Vertical growth has higher rate of nodal involvement and poorer outcome.
Typical location is glans penis, coronal sulcus or prepuce (distal penis) (image A).
For usual type, keratinization related to differentiation (mostly have obvious keratin – well to moderately differentatied) (image B).
Other types include pseudohyperplastic (associated with lichen sclerosus, low grade in elderly), warty (condylomatous, with koilocytes) (image C), verrucous (see later), papillary, basaloid (non-keratinizing small to intermediate cells), sarcomatoid (spindle cell), cuniculatum (verrucous with deep burrowing and cobblestoning) and mixed.
p16 immunostain is a marker for high risk HPV and SCC with basaloid features and high grade nonbasaloid are likely to be more positive than low grade keratinizing SCC (image D).
Metastases: SCCa of the penis tends to be locally invasive but may metastasize to inguinal lymph nodes; hematogenous spread is relatively uncommon, despite the rich vascularity of the corpora cavernosa.
Verrucous and psedohyperplastic SCCs have low risk for nodal metastasis.
Basaloid, sarcomatoid, adenosquamous, and poorly differentiated usual SCCs have higher risk for nodal involvement.