case_images: PMC7739100_01
case_images: Clinical examined identified a 3 x 4 cm raised, indurated lesion with crusting, superficial ulceration and a serosanguinous discharge.
case_images: f1000research-8-20993-g0000.jpg
case_images: PMC7739100_01_f1000research-8-20993-g0000.jpg
case_images: f1
case_images: It was raised, indurated, crusted, demonstrated a sparsity of hairs on the surface, had superficial ulceration and exuded serosanguinous fluid when pressed ( Figure 1).
case_images: Microscopic images of the skin tumour.. (
  A) Squamous epithelium with trichilemmal keratinisation (x4 objective). (
  B-
  D) Epithelium with nuclear pleomorphism, mitoses and an infiltrative architecture (x20 objective).
case_images: f1000research-8-20993-g0001.jpg
case_images: PMC7739100_01_f1000research-8-20993-g0001.jpg
case_images: f2
case_images: Microscopic examination of the lesion identified rounded dermal lobules of squamous epithelium with trichilemmal keratinisation in keeping with a pre-existing pilar cyst ( Figure 2A). Areas with nuclear pleomorphism, mitoses and an infiltrative architecture were noted, and they retained trichilemmal keratinisation ( Figure 2B-D).