terms?
ID this neoplasm
Basal cell carcinoma
What type of melanoma most frequently causes death?
Nodular melanoma - arises from a stem cell in the dermis
What is the phrase about moles throughout life?
Born without moles, die without moles
What are the ABCDEs of melanoma?
Assymetry
Border irregularity
Color variation
Diameter (>5 cm)
Evolving
If a person has a bunch of moles and one appears different, what is the phrase for identifying it as melanoma?
“Ugly duckling sign”
What type of epithelial neoplasm?
Seborrheic keratosis
Identify these findings found with nodular melanoma
Nodular melanomas usually demonstrate poor prognostic features such as ulceration (arrow) and microsatellitosis (circle). Microsatellitosis is defined as an aggregate of tumor cells more than 0.05 mm in diameter located in the reticular dermis, perivascular adventitium, or hypodermis and separated from the main body of invasive tumor by at least 0.3 mm of normal tissue. The high growth rate of this tumor is reflected in the signs of impending hemorrhagic necrosis (arrow) and the frequent mitotic division figures (arrows).
What type of mutation is associated with nodular MM?
RAS mutation
Identify these features of this epithelial neoplasm and the type of epithelial neoplasm
ID structures
What type of nevus is most commonly associated with melanoma?
The dermal nevus
Identify this skin lesion
Squamous cell carcinoma
Types of skin?
Left: Thin
RIght: Thick
Dependent on the size of the epidermis
What type of nevus?
Junctional Melanocytic Nevus
(Nevi of the epidermal compartment may be predominantly nested or predominantly lentiginous. Here we see melanocytic nevus within the epidermis and demonstrating a predominantly nested arrangement. (inset) A nest is arrowed in this inset. Nests are round to oval aggregates of melanocytes with a predilection for the tips of the rete ridges. Nesting is arbitrarily defined by at least 3 or 5 melanocytes depending upon who you ask. Note that the rete ridges are elongated and associated with periretal fibrosis and telangiectasias, some of the architectural features described in dysplastic nevi. Most epidermal melanocytic nevi will demonstrate these features. We will explore the concept of dysplastic nevi in greater detail later in this talk.)
What is the difference b/t the halos of melanocytes and kerationcytes?
Keratinocyte - halo goes to the nucleus
Melanocyte - halo goes around shrunken wisps of cytokeratin
What type of melanoma?
Nodular melanoma
Nodular melanoma manifests as an expansile nodule of malignant melanocytes that is centered in the dermis. Though there is usually involvement of the epidermis directly overlying the tumor, in some cases the tumor is spares the epidermis. These cases are often referred to as “dermal” melanoma, but they are simply one form of nodular melanoma in my opinion. The location of the growth center in the dermis and the existence of cases without epidermal involvement has led some to speculate the cell of origin lies in the dermis. This form of melanoma has the highest growth rate of all melanoma subtypes, though prognosis is similar to other subtypes of melanoma of comparable thickness. However, nodular melanomas are usually more than 1 mm in thickness at the time of diagnosis, and the prognosis of a given nodular melanoma is worse than that of other melanoma subtypes on a case-by-case basis if they are not segregated by thickness. Nodular melanomas often do not meet the clinical ABCD criteria. They may be amelanotic, well-circumscribed, and quite symmetric. Clinicians often do not even list melanoma in their differential, and I have seen several cases submitted as pyogenic granulomas. A history of recent onset, rapid growth, and bleeding should always warrant a biopsy.
Diagnose me.
This is an example of superficial spreading melanoma. Superficial spreading melanoma is often described as the most common subtype of melanoma. However, if one counts both in situ and invasive melanomas, then lentigo maligna is more common. Superficial spreading melanoma has a predilection for intermittently sun-exposed skin such as the extremities, and demonstrates a nested arrangement of obviously atypical melanocytes. Some experts have proposed origin from a melanocytic stem cell that resides in the epidermis, as all case show epidermal involvement.
Name the type of nevus
(Note the melanocytic cords)
Congenital melanocytic nevus
What is the most common type of melanoma among other ethnicities?
Acral lentiginous MM
ID this neoplasm
Basal cell carcinoma
What is the most common overall type of melanoma?
Superficial spreading melanoma
Identify the subtypes of melanoma
Identify this lesion
Solar lentigo
This microscopic section is indicative of what type of epithelial neoplasm?
Solar lentigo
What is the arrow pointing to? What are these found in?
Nest of melanocytes
in a Junctional nevus
ID layers
Identify these features of superficial spreading melanoma
Name this epithelial neoplasm
Seborrheic Keratosis
What type of epithelial neoplasm?
Actinic Keratosis
Identify these cell types
ID
