BACKGROUND
Keratoacanthoma (KA) is a common skin tumour in
dermatology. It manifests as a rapidly growing, well-differentiated,
squamoid lesion with a predilection for sun-exposed sites in the
elderly1. KA is composed of keratin-plugged,
cutaneous, crater-shaped nodules that arise spontaneously. Some KAs tend
to spontaneously involute, and they may grow to a size of 1–2 cm before
involuting2. However, owing to their tendency for
regression, KAs have been categorized as biologically benign tumours
with distinct pathophysiological mechanisms from those of malignant
cSCC1. Thus, rare cases of
distant metastasis purported to
originate from KA can be found in the literature1.
Here, we have reported the case of adjacent tissue skip metastasis of KA
on the nose.