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Histopathological diagnosis of epithelial crateriform tumors: Keratoacanthoma and other epithelial crateriform tumors
Author(s) -
Ogita Azusa,
Ansai Shinichi,
Misago Noriyuki,
Anan Takashi,
Fukumoto Takaya,
Saeki Hidehisa
Publication year - 2016
Publication title -
the journal of dermatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 65
eISSN - 1346-8138
pISSN - 0385-2407
DOI - 10.1111/1346-8138.13390
Subject(s) - keratoacanthoma , seborrheic keratosis , pathology , malignancy , medicine , incidence (geometry) , keratosis , trichoepithelioma , lesion , malignant transformation , hyperkeratosis , dermatology , basal cell , basal cell carcinoma , physics , optics
Keratoacanthoma ( KA ) is a unique and distinct clinicopathological entity, although there is often confusion regarding its differentiation from other types of crateriform tumors. In this study, the clinicopathological features of 380 epidermal crateriform tumors with a central keratin plug were re‐examined and the tumors were histologically classified into seven types: (i) crateriform verruca; (ii) crateriform seborrheic keratosis; (iii) KA ; (iv) KA with a conventional squamous cell carcinoma ( SCC ) component ( KA ‐like SCC and KA with malignant transformation); (v) crateriform Bowen's disease; (vi) crateriform SCC arising from solar keratosis; and (vii) crater form of infundibular SCC . Our study proved that incidence of SCC developing in KA lesions was 17.4%. The incidence rate differed depending on a patient's ages: 8.3% in patients less than 70 years of age and 24.3% in those aged 70 years and older. Nearly all of the malignant crateriform neoplasms (94.7%) occurred on sun‐exposed areas. Lesions on the face included 138 KA (59.5%), 65 malignant crateriform neoplasms (28%) and 29 benign crateriform neoplasms (12.5%). We conclude that KA is not a variant of SCC , but a benign and frequently regressing proliferative lesion or borderline neoplasm, although there is the potential for SCC to arise within KA . Because the incidence of SCC developed in KA lesions and the incidence of other malignant crateriform neoplasms are higher in patients aged 70 years and older, KA ‐like lesions on sun‐exposed areas over 70 should be assessed carefully in consideration of the potential risk of malignancy.