Malignant lesions Flashcards
What is melanoma?
Malignant neoplasms of melanocytic origin that arises from a benign melanocytic lesion or de novo melanocytes
What is considered a major causative factor of melanoma?
UV radiation
Is acute sun damage or chronic sun exposure a greater causative factor in melanoma?
acute sun damage
What are risk factors of melanoma?
Light skin and hair
tendency to burn easily
history of painful or blistering sunburns during childhood
indoor occupation
hx of dysplastic congenital nevus
How common is melanoma among skin cancers?
3rd most common
How fatal is melanoma compared to other skin cancers?
most deaths due to skin cancer caused by melanoma
A high proportion of melanomas posses mutations in what gene?
BRAF gene
What pathway is the BRAF gene involved in?
Ras-Raf-ERK signaling pathway
What are the ABCDE clinical features of melanoma?
Asymmetry
Border Irregularity
Color Variation
Diameter greater than 6mm
Evolving
What is the most common form of melanoma?
superficial spreading melanoma
Where do nodular melanomas most commonly occur?
Head and neck
How do nodular melanoma lesions appear?
deeply pigmented exophytic lesion
What is the precursor of lentigo maligna melanoma?
precursor lesion is lentigo maligna or Hutchinson’s freckle
Lentigo maligna melanoma is almost exclusively found in what population?
Sun exposed skin of fair complexioned older adults particularly in the mid facial region
Lentigo melanoma histologically represents what kind of melanoma?
melanoma in situ in a purely radial growth phase
What is the most common form of melanoma in african americans?
Acral lentiginous melanoma
What is the most common oral melanoma?
Acral lentiginous melanoma
How is superfical spreading melanoma histopathologically characterized during its radial growth phase?
Characterized by spread of atypical melanocytes along the basilar portion of the epidermis.
Individual melanocytes will also invade the higher levels of the epithelium (normally only in stratum basale)
How is acral lentiginous melanoma histopathologically characterized during its radial growth phase?
numerous atypical melanocytes in the basilar portion of the epithelium
Melanocyte invasion into the superficial lamina propria
What factor is important in determining the prognosis of melanoma?
Depth of the invasion is an important component of the hisopathologic evaluation
What is the Clark System of Measurement?
Assigns a level to the lesion that depends on the deepest anatomic cutaneous region invaded by the tumor.
What is the Breslow Classification?
More accurate
based on the measurement of the distance from the top of the granular cell layers to the deepest part
What area of melanoma has the worst prognosis?
BANS
Back
posterior Arm
posterior and lateral Neck
Scalp
Is overall prognosis of melanoma bad or good?
extremely poor
