IntroductIon Beckers et al. (2006) published intriguing results, obtained in the rat fear conditioning paradigm, challenging classical associativist theories of learning. One of the main findings of Beckers et al. (2006) is that what they called subadditive pretraining abolished the expression of blocking (see Table 1; Figure 1), an effect that Beckers et al. (2005) had previously demonstrated ...

Becker naevus syndrome is a rare epidermal naevus syndrome defined by the co-occurrence of a Becker naevus with various cutaneous, muscular and skeletal anomalies. In the majority of cases, abnormalities exclusively consist of ipsilateral hypoplasia of the breast, areola and/or nipple in addition to the naevus. Here, we report on a 42-year-old woman with an extensive Becker naevus reaching from...

In order to determine dermoscopic parameters, a case-control test set of naevus-associated melanomas vs de novo melanomas paired by Breslow thickness and histopathological subtype was analysed by 2 blinded experienced dermoscopists, according to presence of naevus, pattern analysis and ABCD dermoscopy score. The ability to identify naevus-associated melanomas by pattern analysis was low for bot...

Les naevus congénitaux surviennent chez environ 1% des nouveaunés. La classification la plus utilisée est basée sur leur taille; on parle de naevus congénital de petite taille quand le plus grand diamètre est inférieur à 1,5cm, de naevus de taille intermédiaire pour ceux compris entre 1,5 et 19,9cm, de naevus large quand le diamètre est supérieur à 20cm et de naevus géant quand la taille est su...

The pathologist often has a difficult task in evaluating melanocytic lesions. For lesions involving the face the consequences of misdiagnosis are compounded for both cosmetic and therapeutic reasons. In this article, the pathological features of common and uncommon benign and malignant melanocytic lesions are reviewed and pitfalls in their diagnosis are highlighted. Benign lesions resembling me...

BACKGROUND The origin of melanoma has always been a debated subject, as well as the role of adjacent melanocytic naevi. Epidemiological and histopathological studies point to melanomas arising either de novo or from a naevus. OBJECTIVES To evaluate the presence of mutations in genes from well-known melanomagenesis pathways in a large series of naevus-associated melanomas. MATERIALS AND METH...

Apocrine skin carcinoma is an aggressive cutaneous tumour. We report a case of apocrine carcinoma developing in a naevus sebaceous of scalp in a 45 years old male. Malignant transformation of Naevus sebaceous is a rare complication usually found in elderly patients. Most of these tumours are basal cell carcinoma or squamous cell carcinoma. Only few cases of apocrine carcinoma on naevus sebaceou...

Sir, Becker's naevus or Becker's melanosis is a relatively common disorder, which appears as a hyperpigmented, hypertrichotic patch located mainly on the trunk (1). Becker's naevus has been associated with various soft tissue and bony structural anomalies, such as hypoplasia of the ipsilateral breast, pectoralis major muscle, leg, arm and contralateral breast, spina bi®da, and pectus carinatum ...

Sir, Becker's naevus is a variant of epidermal naevus characterized by a single, hyperpigmented macule with increased hair growth on the shoulder, chest or scapular regions, but any other area can be involved (1). It is most common in men and classically observed during adolescence, but can be seen from birth and can also be familial. Histopathologically, there may be mild acanthosis and papill...

Beckers, Miller, De Houwer, and Urushihara (2006) described the results of 3 blocking experiments conducted with rats. Beckers et al. concluded that the results of these experiments cannot be accounted for with existing theories of associative learning, and argued, instead, that the results were a consequence of the rats engaging in a process akin to effortful reasoning. Simulations of the Resc...