Keratoacanthoma with Glandular Proliferation

A case of keratoacanthoma (KA) with glandular proliferation was reported. The tumor was a firm, dome-shaped, elevated nodule on the cheek of an 82-year-old Japanese male. Generally, the tumor showed the typical histopathological features of KA; slight nuclear atypia and mitotic figures were present in a cup-shaped proliferation of keratinocytes and, in the center of the lesion, a keratin-filled crater with nests of dyskeratotic and acantholytic cells was seen. In the bottom of the lesion, a glandular structure forming branching, thin lumina was observed. The epithelium of the lumina was made up of two or more layers of columnar or cuboidal cells without keratinization. Tall columnar cells with oval nuclei were located in the luminal row and small cuboidal cells with round nuclei and scanty cytoplasm were in the outer layer. Immunohistochemical staining revealed that only the glandular structure was carcinoembryonic antigen positive. Lectin binding patterns observed in the glandular proliferation were similar to those reported for the apocrine gland. KA sometimes exhibits an adenoid structure in its lesion because of acantholytic changes. However, KA associated with true glandular proliferation has not been reported as far as we know, and our case is the first reported one. KA is thought to be a tumor of follicular origin, and the glandular proliferation observed in the present case seemed to have certain characteristics that suggest its apocrine origin.     

Keratoacanthoma

We give a brief review concerning morphogenesis, growth pattern, as well as clinical and histopathological definition of keratoacanthoma. The treatment of choice is excision of the tumor and postsurgical histological verification.     

Keratoacanthoma centrifugum marginatum

A case of 38-year-old male with multiple keratoacanthoma centrifugum marginatum is reported. Clinical presentation was in the form of multiple, firm, non-tender skin coloured nodules of variable sizes. Diagnosis was confirmed by the histopathological examination. The case is being reported because it is a rare variant of keratoacanthoma.     

Keratoacanthoma centrifugum marginatum

Keratoacanthoma centrifugum marginatum (KCM) is a rare distinct variant of keratoacanthoma. Based on three personal observations and a review of the literature, the authors describe the clinical and histological features of this neoplasm. Clinically KCM is characterized by the lack of a tendency for spontaneous remission and by continuous centrifugal spread. Histologically there is a subclinical, iceberg-like growth pattern. Like keratoacanthoma, KCM is a highly differentiated, biologically benign, non-metastasizing tumour. The treatment of choice is early excision of the tumour.     

Keratoacanthoma and multiple carcinomas

A case of keratoacanthoma, preceding four primary malignant tumours without metastasis, is presented. Two similar cases from the literature with two and three multiple primary carcinomas, are reviewed. They all have the following findings in common: (1) keratoacanthoma, (2) adenocarcinoma of the colon, (3) additional primary malignant tumour or tumours, and (4) absent or delayed metastasis.     

Keratoacanthoma centrifugum marginatum.

A keratoacanthoma centrifugum marginatum measured 20 X 14 cm at the time of surgical intervention. This lesion is characterized by continuing peripheral extention and central healing. Attention is drawn to the occurrence in the healing edge of a distinctive type of individual cell necrosis, which has been described by others in the more usual forms of keratoacanthoma. The findings are of interest, since this same mode of cellular death has recently been shown to be involved in the regression of various tissues, normal as well as abnormal.     

Chromoblastomycosis Can Mimic Keratoacanthoma

A 59-year-old white man presented to the Dermatology Clinic at the University of Texas Medical Branch with ti verrucous nodule on the right forearm. The patient was a retired woodworker. He had polytiiyositis with pulmonary fibrosis for 5 years. Prednisone and mcthotrexate were required to control his disease.
A crusted verrucous nodule 2.5 by 2.5 cm in diameter with adjacent similar-sized atrophic scars were present on the extensor surface of the right forearm (Fig. 1). This particular nodule had been present for 2 years, and its growth was characterized by a rapid onset with progressive enlargement and intermittent partial regression. The adjacent scars represented similar lesions that had spontaneously regressed. Although the patient had not worked since his illness began, he continued to actively pursue woodworking as a hobby.
Histologic sections of the excised nodule revealed massive pseudoepitheliomatous hyperplasia with prominent hyper-keratosis. Intraepidermal microabscesses were numerous and a suppurative neutropbilic infiltrate with scattered foreign body type multinucleated giant cells was present in the dermis (Fig. 2). At higher magnification, numerous light brown yeasts, approximately 10 μm in diameter (Fig. 3) were noted both within tbe giant cells and free within the dermis. Chains of yeast cells were common. These histologic findings are diagnostic of chromoblastomycosis.³