Porokeratosis: A Review of Its Pathophysiology, Clinical Manifestations, Diagnosis, and Treatment

A Case of Squamous Cell Carcinoma Arising in Disseminated Superficial Porokeratosis

Porokeratosis (PK), characterized by keratotic lesions with an atrophic center and a prominent peripheral ridge, with a typical histological hallmark, namely, the cornoid lamella, has two forms: disseminated and localized. While PK often converts into squamous cell carcinoma (SCC), conversion from disseminated superficial porokeratosis (DSP) alone is rarely reported except for one case in which DSP and LP coexisted and converted to SCC. Here, we report the case of a patient with SCC converted from DSP alone, presenting with coin-sized macules on the bottom right of his waist that developed into an ulcer at the center. The patient underwent radiation therapy, which effectively treated the SCC but did not resolve the PK. This article highlights regular follow-up and undergo comprehensive diagnosis, both of which are beneficial to enable early detection and management of DSP that has converted to into SCC; in addition, standardized medical treatment may help improve the treatment therapeutic effect of in similar diseases.

Annular Pigmented Macules on the Upper Trunk: A Quiz

Abstract is missing (Quiz)

Porokeratosis of the scrotum: a case report and literature review

Porokeratosis, a keratinizing disorder of unknown etiology, exhibits an autosomal dominant inheritance pattern or manifests as an isolated acquired dermatosis. This condition can occur at any site on the skin; however, scrotal lesions are extremely rare. Only 18 cases of scrotal lesions were identified through a comprehensive review of the relevant literature. Herein, we present a case of a 19-year-old patient with porokeratosis of the scrotum. Additionally, we provide a summary of the etiologies, clinical manifestations, and histopathology of scrotal porokeratosis, and present differential diagnoses by reviewing the related literature.

Approach to the so-called "Invisible Dermatosis": When Subtle Histopathological Findings Guide Diagnosis

ABSTRACT

Invisible dermatosis is a concept that can be applied either to clinical or histopathological findings. We will focus on the dermatopathological aspect of this invisible dermatosis that can be seen as dermatosis with subtle histopathological findings that are mandatory to known to stablish the diagnosis. With a proper approach facing in depth the different skin layers from stratum corneum to subcutaneous tissue combined with some especial stains, special investigations and mostly a proper clinicopathological correlation, the problem of missing out a diagnosis can be decreased. We will review the general aspects for diagnosis and the peculiar findings of an in-depth review of them because it is important to note that minor changes on a skin biopsy do not mean it is disease free. We will review classic clues, we will add some new useful ones, and we will also provide a guide on the special stains helpful, such as periodic acid-Schiff when facing fungi, orcein-Giemsa and van Gieson when altered elastic fibers are suspected, or Pearl and Masson Fontana when an altered skin pigmentation is suspected.

Autophagy-related LncRNA PRDM10-DT responds to UVB radiation in keratinocytes

Ultraviolet (UV)-B radiation is a major environmental risk factor that is responsible for the development and progression of many skin disorders. Autophagy is the process of degradation and recycling of damaged cytoplasmic organelles, macromolecular aggregates, and long-lived proteins. Previously, we found that the autophagy inducer apigenin restored UVB-impaired autophagy and the cellular response by downregulating the expression of autophagy-related genes such as ATG5. To explore long noncoding RNAs (lncRNAs) involved in regulating these autophagy-related genes, in this study, we assessed the expression profiles of lncRNAs and mRNAs using a microarray in human epidermal keratinocytes (HEKs) treated with or without apigenin after UVB radiation. The expression levels of 80 selected autophagy-related genes and related lncRNAs were confirmed by quantitative real-time polymerase chain reaction (qRT‒PCR). The lncRNA PRDM10-DT was proposed to regulate IRGM based on the ceRNA and coexpression pattern and was demonstrated to be involved in autophagy regulation, proliferation and migration of HEKs by qRT‒PCR, Western blotting, colony formation and scratch wound assays, respectively. These findings suggest an autophagy-related lncRNA in response to UVB radiation that promotes the proliferation and migration of HEKs through inducing autophagy by competing microRNAs for IRGM.

Bilateral Linear Porokeratosis Treated With Topical Lovastatin 2% Monotherapy

Linear porokeratosis is a rare skin disorder that presents along dermatomal or Blashko lines. While the mechanism of linear porokeratosis formation is unknown, both disrupted cholesterol synthesis and mevalonate accumulation have been proposed as possible theories. There is a small chance of transforming into cutaneous malignancies, most commonly squamous cell carcinomas. The patient is a 61-year-old male with an unusual presentation of bilateral linear porokeratosis. His condition provided a unique opportunity to compare the efficacy of topical treatments in a single individual. A previous trial had successfully cleared the porokeratosis plaques with topical cholesterol 2%/lovastatin 2% on the patient's right arm. After a 12-week trial of topical lovastatin 2% monotherapy on the left arm, our current study demonstrated a comparable reduction of porokeratosis lesions. In our PubMed search, there has been a single reported case of disseminated superficial actinic porokeratosis successfully treated with topical lovastatin 2% monotherapy, but there have not been any reported cases of linear porokeratosis treated with this therapy. While topical lovastatin monotherapy for porokeratosis subvariants requires further studies, this case demonstrates similar efficacy of treating linear porokeratosis with topical lovastatin compared to cholesterol/lovastatin dual therapy. These findings support the theory of mevalonate accumulation as a more likely cause of linear porokeratosis compared to disruption of cholesterol synthesis.

Successful Treatment of Eruptive Pruritic Papular Porokeratosis in the Elderly with Tofacitinib: A Case Report

Eruptive pruritic papular porokeratosis (EPPP) is a rare subtype of porokeratosis that presents as an acute exacerbation of an annular papule with a distinct peripheral hyperkeratotic ridge border and severe pruritus. EPPP is mainly reported in elderly East Asian men. Its etiology and pathogenesis are unknown. We hereby present a case report of EPPP in a 68-year-old Chinese male with persistent circumscribed papules on the extremities, accompanied by severe pruritus for one year. After the patient was given conventional medication, a new rash appeared on the patient's extremities and he felt intense itching in the area of the rash. The patient was switched to oral tofacitinib treatment. The patient felt that the pruritus had largely disappeared after one month of oral dosing, leaving only brown pigmentation on the erythema of the extremities. The patient has been off the drug for 2 months. There was no pruritus or new rash during the follow-up period.

Combining Isotretinoin and Topical Cholesterol/Atorvastatin in the Treatment of Linear Porokeratosis: A Case Report

Linear porokeratosis (LP) is an epidermal keratinization disorder manifesting in the form of annular plaques with an atrophic center and hyperkeratotic margins. Although rare, LP carries a significant risk of skin cancer. Histological examination usually reveals the cornoid lamella, a parakeratosis column visualized in the outer layer of the epidermis. First-line treatment of LP is retinoids. However, the effects of combination therapy of isotretinoin and topical statins on LP are not well-understood. Herein, we attempted treatment with both isotretinoin and 2% cholesterol/atorvastatin ointment, with considerable improvement observed using the former but not the latter. These findings suggest that 2% topical cholesterol/atorvastatin treatment may not carry any additional benefits, even if used alongside retinoids. Further studies are needed to assess the potential effects of statins on LP.

Porokeratosis is one of the most common genodermatoses and is associated with an increased risk of keratinocyte cancer and melanoma

BACKGROUND

Porokeratosis is a clinically heterogeneous group of keratinization disorders with a genetic background mainly affecting the mevalonate pathway, which is involved in the synthesis of cholesterol, an essential component for the formation of the extracellular lipid lamellae in the stratum corneum. Porokeratosis is reportedly associated with an increased risk of keratinocyte cancer, but to date, no large epidemiological studies have been conducted to further address this association.

OBJECTIVES

The first objective was to characterize a cohort of patients diagnosed with porokeratosis at the Department of Dermatology and Venereology, Sahlgrenska University Hospital (SU), Gothenburg, Sweden. The second objective was to conduct a nationwide registry-based cohort study to investigate the association, if any, between porokeratosis and the cutaneous malignancies squamous cell carcinoma (SCC), basal cell carcinoma (BCC) and melanoma.

METHODS

For the SU cohort, the hospital registry was searched for patients with a diagnosis of porokeratosis recorded between 2016 and 2020. Clinical data were extracted from the records of the identified patients. For the nationwide cohort, national registries were searched to identify patients with a diagnosis of porokeratosis between 2001 and 2020. A tenfold control cohort was formed by Statistics Sweden. The data was cross-referenced with the Swedish Cancer Register to study the associations between porokeratosis and SCC, BCC and melanoma.

RESULTS

Disseminated superficial actinic porokeratosis was the most common clinical type among the 108 patients in the SU cohort. In the nationwide search, 2277 patients with porokeratosis were identified (prevalence 1/4132). Porokeratosis was associated with an increased risk for SCC, BCC and melanoma with hazard ratios (95% CI) of 4.3 (3.4-5.4), 2.42 (1.97-2.98) and 1.83 (1.18-2.82), respectively, in the patient cohort, compared to the matched control group.

CONCLUSION

Porokeratosis is a common genodermatosis, and it is associated with an enhanced risk of skin cancer.

Exclusive and Solitary Facial Porokeratosis: Pathogenesis and Literature Reappraisal of a Rare Entity

Porokeratosis is a group of well-known clinically distinct entities, characterised by different clinical aspects, but sharing a single common histological aspect, namely the cornoid lamella. Usually, porokeratosis occurs in the limbs and trunk, while it rarely involves the face, especially as an exclusive, single, and solitary lesion. We report the case of a 52-year-old Caucasian woman, with an 11-month history of a 2-cm slowly growing solitary, keratotic lesion on her left cheekbone. The patient did not present other cutaneous lesions on the face, as well as in other body sites. A cutaneous biopsy showed epidermal hyperplasia with multiple, sharply defined cornoid lamella, associated with an underlying attenuation of the granular layer and scattered dyskeratotic cells in the spinous layer. The superficial dermis underneath showed a mild lymphocytic infiltrate and fibrosis with remodelled collagen bundles. A final diagnosis of solitary facial porokeratosis was made.

Disseminated Superficial Actinic Porokeratosis (DSAP): A Case Report Highlighting the Clinical, Dermatoscopic, and Pathology Features of the Condition

Porokeratosis describes a heterogenic group of keratinization disorders in which lesions are papules and plaques that demonstrate central atrophy surrounded by a hyperkeratotic margin. Clinical variants include not only porokeratosis of Mibelli, but also disseminated superficial, disseminated actinic superficial, linear, punctate, and palmaris et plantaris disseminata. Porokeratosis has a risk of malignant transformation. A woman with disseminated superficial actinic porokeratosis (DSAP) whose lesions presented as pruritic plaques and papules is described. The diagnosis was suspected clinically, supported by dermoscopy findings, and confirmed histologically. The condition-associated pruritus was managed symptomatically; her skin lesions will be monitored clinically. Clinical manifestations, dermatoscopic features, pathology findings, and treatment options for DSAP are summarized.

Case of lichen planus with unusual features

A 25-year-old woman came with an itchy red rash on her back since 2 years ago. This lesion then extended to the abdomen, arms and legs. From the patient's back, we found irregular linear hyperpigmented patches with some of the edges in the form of hyperpigmented plaques. On the abdomen, arms and legs, erythema-hyperpigmented plaque and patches were visible along the elevated edges with multiple scattered sizes. Lichen planus (LP) has several types based on various clinical manifestations. The diagnosis of LP can be made based on the clinical appearance and symptoms of pruritus. Many diseases can mimic other diseases so histopathology is used to make the diagnosis. Here, we report a case of LP with unusual features with diagnosis confirmed by histopathological examination. The patient was treated with oral and topical potent corticosteroids with good response.

[Premalignant lesions of the penis]

The dermatological conditions that affect the penis are diverse, and may be typical of this area or be part of systemic diseases. The anamnesis and inspection are often sufficient for diagnosis, but other times, it is difficult to distinguish between benign dermatoses and premalignant lesions. The delay in consulting, due to fear, shame or the doctor's own ignorance, can cause the lesions to progress to malignancy and require aggressive treatments that can alter the quality of life and physical and mental health of the patient. We must suspect premalignancy or malignancy any lesion of the penis that is not modified with specific or empirical treatment and refer for biopsy. HPV infections are the origin of 50% of premalignant lesions. After treatment and due to possible relapses and progression to infiltrating carcinomas, a strict follow-up plan is necessary.

Dermoscopy of porokeratosis: results from a multicentre study of the International Dermoscopy Society

BACKGROUND

The diagnosis of porokeratosis can be challenging, and knowledge about its dermoscopic features is limited.

OBJECTIVES

To describe the dermoscopic features of porokeratosis of Mibelli and disseminated superficial actinic porokeratosis (DSAP) and the frequency of these features in a larger case series. The interobserver concordance was also assessed.

METHODS

In this retrospective cohort study, members of the International Dermoscopy Society contributed macroscopic and dermoscopic images of histopathologically verified cases of porokeratosis of Mibelli or DSAP. Three observers independently reviewed the collected images to identify the presence of predefined dermoscopic features. Following this, a consensus meeting was held to agree upon which dermoscopic features were present in each lesion.

RESULTS

In total, 78 clinical and dermoscopic images of porokeratoses were collected. The most common dermoscopic feature was keratin rim, which was present in 74 lesions (92.3%). The most common vascular structures were dotted or glomerular vessels which were present in almost half of the cases (48.7%). Other relatively frequent dermoscopic findings were as follows: non-peripheral scales (44.9%), grey-brown dots or pigmentation along the keratin rim (38.5%), and light-brown pigmentation within the keratin rim (33.3%). Shiny white structures and blood spots or erosions along the keratin rim were findings never before described in porokeratosis and were detected in 16.7% and 17.9% of the lesions, respectively. Dermoscopic findings in porokeratosis of Mibelli and DSAP were similar except for fewer blood spots or erosions along the keratin rim and more light-brown pigmentation within the keratin rim in DSAP. The interobserver concordance ranged from 0.44 (moderate) to 0.84 (almost perfect).

CONCLUSIONS

The dermoscopic hallmark of porokeratosis is the keratin rim, a finding also allowing for almost perfect interobserver agreement. Pigmentation or erosions along the keratin rim, vascular structures, as well as scales, pigmentation or shiny white structures within the keratin rim are additional dermoscopic clues.