Keratoacanthoma en plaque/nodule: A brief report of the clinicopathological features of five cases.
Keratoacanthoma (KA) is characterized by exoendophytic growth with a central keratin-filled crater, representing the crateriform architecture. We herein report five rare cases of KA without a central keratin-filled crater. These KA cases histopathologically showed that one or a few infundibular structures/isthmic lobules had their own open keratotic pores on the surface without a common merged keratotic plug/horn, clinically representing verrucous (keratotic) plaque/nodule, namely, "KA en plaque/nodule". KA rarely but on occasion does show verrucous plaque (or nodular) lesions without a central keratin-filled crater, as the notion that KA invariably shows crateriform architecture is nonsensical.
Division of Dermatology, Nakao Clinic, Saga, Japan.
Noriyuki
N
Misago
Division of Dermatology and Dermatopathology, Nippon Medical School Musashi Kosugi Hospital, Kawasaki, Japan.
Shin-Ichi
SI
Ansai
Sapporo Dermatopathology Institute, Sapporo, Japan.
Takaya
T
Fukumoto
Sapporo Dermatopathology Institute, Sapporo, Japan.
Takashi
T
Anan
Division of Dermatology, Nakao Clinic, Saga, Japan.
Tomokazu
T
Nakao
D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D015603:Keratinocytes / Q000473:pathology*; D007636:Keratoacanthoma / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D012867:Skin / Q000166:cytology / Q000473:pathology*
infundibular squamous cell carcinoma; keratoacanthoma en plaque/nodule; seborrheic keratosis; verruca vulgaris; verrucous carcinoma