Giant verrucous porokeratosis of Mibelli mimicking psoriasis in a patient with psoriasis

Porokeratosis of Mibelli is a disorder of epidermal keratinization characterized by annular plaques with an atrophic center surrounded by a keratotic wall. We report a case of a giant verrucous porokeratosis of Mibelli mimicking psoriasis that developed in a patient with psoriasis and therefore went unrecognized for a long time. Histologically the lesion combined features of porokeratosis at the periphery and of psoriasis at its center, a picture recently described as "psoriasis encircled by porokeratosis." The possible pathogenetic relationship between psoriasis and the development of porokeratosis is also discussed.     

Disseminated giant porokeratosis and porokeratosis of Mibelli in Bankura and Bardhaman districts,West Bengal,India

Porokeratosis of Mibelli (PM) is a rare genodermatosis. It is caused by proliferation of abnormal clones of epidermal cells in response to several stimuli, the most important of which is sunlight. Giant porokeratosis is thought to be a variant of PM. We report two cases of disseminated PM and one case of disseminated giant porokeratosis from the Bankura and Bardhaman districts of West Bengal in India; presenting to a single observer in the summer of 2012. Interestingly we have noted that the majority of cases of porokeratosis in India have been reported from West Bengal. Few patients with a single lesion of giant porokeratosis have been reported in world literature. As far as we know, this is the first case report of disseminated giant porokeratosis in world literature.     

Porokeratosis on the scrotum: two cases

Porokeratosis is a group of hereditary or acquired disorders of epidermal keratinization, characterized by keratotic lesions with an atrophic center and a prominent peripheral ridge. At least seven clinical variants have been identified: the plaque type, disseminated superficial porokeratosis, disseminated superficial actinic porokeratosis, linear porokeratosis, giant porokeratosis, porokeratosis plantaris palmaris et disseminate, and punctuate porokeratosis. Genital porokeratosis is a rare condition even in disseminated forms. We described two male patients who had porokeratosis only affecting the scrotum. The patients were treated by surgical excision under local anesthesia. One‐year follow‐up revealed no sign of recurrences and malignant changes.     

A case of giant porokeratosis with vestiges of a cornoid lamella

We report a case of giant porokeratosis combined with ulcerative squamous cell carcinoma. In our patient, we biopsied the skin, including the edge of the skin lesion, four times until we obtained histologic proof of a cornoid lamella. After we had established the diagnosis, we totally excised the affected skin including a 10-mm safety margin, because such lesions tend to develop into skin cancer. We reconstructed the excised area using a skin graft. After the operation, we took 13 samples of skin (seven from the lower leg and six from the sole of the foot) from the edge of the main lesion, including a putative cornoid lamella. Five of the six samples from the sole and one of the seven from the lower leg were demonstrated histologically to include a cornoid lamella. Our results suggest that skin biopsies should be taken from various sites at the edge of a giant porokeratotic lesion and in particular from the prominent ridge to prove the presence of a cornoid lamella. Shallow keratin-filled invaginations and underlying squamous cells with eosinophilic cytoplasm were observed at the edge of the lesion on the lower thigh, which might suggest a diagnosis of porokeratosis with an incomplete cornoid lamella if porokeratosis was strongly suspected from the patient's clinical features. Better recognition of giant porokeratosis is required, so that an earlier diagnosis can be made and appropriate therapy initiated in a timely manner.     

Coexistence of disseminated superficial and giant porokeratosis of Mibelli with squamous cell carcinoma

Porokeratosis of Mibelli is a genetic disease transmitted as an autosomal dominant trait. The giant type of porokeratosis is a relatively rare entity and is associated with an increased risk of malignancy. The aim of this article is to present this rare case of giant porokeratosis associated with squamous cell carcinoma.     

Immunohistochemical Detection of p53 Tumor Suppressor Protein in Porokeratosis

We examined 9 Japanese cases of porokeratosis (4 of the plaque type, 2 of disseminated superficial actinic porokeratosis, 2 of disseminated superficial porokeratosis, and one of giant porokeratosis) for the expression of p53 tumor suppressor protein immunohistochemically, using two anti-p53 antibodies, CM1 and DO1. The same results were obtained with both antibodies. The epidermis central to the cornoid lamellae was positive in 8 of 9 specimens. On the other hand, the peripheral epidermis was positive in 2 of the 9 cases. The epidermis beneath the cornoid lamellae was positive in 3 of the 9 cases. The frequency of p53 positivity was significantly higher in the epidermis central to cornoid lamellae over that beneath or peripheral to them (Fisher's exact probability test, p<0.05). The majority of squamous cell carcinoma cells arising on giant porokeratosis stained with CM1 and DO1. These data may suggest that the abnormal p53 expression has some relevance to the skin carcinogenesis of porokeratosis.     

Mibelli's porokeratosis gigantea

This case report deals with the giant form of porokeratosis of Mibelli, porokeratosis Mibelli gigantea. Over the last 40 years, the 55-year-old man concerned had observed a centrifugal expansion of a single hyperkeratotic lesion until it covered the whole of the right hand and forearm. Besides the characteristic histological alterations, we saw capillaries with unusually thickened walls owing to basal lamina multiplication. In the centre of the lesion atrophy of the epidermis and of the corium was visible. These observations indicate an alteration in two germ layers in porokeratosis.     

A Case of Disseminated Superficial Porokeratosis Associated with Giant Porokeratosis in Pregnancy

A 23-year-old pregnant lady presented with dark raised lesions over face, axillae, and upper limbs of 15-day duration. She was 35 weeks pregnant at the time of onset of the lesions. Dermatological examination revealed hyperpigmented plaques on the face and papules with raised borders in the axillae and proximal arms. Skin biopsy from both the lesions revealed a diagnosis of porokeratosis. She was treated with emollients alone and the lesions regressed four weeks following delivery. This case is being reported for the rare occurrence of the combination of disseminated superficial porokeratosis with giant porokeratosis in pregnancy.     

Linear porokeratosis with multiple squamous cell carcinomas successfully treated by electrochemotherapy

Porokeratosis is a clonal epidermal disorder of keratinization characterized by annular lesions with an atrophic centre and a hyperkeratotic edge. The cornoid lamella is the histopathological hallmark. Six clinical variants are recognized: porokeratosis of Mibelli; disseminated superficial porokeratosis; disseminated superficial actinic porokeratosis (DSAP); porokeratosis plantaris et palmaris disseminata; punctate porokeratosis and linear porokeratosis. Linear porokeratosis is the type most frequently associated with malignant transformation into squamous cell carcinoma (SCC). It is thought to represent a mosaic form of DSAP and has an incidence of less than 1 in 200 000; treatment options are limited. We describe a patient with systematized linear porokeratosis and multiple SCCs who was successfully treated with bleomycin electrochemotherapy (ECT), a form of intralesional chemotherapy. In view of their large number, the individual SCCs were treated with bleomycin ECT. One year post‐treatment the patient remains tumour free. To our knowledge, this is the first case of multiple SCCs treated by ECT in the context of systematized linear porokeratosis. Our case highlights the challenges associated with diagnosing and managing this unusual form of porokeratosis.     

Fatal squamous cell carcinoma arising from transplant-associated porokeratosis

Porokeratosis is a disorder of epidermal keratinization characterized by variably sized plaques with central depression and a well-demarcated keratotic border. Associations of porokeratosis with immunosuppression and of porokeratosis with malignancy have been observed. The authors report a case of fatal metastatic squamous cell carcinoma arising from porokeratosis in an immunosuppressed patient.     

Porokeratosis of Mibelli following bone marrow transplantation

BACKGROUND: Porokeratosis is a rare disorder of keratinization with both autosomal dominant and acquired forms. Immunosuppression has been associated with the development of porokeratosis in numerous case reports and series. To our knowledge, however, only five cases of porokeratosis have been reported following bone marrow transplantation. RESULTS: We report five cases of porokeratosis of Mibelli following bone marrow transplantation. The diagnosis of porokeratosis was made between 1 and 13 years post-transplantation. The underlying malignancy in four of the five cases was leukemia, while the fifth patient had non-Hodgkin's lymphoma. Porokeratosis developed during remission in the four leukemia patients, whereas, in the fifth patient, it occurred during a relapse of lymphoma. CONCLUSIONS: Porokeratosis may develop following bone marrow transplantation. Our five cases double the number reported in the medical literature, and the incidence of porokeratosis following bone marrow transplantation may be significantly higher than previously recognized. As cutaneous carcinomas have been reported in association with porokeratosis, careful surveillance for porokeratosis in bone marrow transplant recipients is warranted.     

Generalized linear porokeratosis: a rare entity with excellent response to acitretin

Linear porokeratosis is a rare disorder of keratinization that usually presents at birth. We report a 17-year-old male with generalized linear porokeratosis, a very rare variant of porokeratosis, with extensive involvement of the trunk and extremities along with nail and genital involvement. The patient was treated with oral acitretin with excellent clinical response.     

Eruptive inflammatorische disseminierte Porokeratose bei einer 71-jährigen Patientin

The inflammatory stage of disseminated superficial porokeratosis is a rare disease, which has only been described in case reports, primarily affecting Japanese patients. After having asymptomatic disseminated superficial porokeratosis for years, a typical patient then experiences a sudden exacerbation with distinct pruritus. Histologically, the lesions may show eosinophilic spongiosis in addition to the characteristic cornoid lamella. We describe a 71-year old patient with clinically and histologically diagnosed inflammatory stage of disseminated superficial porokeratosis.     

Co-existence of variants of porokeratosis: a case report and a review of the literature

Rarely, different variants of porokeratosis may coexist in an individual patient or their family members. A patient with the linear form of porokeratosis present since birth subsequently developed the disseminated superficial actinic form at a later age. A review of the literature pertaining to the coexistence of variants of porokeratosis suggests a significant association between the linear and disseminated superficial actinic forms. Genetic linkage between different variants and the basis for their association is discussed.     

Clinical course of porokeratosis ptychotropica over 7 years in an otherwise healthy child

Porokeratosis ptychotropica is an unusual variant of porokeratosis characterized by papules and plaques located on the buttocks and gluteal cleft and showing multiple coronoid lamellae on histology. In this case report, we present the longitudinal clinical course of porokeratosis ptychotropica in a pediatric patient with individual red-brown hyperkeratotic lesions that enlarged and became confluent prior to surgical intervention. We also discuss the etiology of porokeratosis ptychotropica and review current as well as future treatment options for the disease.     

Porokeratosis in Singapore: an Asian perspective

Porokeratosis is a rare disorder of skin keratinisation characterised by a cornoid lamella. We reviewed its associations with immunosuppression and phototherapy, as well as the risks of malignant progression. This is a retrospective review on all cases of porokeratosis seen at the National Skin Centre, Singapore, between 2000 and 2010. A total of 94 patients were reviewed. Clinical and histological diagnoses were confirmed in 63% patients. Most patients were Chinese (89%) with a mean age of 51.6 years. The male to female ratio was 1.4:1. The four main clinical variants were classical porokeratosis of Mibelli (56%), disseminated superficial actinic porokeratosis (DSAP) (18%), disseminated superficial porokeratosis (DSP) (11%), and linear porokeratosis (13%). Phototherapy-induced porokeratosis, seen in three patients, is rare. Seven cases of porokeratosis occurred in patients who were immunosuppressed. Progression of porokeratosis to malignancy is uncommon and was observed in three patients. The most common treatments included cryotherapy (26.5%) as well as topical steroids or retinoids (38.1%). A good response, defined as clear or almost clear lesions, occurred in 16% patients. The most common presentation of porokeratosis in our review was a middle-aged male patient with an asymptomatic lesion of porokeratosis of Mibelli over the extremities. No particular immunosuppressive drug was implicated. Porokeratosis associated with ultraviolet phototherapy or malignancy is rare. Progression of porokeratosis to malignancy arose in the disseminated variants, with a possible correlation with age. This is the largest institutional retrospective review of porokeratosis to date and highlights the major epidemiological characteristics of this condition.     

Topical photodynamic therapy in disseminated superficial actinic porokeratosis

Photodynamic therapy (PDT) has been reported to be useful in treating certain nonmelanoma skin cancers and a variety of benign skin conditions. We examined whether PDT might be effective in the treatment of disseminated superficial actinic porokeratosis. Three patients with classical disseminated superficial actinic porokeratosis had a small test area treated with topical aminolaevulinic acid PDT. Following the first treatment, the disorder cleared in the test area in one patient, but failed to respond in the other two patients. After subsequent treatment, the initial benefit seen in the first patient was not sustained, and no response was seen in the second patient, while the third patient was not retreated due to hyperpigmentation induced by the procedure. The results obtained in this small case series suggest that topical PDT is not a promising treatment for disseminated superficial actinic porokeratosis.     

Simultaneous development and parallel course of disseminated superficial porokeratosis and ovarian cancer: Coincidental association or true paraneoplastic syndrome?

Disseminated superficial porokeratosis has been described in the setting of immunosuppressive conditions, including organ transplantation, infections, and hematopoietic malignancies. The outbreak of disseminated superficial porokeratosis during the development of solid organ malignancies has been rarely reported in the literature in patients affected by hepatitis C virus-related hepatocellular carcinoma or by cholangiocarcinoma, which suggests a paraneoplastic nature of the cutaneous disease. We report an unusual case of disseminated superficial porokeratosis in a patient affected by ovarian cancer, characterized by simultaneous onset and a parallel course of the two pathologies; there was good clinical response to chemotherapy, accompanied by a successful stop of disseminated superficial porokeratosis progression and gradual clearing of the keratotic lesions.     

Linear porokeratosis with giant cornoid lamella.

A linear form of porokeratosis, with features that we believe have not been previously described, is presented. The lesions occurred in a dermatome distribution; some of them had a central mass of parakeratotic keratin, shaped like a horn, which we designated a "giant cornoid lamella."     

Malignant disseminated porokeratosis

A patient has been observed with a distinct form of disseminated porokeratosis. During the course of his disease, he developed changes in the porokeratosis lesions that included cellular atypia, dysplasia, and invasive squamous cell carcinoma. One of the squamous cell carcinomas produced regional and disseminated metastases, resulting in the death of the patient. Although malignancy has been previously described in the various types of porokeratosis, this is the first report of disseminated metastases and death in any form of this disease.