Circumscribed Palmar or Plantar Hypokeratosis

Abstract

Circumscribed palmar or plantar hypokeratosis is a new entity recently described by Perez et al in 2002. It seems to be underdiagnosed or clinically it is often misdiagnosed as Bowen's disease or porokeratosis. Obviously the number of case reports of circumscribed palmar or plantar hypokeratosis has increased since the first publication by Perez et al.The histopathological hallmarks of this condition are a stair-like configuration with an abrupt thinning of the stratum corneum from uninvolved to involved skin with a central hypokeratotic area. There are no atypical keratinocytes or cornoid lamellation. We describe two new patients with circumscribed palmar hypokeratosis. In one case there were additional histopathological features including the loss of granular cell layer in the center of the lesion and an overlying compact thin parakeratotic layer.

Circumscribed palmar hypokeratosis: Successful treatment with fluorouracil cream

“…In a few patients, repeated trauma was reported to play a role in the pathogenesis 3,7. However, most patients, including the one in the present study, cannot recall this,1,2,8 and there is no explanation as to why the majority of lesions do not tend to heal spontaneously. Pérez et al1 considered that the disease might result from a clone of abnormal keratocytes, but in view of its benign behavior, favored an epidermal malformation.…”

“…In addition, parakeratosis is a feature which has been reported in other publications as well,3,8,11,12 but has not been present in the cases of the original series1 and other reports,5,8 possibly pointing towards different evolutionary stages,8 malignant transformation,11 or different diseases. Parakeratosis per se is a nonspecific finding, but together with the presence of a fainter stained epidermis, hypogranulosis, and dilated vessels in the papillary dermis, might point towards an underlying squamous cell carcinoma in situ presenting as CPH.…”

Premalignant Circumscribed Palmar Hypokeratosis: A New Form of Circumscribed Palmar Hypokeratosis? Case Report and Literature Review

“…CPH is a dermatosis of unknown origin, first reported in 2002 [1], of which 47 cases (including the present one) have so far been reported [2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26]. In our dermatopathology practice we have diagnosed CPH in 3 additional patients during the 7 last years [unpubl.…”

“…The underlying dermis is unremarkable. Some variations or additional features to this aspect have been reported, including a thin layer of parakeratosis [8,10,11], hypergranulosis [11,18], epidermal hyperplasia [11,12,18], a mild dermal inflammatory infiltrate [11], spongiosis [18] and dermal elastosis [1]. …”

“…However, treatment is disappointing. Local steroids, retinoids and keratolytics are usually ineffective [3,8,10,17,18]. Remissions have occasionally been achieved with local applications of calcipotriene [1,9], cryotherapy [17] and photodynamic therapy [20].…”