Unna's and Miescher's nevi: two different types of intradermal nevus: hypothesis concerning their histogenesis.

In 1991, we tentatively introduced the classification of Ackerman and Magana-García for acquired melanocytic nevi in our laboratory. We soon realized that every acquired intradermal melanocytic nevus might be easily classified into either Unna's or Miescher's patterns and that this classification had both clinical implications and significant histological differences. The decisive discriminative feature between Unna's and Miescher's nevi is that Unna's nevus is an almost purely adventitial lesion confined to expanded papillary dermis and, many times, to the perifollicular dermis too. In Miescher's nevus melanocytes diffusely infiltrate both adventitial and reticular dermis in a wedge-shaped pattern. With these concepts in mind, every acquired intradermal melanocytic nevus can be easily classified as either Unna's or Miescher's. We studied 751 acquired melanocytic nevi; 458 (61%) of them were intradermal; of these, 234 were Unna's nevi and 224 were Miescher's nevi. Eighty- three per cent of the nevi from the head and neck were intradermal nevi, whereas on the trunk and limbs junction and compound nevi were the most frequent (56%). When intradermal nevi were divided into Unna's and Miescher's patterns, it resulted that 91% of Miescher's nevi located on the face and 94% of intradermal nevi on the face were Miescher's nevi. In contradistinction, 87% of the Unna's nevi located on the neck, trunk, and limbs, and 96% of intradermal nevi from these locations were Unna's nevi. Only on the scalp was there no clear predominance of one type of intradermal nevus. A series of other histological characteristics were significantly predominant (P = 0.000) in either Unna's or Miescher's nevi. Unna's nevi had more: junctional nests above the intradermal component (40% versus 20%), a radial pattern of intradermal nests (38% versus 0%), vascular-like clefts lined by nevus cells (48% versus 4%), and in depth maturation (94% versus 0%). Miescher's nevi had more: pilosebaceous follicles within the nevus (100% versus 51%), subnevis folliculitis (12% versus 1%), large isolated melanocytes along the basal epidermal layer (47% versus 11%), multinucleated nevocytes (89% versus 44%), and adipocytes within the nevus (53% versus 11%). In conclusion, Unna's and Miescher's nevi are 2 subsets of acquired melanocytic nevus with clinical implications and significant histological differences. A histogenetic hypothesis is proposed on the basis of their histological structure.

Aspergillus aortitis after cardiac surgery.

OBJECTIVES: The aim of this study was to describe the clinical characteristics of Aspergillus aortitis in a small series of consecutive patients. BACKGROUND: Aspergillus infection of the ascending aorta after cardiopulmonary bypass surgery has rarely been reported and has always resulted in death. METHODS: Aspergillus aortitis was confirmed by pathologic and microbiologic analysis in eight men (61 +/- 8 years) of 9,375 consecutive patients who underwent cardiac surgery between 1975 and 2000. RESULTS: Patients presented with Aspergillus aortitis after aortic valve replacement (n = 5), coronary revascularization (n = 2), or both (n = 1). Initial symptoms appeared between the immediate postoperative period and up to two years after surgery. All patients had prolonged fever. Ante-mortem diagnosis was established in only three patients for whom transthoracic echocardiography was suggestive of aortic pseudoaneurysm and was confirmed by thoracic computed tomography or aortography. All patients had negative peripheral blood cultures. Seven patients died at short-term follow-up, and the one surviving patient was promptly treated by surgery and antifungal drugs. Pathologic examination confirmed Aspergillus aortitis with multi-organ dissemination without heart involvement in all patients except for two, in whom aortic valve endocarditis was found. Fungal cultures confirmed the presence of Aspergillus fumigatus in all patients. CONCLUSIONS: Aspergillus aortitis is typically found after aortic valve or coronary surgery. It commonly leads to lethal multi-organ dissemination without involvement of the intracardiac structure. This entity should be considered in patients with persistent fever and negative blood cultures after open-heart surgery involving significant aortic wall damage, irrespective of the postoperative period.

Multinodular pilomatrixoma.

A hard deep nodule, 6 x 3 mm in size, was excised from the cheek of a 12-year-old girl. The histological sections showed a multinodular cyst-like proliferation, each nodule showing the typical structure and cytology of pilomatrixoma. A comparison is made between this case and the budding phenomenon that has been described in isthmus-catagen (tricholemmal) cyst.

Variaciones cualitativas y cuantitativas de la capa córnea epidérmica: su utilidad diagnóstica / Cualitative and quantitative variations of the epidermal horny layer: their diagnostic usefulness

Introducción: en 1978, Ackerman añadió a los tradicionales términos de hiperqueratosis ortoqueratósica y paraqueratósica tres variedades de la primera: laxa, compacta y laminar. Método: en este artículo redefinimos y matizamos tales términos llamando la atención sobre un aspecto no estudiado anteriormente: la apetencia tintorial de cada una de esas variedades de capa córnea. Resultados: la capa córnea laxa, normal o hiperqueratósica es siempre basófila. La córnea compacta, normal, hiperqueratósica o heterotópica muestra dos variantes, una basófila y otra eosinófila. La córnea laminar es siempre eosinófila igual que la córnea paraqueratósica. Conclusiones: tomando como base la apetencia tintorial de la capa córnea (basófila o eosinófila) y su estructura (laxa, compacta, laminar o paraqueratósica), se propone un algoritmo con el que efectuar una descripción objetiva de la capa córnea epidérmica de cada biopsia. Se discute la significación de cada una de esas variedades atendiendo a la localización del proceso biopsiado (AU)