P. Ambrojo

Solitary keratoacanthoma : A self-healing proliferation that frequently becomes malignant

To discuss the relation between solitary keratoacanthoma (KA) and crateriform squamous cell carcinoma (cSCC), the clinical and histologic features of cutaneous crateriform squamous cell proliferations were studied. Two hundred twenty cases of wholly excised crateriform squamous cell proliferations were studied both clinically (age, sex, location, and duration) and histologically (hematoxylin-eosin–stained sections). For comparison, we studied 100 consecutive cases of wholly excised noncrateriform squamous cell carcinoma (ncSCC). One hundred forty-four of the 220 cases of crateriform squamous cell proliferations were histologically classified as KA. In 47 other cases, a relatively large area of the KA showed frank histologic and cytologic malignant transformation (mKA); this event could happen during every stage of the KA. Twenty-nine lesions were cSCCs without remnants of KA. The patients in the KA group were significantly younger (p = 0.000) than those in the other three groups. The ages of the patients in these three groups were not significantly different (p = 1.0). More KAs (16%) were located in areas that are not usually exposed to the sun than was the case with the other groups of neoplasms considered (2%, 3%, and 3%, respectively), and this difference was statistically significant (p = 0.001). Regarding the duration of the lesion, only the differences between KA and cSCC, KA and ncSCC, and mKA and ncSCC were statistically significant. Not every cutaneous crateriform squamous cell proliferation is a KA; in KA, the crater must be multilocular, the “lips” must be perforated, and the cornified contents do not usually project out of the “mouth.” At least a quarter of KAs undergo malignant transformation, which occurs more frequently in older patients and photoexposed areas. This transformation is a focal event and may happen at any stage of KA development. Consequently, a suspected KA must be wholly excised and studied in serial paraffin blocks so as to disclose any focus of malignant transformation.

Epidermotropic metastases from internal carcinomas.

Four cases of epidermotropically metastatic carcinoma are reported. One of them originated from a breast adenocarcinoma; in two other cases, the primary tumor was located in the large intestine; and. in the fourth case, the primary malignancy was a laryngeal squamous cell carcinoma. Clinically, the cutaneous metastases were nodular lesions and histologically, in addition to the involvement of the dermis by malignant cells, in three cases there was intraepidermal involvement by glandular structures. In the fourth case, the cutaneous metastatic tumor cells showed striking “folliculotropism.” We review the literature of epidermotropically metastatic carcinoma and discuss its differential diagnosis.

Cutaneous lymphangiectases after therapy for carcinoma of the cervix—a case with unusual clinical and histological features

Secondary lymphangioma (lymphangiectasis) has been reported as a consequence of lymphatic damage. No specific histological criteria can be used to differentiate primary lymphangioma circumscriptum from lymphangiectasis. We describe a woman who developed lymphangiectases on both non‐lymphoedcmatous upper thighs after hysterectomy and radiation therapy for carcinoma of the cervix.

Clear-Cell Syringoma

Clear-cell syringoma is a histologic variant of syringoma that is otherwise clinically indistinguishable from ordinary syringoma. This variant is formed by cells that have pale or clear cytoplasm as a

Angiolymphoid hyperplasia with eosinophilia limited to the vulva

A patient with angiolymphoid hyperplasia with eosinophilia is described. This is, to our knowledge, the first case report in which the lesions were located on the vulva.

Pseudo-Kaposi sarcoma induced by minor trauma in a patient with Klippel–Trenaunay–Weber syndrome

Arteriovenous malformations (AVM) are vascular anomalies containing a communication between an artery and a vein without an intervening capillary bed. 1 In 1990, Klippel and Trenaunay reported a patient with limb overgrowth, cutaneous angiomata and varicose veins. 2 In 1918, Parkes Weber mentioned the additional feature of AVM terming the condition‘hemangiectatic hypertrophy. 3 Most authors now consider both the Klippel Trenaunay syndrome and the syndrome of multiple congenital arteriovenous fistulae to be two forms of Parkes Webers hemangiectatic hypertrophy. 4

Trichilemmal cyst under a compound melanocytic nevus

Cystic dilatation of a hair follicle, folliculitis, abscess formation and epidermoid cysts are not infrequent findings in an intradermal melanocytic nevus. We herein report a trichilemmal cyst under a compound melanocytic nevus. To the best of our knowledge this association has not been previously reported.

Achromic verrucous large cell acanthoma.

Large cell acanthoma (LCA) is an epidermal neoplasm whose nature has been variously explained. Though frequently hyper‐pigmented, we describe for the first time an achromic case located on the dorsum of the right hand of a 83‐year‐old woman. This observation is largely inconsistent with one of the theories about the nature of this condition: that it is merely a solar lentigo with large nuclei of keratinocytes.

Carcinoma anexial microquístico de células claras

Resumen —El carcinoma anexial microquistico es una neoplasia infrecuente que muestra invasividad local. Se presenta un caso de carcinoma anexial microquistico en el dorso nasal de una mujer de 58 anos. Microscopicamente el tumor mostraba quistes corneos calcificados en la parte mas superficial de la neoplasia y estaba constituida principalmente por nidos y cordones de celulas claras que afectaban totalmente la dermis y el tejido celular subcutaneo e invadia el musculo esqueletico y los espacios perineurales. La estroma que rodeaba la neoplasia era desmoplasica y la atipia citologica era minima. La presencia de celulas claras se ha descrito ocasionalmente en el carcinoma anexial microquistico.