Cutaneous Horn Presentation in Porokeratotic Eccrine Ostial and Dermal Duct Nevus. A Brief Review and Case Report

ABSTRACT

Porokeratotic eccrine ostial and dermal duct nevus is a rare adnexal hamartoma characterized by the presence of a cornoid lamella exclusively overlying eccrine acrosyringia. Different clinical presentations have been reported in the literature. Here, we report a case of a 6-year-old girl diagnosed with porokeratotic eccrine ostial and dermal duct nevus confirmed by histopathologic study. Atypical lesions are described as whitish, warty-looking neoformations located in the anterolateral region of the right hip (cutaneous horn).

Porokeratotic Variant of Lichen Planus

A 44-year-old woman presented with mildly itchy, brownish-black plaques for the last 2 years. The lesions first appeared on the upper back, followed by involvement of the face and upper arms within 4-5 months. Individual lesions began as small papules that gradually evolved into small, annular, and barely palpable plaques. There were no systemic complaints, photosensitivity, or history of intake of prolonged medication. Cutaneous examination revealed multiple, well-demarcated, and hyperpigmented oval to round plaques on the photo-exposed area, including the face, bilaterally on arms, and upper trunk, measuring about 1 × 1-3 × 3 cm² in size (Figures 1A and 1B). Dermatoscopic examination established rolled-out, thread, double-marginated border with central atrophy with a brownish reticular background. Multiple brownish to black globules and dark lacunae were also observed (Figures 1C and 1D). No Wickham's striae were viewed. Combination of clinical presentation with dermatoscopic findings indicated a provisional clinical diagnosis of disseminated superficial porokeratosis. Biopsy performed on the upper back revealed hyperkeratotic epidermis with mild lymphocytic exocytosis and spongiosis with pigmentary incontinence. The coronoid lamina was not revealed in any of the pathologic sections examined, including further deeper sections and in a repeat biopsy. Clinical morphology, dermatoscopic features, and pathology were considered compatible with the diagnosis of porokeratotic variant of lichen planus (LP). The patient was counseled and started on topical steroids (fluticasone). She is on regular follow-up.

Porokeratosis ptychotropica: a rare variant that is commonly misdiagnosed

Porokeratosis ptychotropica (PP) is a rare variant of porokeratosis characterized by pruritic, scaly papules and plaques localized to the perianal and gluteal cleft regions. Clinically, PP resembles other common disorders, resulting in frequent misdiagnosis. The diagnosis of PP often takes several years to make, therefore many reported cases in the literature described the late stages of PP. We report a case of PP diagnosed at an early stage. By presenting our patient, we aim to raise further awareness of PP to avoid a delay in diagnosis, thus preventing long term complications of this rare entity.

Eruptive pruritic papular porokeratosis or inflammatory form of disseminated superficial porokeratosis: a new case and review of the literature

Porokeratosis is a heterogeneous group of dermatoses with alterations of keratinization. Histologically, they are characterized by the presence of cornoid lamellae. Eruptive pruritic papular porokeratosis (EPPP) or the inflammatory form of disseminated superficial porokeratosis (or eruptive disseminated porokeratosis) is an infrequent variant, characterized by pruritic erythematous papules or annular lesions. We present a 72-year-old woman with EPPP, exhibited by pruritic lesions on the extremities and back, and review the literature concerning this condition. We found 32 cases of EPPP or inflammatory disseminated superficial porokeratosis (including the current case) reported in the literature, with a median age of 66 years (range, 13-84); 59.3% were men. Eruptive pruritic papular porokeratosis was associated with various neoplasms in 31.2% of cases. Six patients had an associated viral infection. Response to treatment was poor in most cases. Eruptive pruritic papular porokeratosis resolved spontaneously in 75% of cases. Median time to resolution was 6 months (range, 1-24). Eruptive pruritic papular porokeratosis (or inflammatory disseminated superficial porokeratosis/eruptive disseminated porokeratosis) is an infrequent variant of porokeratosis characterized by intense pruritus and spontaneous resolution in most individuals. Eruptive pruritic papular porokeratosis can be associated with neoplasms and screening for malignancies is recommended if clinically indicated.

Lichenoid inflammation of DSAP lesions following treatment with durvalumab, olaparib and paclitaxel: A potential diagnostic pitfall mimicking lichenoid drug eruptions associated with PDL-1 inhibitors

Disseminated superficial actinic porokeratosis (DSAP) is an uncommon skin condition that can be inherited or may occur sporadically with multiple red-brown, thin plaques in a photodistribution. The condition more often affects middle-aged women and is often recalcitrant to therapy. In rare literature reports, systemic medications can trigger exacerbation or promote inflammation in pre-existing lesions of DSAP. We present a novel case of chemotherapy-associated DSAP inflammation in a 66-year-old woman after triple therapy with durvalumab (PD-L1 inhibitor), olaparib (PARP inhibitor) and paclitaxel, showing similarities to primary lichen planus-like eruption from immune checkpoint inhibitors.

Adult-onset porokeratotic eccrine ostial and dermal duct nevus:dermatoscopic findings and treatment with tazarotene

Porokeratotic eccrine ostial and dermal duct nevus (PEODDN) is a rare dermatosis initially described as 'comedo nevus' and renamed 'PEODDN'; it has also been referred to as linear eccrine nevus with comedones, porokeratotic eccrine ostial and hair follicle nevus, and porokeratotic adnexal ostial nevus. PEODDN is usually present at birth or develops early in life. Rarely, PEODDN can develop in adults. The treatment of this puzzling condition is not standardized. We report herein a new case of adultonset PEODDN with dermatoscopic images. Our patient responded favorably to topical tazarotene.

Squamous cell carcinoma arising from giant porokeratosis and rare postoperative recurrence and metastasis: A case report

RATIONALE

Giant porokeratosis is considered to be a variant of porokeratosis of Mibelli (PM) by some medical scholars. Porokeratosis can develop into several epidermal malignant tumors, such as Bowen disease and basal cell carcinoma, among which squamous cell carcinoma (SCC) is the most common.

PATIENT CONCERNS

The patient was a 53-year-old man who was admitted to our hospital due to postoperative recurrence and metastasis as SCC arising from giant PM in his left leg and foot.

DIAGNOSES

The pathological results are porokeratosis and well-differentiated squamous cell carcinoma. Positron emission tomography and computed tomography results show the local recurrence of the tumor with multiple lymph node metastasis.

INTERVENTIONS

This patient was transferred to orthopedic surgery for amputation of the middle and lower left thigh.

OUTCOMES

Follow-up for 3 months has shown no recurrence after the surgery.

LESSONS

This report reminds us to pay close attention to the likelihood of giant porokeratosis. The physicians should explore all clinical possibilities to avoid misdiagnosis of this rare disease.Although the recurrence rate of SCC arising from giant PM is very low, the surgical resection region should be expanded appropriately such as the en-block resection.

Pink verrucous plaque in a man with systemic mastocytosis

Porokeratosis ptychotropica is a rare and commonly misdiagnosed subtype of porokeratosis involving the body folds. We present a 53-year-old man with systemic mastocytosis who presented with a pruritic, verrucous plaque in the gluteal fold that showed multiple cornoid lamellae on histopathologic evaluation, diagnostic of porokeratosis ptychotropica. Various treatments have been reported, including topical corticosteroids, retinoids, vitamin D analogs, calcineurin inhibitors, imiquimod, phototherapy, cryotherapy, or ablative laser therapy, but recurrences are common.

An unusual spiculated presentation of follicular porokeratosis

Follicular porokeratosis is a rare variant of porokeratosis in which the coronoid lamellae are confined to hair follicles. It classically presents with annular plaques with a surrounding keratotic ridge. However, the clinical presentation has shown significant variation in reported cases. We present the case of a 26-year-old man with chronic diffuse follicular spicules associated with alopecia. Clinical findings were suggestive of trichodysplasia spinulosa, but multiple biopsies showed findings consistent with follicular porokeratosis. Diffusely spiculated presentation as present in our patient has not been previously reported in the literature. It is important to recognize the necessity of histopathologic confirmation in a diagnostically challenging condition such as follicular porokeratosis.

Temozolomide-induced inflammation of disseminated superficial actinic porokeratosis

We report a case of temozolomide (TMZ)-induced inflammation of disseminated superficial actinic porokeratosis (DSAP), an uncommon and pre-malignant cutaneous disorder. Dermatologists and oncologists should be aware of this cutaneous eruption of DSAP associated with TMZ to prevent the discontinuation of effective medical therapy in cancer patients.

Linear porokeratosis associated with multiple squamous cell carcinomas

Linear porokeratosis is a rare subtype of porokeratosis with a higher rate of malignant transformation than other subtypes of porokeratosis. Identification of cornoid lamellae on histology allows for definitive diagnosis, which makes high clinical suspicion and appropriate biopsy essential in establishing the correct diagnosis and developing an effective management plan. We present a case report of linear porokeratosis and discuss aspects of etiology, diagnosis, and management.

Disseminated superficial actinic porokeratosis treated with ingenol mebutate gel 0.05

Disseminated superficial actinic porokeratosis (DSAP) is a chronic condition characterized by numerous atrophic papules and patches with a distinctive peripheral keratotic ridge, typically found on sun-exposed areas. Treatment of DSAP is warranted not only for cosmetic and symptomatic benefits but also to prevent malignant transformation. Successful treatment of DSAP often is difficult and frequently requires the use of multiple modalities. Ingenol mebutate gel 0.05% is a topical medication primarily used for the treatment of actinic keratosis (AK) by inducing cell death. We report a case of DSAP treated effectively with ingenol mebutate gel 0.05%.

Porokeratotic Adnexal Ostial Nevus-Report of a Case With Unusual Clinical and Histologic Features

An 11-year-old Tanzanian girl presented with diffuse verrucous lesions of varying morphology, scarring alopecia, and keloid scars over the face with a predilection for the ears. Physical examination revealed dark keratoderma and patches of hypopigmentation near the midline of the dorsal trunk (Figure 1a). Her forearms were densely covered by verrucous lesions with the exception of a clear linear patch on the dorsal aspect of the left forearm (Figure 1b). The perioral area was notable for white spires projecting from verrucous papules (Figure 1c) while the oral mucosa and teeth appeared normal on visual examination. The rest of her body, including the palms and soles, was covered by patchy, scaly lesions of varying severity.

Diagnosing porokeratosis of Mibelli every time: a novel biopsy technique to maximize histopathologic confirmation

Porokeratosis of Mibelli (PM) is a rare condition with the potential for malignant transformation that presents a clinical and pathologic diagnostic challenge. An improperly oriented biopsy may lead to the wrong histopathologic diagnosis. We report a case of PM that was previously misdiagnosed and describe a biopsy technique for suspected PM that maximizes the potential for histopathologic confirmation of the diagnosis.

Porokeratosis with follicular involvement: report of three cases and review of literatures

Porokeratosis is characterized clinically by annular plaques with a distinct peripheral keratotic ridge and histologically by the cornoid lamella. Porokeratosis with follicular involvement is rarely reported. To provide the basis of that follicular porokeratosis is a clinical variant or not. Biopsy was taken from three patients who were diagnosed porokeratosis. Routine stain was made and reviewed the literatures about well-documented cases of porokeratosis with follicular involvement. Porokeratosis with follicular involvement may have some clinical features: asymptomatic, erythematous, brownish or skin-color, less than 1 cm in the areas excluding palm and plantar, which commonly involved on middle-age. But there have still not enough proof as an independent clinical variant.

Porokeratotic eccrine ostial and dermal duct nevus - revisited

We hereby report a rare case of a 14-year-old girl presenting with asymptomatic pitted papules over the flexor aspect of her right 4th and 5th digits. This was histopathologically proven to be porokeratotic eccrine ostial and dermal duct nevus (PEODDN).

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.

A Case of Extensive Linear Porokeratosis with Evaluation of Topical Tretinoinversus5-Flourouracil as Treatment Modalities

A 19-year-old male presented with linear raised lesions over extensive areas of his body that followed Blaschko's lines. The lesions were asymptomatic with ridged borders. Histopathology confirmed a diagnosis of porokeratosis. He was given topical tretinoin and topical flourouracil for local application on specified areas. The cosmetic acceptability and the safety profile of tretinoin were found to be better than those of flourouracil. However, both the agents were equally efficacious. A rare case of extensive porokeratosis with comparative evaluation of two treatment modalities is hereby presented.

Inflammatory Stage of Disseminated Superficial Porokeratosis

Disseminated superficial porokeratosis (DSP) is a keratinization disorder characterized by multiple small lesions with a slightly elevated, sharply defined ridge over the whole body. Unusual DSP cases with acute exacerbation of their lesions accompanied by severe pruritus have been reported and designated as "eruptive pruritic papular porokeratosis" or "inflammatory DSP". Histologically, the pruritic lesions in the majority of these unusual DSP cases had a dense infiltration of eosinophils and lymphocytes in the vicinity of blood vessels in the upper dermis. In this report, we describe an additional case of DSP with a similar clinical course and histopathological findings. A review of the literature showed that the pruritic condition in these unusual DSP cases can be transient and is not necessarily related to spontaneous regression. We propose the term "Inflammatory stage of DSP" for describing this unusual variant of DSP.

Porokeratosis ptychotropica: a rare variant of porokeratosis

BACKGROUND

Porokeratosis, a well recognized disorder of keratinization, is known to have several clinical variants. This report describes a rare variant characterized by verrucous plaques.

METHODS

An adult male presented with a slowly progressive verrucous plaque on the gluteal region that was resistant to conventional therapy. Careful inspection revealed a keratotic ridge at the plaque border leading to the diagnosis.

RESULTS

Histopathology showed the presence of multiple cornoid lamellae confirming the diagnosis of porokeratosis ptychotropica.

CONCLUSIONS

Porokeratosis ptychotropica is a rare variant of porokeratosis with fewer than 25 cases described in the literature. This report is to highlight the importance of considering this particular entity in the diagnosis of genitogluteal plaques, especially those not responding to conventional modalities.

Adult onset unilateral systematized porokeratotic eccrine ostial and dermal duct nevus: a case report

Porokeratotic eccrine ostial and dermal duct nevus (PEODDN) is an uncommon, benign dermatosis that is characterized by asymptomatic grouped keratotic papules and plaques with a linear pattern on the extremities with distinct porokeratotic histopathological features. The lesions usually appear at birth or in childhood, although rare cases of late-onset adult PEODDN have been described. Herein we report a case of adult onset PEODDN with unilateral and segmental involvement.

Co-existence of porokeratosis variants concurrent with Bowen's disease: two rare cases report

Coexisting variants of porokeratosis rarely occurs. Disseminated superficial porokeratosis (DSP) is characterized by multiple uniform small annular papules distributed all over body. DSP commonly coexist with linear porokeratosis (LP), but it is uncommon for DSP to coexist with porokeratosis of Mibelli (PM). PM presents with central atrophic erythematous plaques and thread-like elevated border. It occurs mainly on extremities. Although malignant transformation can be found in the porokeratosis, there is still no report case of coexisting variants of porokeratosis concurrent with Bowen's disease. The clinical and histopathologic finding of rare coexisting variants of porokeratosis (PM and DSP) concurrent with squamous dysplasia is described.

Detection of a novel missense mutation in the mevalonate kinase gene in one Chinese family with DSAP

Disseminated superficial actinic porokeratosis (DSAP) is the most common form of porokeratosis and a severe chronic autosomal dominant cutaneous disorder with high genetic heterogeneity. Recently, the mevalonate kinase (MVK) gene has been identified as a candidate gene responsible for DSAP and multiple mutations have been reported. Here, we report identification of a novel missense mutation in the MVK gene in a Chinese family with DSAP. A 50-year-old male was diagnosed as proband of DSAP based on the clinical and histological findings, which show numerous hyperpigmented macules by physical examination and cornoid lamella by skin biopsy. Similar skin symptoms were also observed in his father, who died many years ago. We prepared genomic DNA from the proband, unaffected individuals from his family members, as well as 100 unrelated healthy controls. PCR was then conducted using the above genomic DNA as template and the MVK gene-specific primers. The PCR product was subjected to direct sequencing and the sequence was compared to that of MVK gene within the NCBI database. We detected a heterozygous C to G transition at nucleotide 643 in exon 7 of MVK gene of the proband. This will result in an amino acid change at codon 215 (P.Arg215Gly.), which is from an arginine codon (CGA) to a Glycine codon (GGA). We did not detect any mutation in the unaffected family members or the 100 unrelated healthy controls, demonstrating that this is a novel missense mutation in MVK gene and therefore, contributes to the molecular diagnosis of DSAP.

Disseminated superficial actinic porokeratosis

Disseminated superficial actinic porokeratosis, which was described in 1966, is characterized by small, atrophic patches with distinctive keratin rims that occur on sun-exposed areas of the extremities, shoulders, and back. The diagnosis is based on the histopathologic finding of a cornoid lamella, absence of a granular layer, and often a thin epidermis. It is associated with exposure to ultraviolet radiation. Gene studies suggest a pathway defect in which several mutations in keratinocyte proliferation and differentiation lead to development of porokeratosis.

Localized actinic nasal porokeratosis: a case report

Porokeratisis is a specific keratinization disorder. The presence of cornoid lamella is histologically characteristic of the disorder. This report describes a 23-year-old male patient with multiple porokeratotic lesions with bilateral symmetric localization on the ala of the nose, which may be a rare variant of porokeratosis.

Isolated single digit Porokeratosis of Mibelli: an unusual case

Porokeratosis of Mibelli is an uncommon dermatosis, which may be associated with immunosuppression and which may undergo malignant transformation. We report a patient with a chronic history of a skin lesion of his right 5th finger that was histologically confirmed to be Porokeratosis of Mibelli. Although it commonly affects the extremities, the isolated involvement of an individual digit of the hand has not been previously reported.

A case of porokeratosis plantaris palmaris et disseminata and literature review

Porokeratosis plantaris palmaris et disseminata (PPPD) is a quite rare variant of porokeratosis. We report a 56-year-old male patient. He first noted brownish, asymptomatic, annular macules scattered on the trunk and extremities at about age 31 and these skin lesions, continued to increase in number. Ten years prior to presentation, similar lesions appeared on the palms. About one to two years ago, the patient noted painful wart-like, keratotic punctuate papules 2-3 mm in diameter on the soles, which disturbed walking. Histological examination showed the characteristic feature of the cornoid lamella. The family tree of this patient showed an autosomal dominant mode of transmission. We review sixteen typical cases of PPPD previously reported in the English literature.

Multiple keratotic papules on palm

Porokeratotic eccrine ostial and dermal duct nevus (PEODDN) is a rare nonhereditary malformation of the eccrine duct. A relationship with linear porokeratosis is not yet established; some consider it as a rare variant of porokeratosis involving the acrosyringium, whereas others consider it a separate entity based on distinctive clinical features and histologic accentuation within ostial structures. A 7-year-old girl presented with multiple asymptomatic keratotic papules over her right palm, present since the age of 6 months. These papules were arranged in a linear distribution over the palm and middle finger of the right hand. Most of the papules were discrete. However, lesions on the middle finger coalesced to form a plaque. Histology revealed a keratin filled deep invagination of the epidermis, notable for a column of parakeratosis ("cornoid lamella"). The dermis was notable for dilated eccrine ducts and absent inflammation. Considering the clinical and histological evidence, a diagnosis of PEODDN was made. Its clinical resemblance to linear lichen planus and linear porokeratosis is discussed. Also, we provide a brief review of this rare condition.

Porokeratotic eccrine ostial and dermal duct nevus treated with a combination erbium/CO2 laser: a case and brief review

Porokeratotic eccrine ostial and dermal duct nevus (PEODDN) is an uncommon disease that presents early in childhood and is characterized by keratotic papules, often in a linear configuration. We describe a 12-year-old girl with characteristic lesions of PEODDN and describe her response to treatment with a combination CO2/Erbium laser. We also briefly review the literature on PEODDN.

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.

Development of disseminated superficial porokeratosis in a patient with complicated acute pancreatitis

Porokeratosis is a group of hereditary or acquired diseases with abnormal epidermal keratinization. A 71-year-old man was admitted to the Surgery Department after an attack of acute pancreatitis complicated with pancreatic necrosis, which required surgical resection. Three weeks after the admission, the patient was observed by our Dermatology department with sudden onset of a generalized eruption of asymptomatic flat papules with a hyperkeratotic rim, sparing the face, palms, soles, and mucous membranes. A skin biopsy was performed at the border of a leg lesion, which disclosed the presence of cornoid lamella, confirming the clinical diagnosis of disseminated superficial porokeratosis (DSP). The skin eruption spontaneously subsided about one month after pancreatic resection. The late onset of DSP in our patient may represent a type of immunosuppression-induced porokeratosis. Possibly, the pathologic clone of keratinocytes for porokeratosis was present, but remained latent until there was a decrease in the immunological status. It is possible that this relative and transient state of immunosuppression was the result of the concurrent necrotizing pancreatitis. This case represents an unusually good outcome of DSP. To the authors best knowledge, this is the first case of DSP related to severe acute pancreatitis.

Facial and bilateral acral porokeratosis with nail dystrophy: A case report

Porokeratosis is a rare disorder of keratinization with unknown etiology. It exhibits both sporadic and autosomal dominant inheritance. The lesions are sharply demarcated, hyperkeratotic, and annular with distinct keratotic edges. The cornoid lamella is the histological hallmark of porokeratosis. Porokeratosis lesions on the face may have a superficial or a destructive nature. To our knowledge there are only a few cases of facial porokeratosis that have been reported. We report a sporadic form of facial and bilateral acral porokeratosis with nail dystrophy.

Disseminated porokeratosis of Mibelli: A case report

Porokeratosis is a disorder of clonal hyperproliferation of keratinocytes with several different clinical manifestations. Cutaneous lesions vary in their appearance and distribution. All variants share the distinguishing cornoid lamella on histopathological examination. We present an unusual case of disseminated porokeratosis of Mibelli in an immunocompetent patient.

Disseminated superficial porokeratosis

A 62-year-old woman with psoriasis and psoriatic arthritis presented for evaluation and treatment of a one-week history of pruritic, pink spots on her trunk and extremities. Several weeks prior, therapy with certolizumab pegol and methotrexate was started for her psoriatic arthritis. A biopsy specimen was consistent with the diagnosis of porokeratosis. Owing to the setting of immunosuppression and presence of symmetric pruritic lesions on non-sun exposed areas, the diagnosis of disseminated superficial porokeratosis was made.

Porokeratosis plantaris, palmaris, et disseminata

We describe a 73-year-old woman with a long-standing history of annular, hyperkeratotic papules that began on the palms and soles and gradually spread to her trunk, extremities, and face. The clinical presentation and biopsy findings were consistent with PPPD, which is a rare subtype of porokeratosis that begins on the palms and soles and gradually spreads to the trunk and extremities. Owing to the risk of malignant degeneration in porokeratosis, patients should be closely monitored with total body skin examinations. There is no definitive treatment for PPPD. Oral retinoids are sometimes helpful although relapses are common after discontinuation of therapy.

Disseminated superficial porokeratosis and pyoderma gangrenosum

Disseminated Superficial Actinic Porokeratosis (DSAP) is usually triggered by sun exposure. In some cases sun exposure is not essential and this skin disease is related to immunosuppression. Many associated diseases are described in the literature. We report a clinical case of a patient affected by pyoderma gangrenosum, who developed DSAP.