Rare Variant: Primary Cutaneous Gamma/Delta T-cell Lymphoma

We've asked cutaneous lymphoma expert Dr. Barbara Pro to respond to the following questions regarding this rare variant of cutaneous T-cell lymphoma:
What is it?
How is this different from other types of cutaneous T-cell lymphoma?
What does this type of cutaneous lymphoma look like?
What are the treatment options?
What is the prognosis?