Update of penetrance estimates in Birt-Hogg-Dubé syndrome.

BACKGROUND: Birt-Hogg-Dubé (BHD) syndrome is a rare genetic syndrome caused by pathogenic or likely pathogenic germline variants in the FLCN gene. Patients with BHD syndrome have an increased risk of fibrofolliculomas, pulmonary cysts, pneumothorax and renal cell carcinoma. There is debate regarding whether colonic polyps should be added to the criteria. Previous risk estimates have mostly been based on small clinical case series. METHODS: A comprehensive review was conducted to identify studies that had recruited families carrying pathogenic or likely pathogenic variants in FLCN. Pedigree data were requested from these studies and pooled. Segregation analysis was used to estimate the cumulative risk of each manifestation for carriers of FLCN pathogenic variants. RESULTS: Our final dataset contained 204 families that were informative for at least one manifestation of BHD (67 families informative for skin manifestations, 63 for lung, 88 for renal carcinoma and 29 for polyps). By age 70 years, male carriers of the FLCN variant have an estimated 19% (95% CI 12% to 31%) risk of renal tumours, 87% (95% CI 80% to 92%) of lung involvement and 87% (95% CI 78% to 93%) of skin lesions, while female carriers had an estimated 21% (95% CI 13% to 32%) risk of renal tumours, 82% (95% CI 73% to 88%) of lung involvement and 78% (95% CI 67% to 85%) of skin lesions. The cumulative risk of colonic polyps by age 70 years old was 21% (95% CI 8% to 45%) for male carriers and 32% (95% CI 16% to 53%) for female carriers. CONCLUSIONS: These updated penetrance estimates, based on a large number of families, are important for the genetic counselling and clinical management of BHD syndrome.

Myxoid Onychomatricoma-A New Case.

Onychomatricoma is a slow-growing, benign neoplasm of the nail matrix with several histological variants. With only 2 cases previously reported, the term "myxoid onychomatricoma" has been used by some authors to describe a rare variant, known to have a fibromixoid component. We present a case of a 51-year-old Caucasian woman with a 1-year history of thickening and discoloration of the right thumbnail, who was initially misdiagnosed as onychomycosis. After performing a magnetic resonance imaging that showed a tumor with several filamentous projections, an onychomatricoma was suspected and a total distal plaque avulsion was performed. Histology revealed a biphasic tumor with an epithelial component and a prominent myxoid stroma. Immunohistochemical staining was then used, confirming the diagnosis. Considering these findings, we believe that our case meets the diagnostic description of "myxoid onychomatricoma" and is, therefore, a new case of this rare histological variant.

Combined Use of Ex Vivo Dermoscopy and Histopathology for the Diagnosis of Melanocytic Tumors.

Dermoscopy can be applied to fixed tissues, and dermoscopic patterns correlate with microscopic findings. Data on the influence of ex vivo dermoscopy on pathologic diagnosis of melanocytic lesions are limited. Therefore, we aimed to determine whether this technique could aid on the histopathological evaluation of melanocytic neoplasms. Sequential cutaneous excisional biopsies of melanocytic lesions and their corresponding ex vivo dermoscopic images were prospectively analyzed. Additional sectioning was executed in areas of dermoscopic concern, having, by reference, a dermoscopic mapping of the sectioned specimens. Diagnostic differences before and after analyzing the new dermoscopy-guided sections were registered. A total of 564 melanocytic lesions were examined, and additional cuts were considered necessary in 84 (14.9%) cases. Of these, 11 lesions (13.1%) had a different final diagnosis after dermoscopy-guided specimen sectioning, including 3 lesions that were reclassified as melanomas and 2 melanomas that were restaged. We found that the combined use of ex vivo dermoscopy and histopathology improves clinical-pathological correlation and allows selection of representative areas for sectioning. Altogether, this technique may improve diagnostic confidence and accuracy in the histopathological evaluation of melanocytic lesions.

Surgery for benign nail tumor.

The vast majority of tumors in the nail apparatus have a different clinical presentation and course from their equivalents on the skin. Some, such as onychomatricoma and onychopapilloma, are unique to the nail and others, such as superficial acral fibromyxoma, have a tropism for the nail apparatus. As a rule, benign lesions respect the general architecture of the nail apparatus, whereas malignant tumors are destructive. Treatment is always surgical and good knowledge of the anatomy and the procedures is mandatory in order not to induce postoperative nail dystrophy.

Role of trichoscopy in children's scalp and hair disorders.

Hair and scalp disorders in children may originate from the hair itself, scalp skin, or infectious causes and be congenital or acquired. The most common sign is alopecia, frequently brought on by tinea capitis, patchy alopecia areata, or trichotillomania. Sometimes less frequent and clinically more elusive conditions such as initial androgenetic alopecia, congenital triangular alopecia, or alopecia areata incognita may be responsible for hair loss. The noninvasive technique known as trichoscopy is being used more frequently, aiding in the prompt differential diagnosis and follow-up of many of these diseases, oftentimes providing further examination before a treatment decision is made. This review of trichoscopy of the main scalp and hair disorders afflicting children and adolescents discusses the most important dermoscopic criteria and the usefulness of this technique.

Scleredema diabeticorum.

Scleredema of Buschke is a rare connective tissue disease with a poorly understood pathogenesis. Three types of scleredema have been distinguished according to its association with preceding or underlying conditions. Type 1 is usually secondary to a febrile infection, type 2 is mostly associated with paraproteinemia and type 3, usually named scleredema diabeticorum, has a strict association with Diabetes mellitus. A diffuse, non-pitting swelling and induration of the skin define this disease. The skin histology is characterized by a normal or slightly thinned epidermis, and the dermis containing a decreased number of elastic fibers and thick large swollen collagen bundles separated by mucopolysaccharide deposits in the deep reticular dermis. In this report we present a 58-year-old man with scleredema diabeticorum controlled with a topical steroid cream and an optimization of glycemic control. We reviewed clinical, histopathological characteristics and the various possible treatments.

Tocilizumab-Induced Erythema Annulare Centrifugum.

We report the case of a 42-year-old woman with rheumatoid arthritis undergoing treatment with subcutaneous tocilizumab for the past 6 months. Three days after the administration, an asymptomatic inflammatory annular plaque of 4 cm with discrete whitish scales at the inner border margin developed at the injection site in the left iliac fossa. A smaller plaque in the left groin appeared soon after. The mycological exam was negative. Histology showed a lymphoplasmacytic superficial and deep perivascular, and periadnexal, dermal infiltrate, without epidermal changes. Lesions spontaneously regressed in 4 months. The diagnosis was clinically and histologically consistent with erythema annulare centrifugum, following the exclusion of other differential diagnoses. Erythema annulare centrifugum represents a delayed-type hypersensitivity reaction generally considered idiopathic or otherwise related to numerous triggers, including drugs such as biologics. We describe the first reported case of tocilizumab-induced erythema annulare centrifugum. This case should alert dermatologists to this relatively rare and complex entity and should raise awareness to cutaneous biologic drug reactions.

Dermatitis Cruris Pustulosa et Atrophicans: Scarring Alopecia Beyond Scalp Hair.

Dermatitis Cruris Pustulosa et Atrophicans (DCPA) was first described in 1952 in Nigeria and is nowadays regarded as a type of chronic folliculitis of tropical areas. It is often limited to the lower limbs of young adults, mostly in the second to third decades, with a unique clinical picture characterized by chronicity, relentless progression, therapy refractoriness, and permanent cicatricial changes. Trauma, occlusion, and microorganism selection contribute for its etiopathogenesis, which is deemed multifactorial but still incompletely understood. Despite its conspicuous clinical features, awareness of DCPA is apparently low, hence probably overlooked. We herein summarize the current state of knowledge regarding this distinct entity, and further present the first report in a patient from Bangladesh, and concurrently the first in Europe. Paucity of data, and unraveled definite etiology and treatment, highlight the need for further studies.

Nail Disease: Clinical Decisions among Portuguese Dermatologists and Family Physicians.

Onychomycosis is one of the most common nail disorders and may be difficult to distinguish from other causes of nail dystrophy, based on clinical grounds alone. With this study, we aimed to describe the use of fungal testing by dermatologists and family physicians in their daily current practice, analyze their respective familiarity with nail disease diagnosis, and ultimately treatment decision-making by both groups. An online survey was distributed among Portuguese dermatologists, trainees, and family physicians by email. The survey focused on the diagnostic impression, use of diagnostic methods to confirm a fungal infection, and the subsequent assessment of treatment. One hundred fifty-one responses were obtained, 60 (39.7%) from dermatologists and 91 (60.3%) from family physicians; 98.3% of dermatologists mentioned usually requesting a fungal testing at their local institution or outside, while this percentage was 50.5% among family physicians (p < 0.001). Regarding the diagnosis, the median of correct diagnosis by the dermatologist group was higher (10/15) than the family physicians (6/15). Considering the treatment strategy, we observed that in the dermatologists' group it would result in unnecessary treatment in a median of 2 cases, while in the family physicians' group, in a median of 4 cases.