Pathology of non-pigmented skin lesions Flashcards
What is Leser Trelat sign?
Explosive eruption of many seborrhoeic keratoses as part of a paraneoplastic syndrome
What pathological feature is often seen in seborrhoeic keratoses?
“Horn” cysts- epidermal cysts filled with keratin
What are the three main subtypes of basal cell carcinoma?
Nodular, superficial and infiltrative
What pathological feature is often seen in nodular BCC?
Peripheral palisading of cells
Which type of BCC is most challenging?
Infiltrative- may infiltrate widely and deeply with unclear margins, making resection difficult
What is Bowen’s disease? Where are the lesions often seen?
SCC in-situ, scaly itchy plaques often seen on women’s legs
Where is SCC most often seen?
In elderly people, face, ears, dorsal hands, with history of sun exposure
What are the adverse prognostic indicators in SCC?
Thickness >4mm Lymphatic or vascular spread Perineural spread Specific sites e.g. scalp, ear, nose
How does SCC appear histologically?
Pleomorphic cells, atypical mitoses, keratin “pearls” Poorly differentiated tumours have less keratin, more atypia and more mitoses
Seborrhoeic keratoses
Nodular BCC
Nodular BCC
What feature of nodular BCC does this show?
Peripheral palisading
What is this lesion and what is it a precursor of?
Bowen’s disease plaque
SCC
What are these lesions and what are they a precursor of?
Actinic keratoses
Invasive SCC
Squamous cell carcinoma
What features are visible on this slide and what is the diagnosis?
Cellular atypia, atypical mitoses, keratin pearls
SCC
