Position paper on a simplified histopathological classification of basal cell carcinoma: results of the European Consensus Project.

BACKGROUND: Histopathological classification of basal cell carcinoma (BCC) has important prognostic and therapeutic implications, but reproducibility of BCC subtyping among dermatopathologists is poor. OBJECTIVES: To obtain a consensus paper on BCC classification and subtype definitions. METHODS: A panel of 12 recognized dermatopathologists (G12) from nine European countries used a modified Delphi method and evaluated 100 BCC cases uploaded to a website. The strategy involved five steps: (I) agreement on definitions for WHO 2018 BCC subtypes; (II) classification of 100 BCCs using the agreed definitions; (III) discussion on the weak points of the WHO classification and proposal of a new classification with clinical insights; (IV) re-evaluation of the 100 BCCs using the new classification; and (V) external independent evaluation by 10 experienced dermatopathologists (G10). RESULTS: A simplified classification unifying infiltrating, sclerosing, and micronodular BCCs into a single "infiltrative BCC" subtype improved reproducibility and was practical from a clinical standpoint. Fleiss' κ values increased for all subtypes, and the level of agreement improved from fair to moderate for the nodular and the unified infiltrative BCC groups, respectively. The agreement for basosquamous cell carcinoma remained fair, but κ values increased from 0.276 to 0.342. The results were similar for the G10 group. Delphi consensus was not achieved for the concept of trichoblastic carcinoma. In histopathological reports of BCC displaying multiple subtypes, only the most aggressive subtype should be mentioned, except superficial BCC involving margins. CONCLUSIONS: The three BCC subtypes with infiltrative growth pattern, characteristically associated with higher risk of deep involvement (infiltrating, sclerosing, and micronodular), should be unified in a single group. The concise and encompassing term "infiltrative BCCs" can be used for these tumors. A binary classification of BCC into low-risk and high-risk subtypes on histopathological grounds alone is questionable; correlation with clinical factors is necessary to determine BCC risk and therapeutic approach.

Patient characteristics in tardive COVID-19 pseudoperniosis: a case series of 16 patients.

BACKGROUND: Acute pseudoperniosis (PP) has a recognized association with COVID-19 and tends to occur without cold precipitation in young, healthy patients, often without a clear history of COVID-19. These lesions usually resolve within 2 weeks and without long-term sequelae. In the early months of 2021, patients with delayed and protracted PP began to emerge. We have called this presentation 'tardive COVID-19 PP (TCPP)'. AIM: To consolidate and expand knowledge on TCPP, we describe the clinical characteristics, treatments and outcomes of 16 patients with TCPP who were reviewed by our outpatient dermatology service. RESULTS: The initial clinical manifestations were erythema, swelling and PP of the fingers in 56.2%, and of the toes in 31.2%, desquamation in 56.2% and acrocyanosis in 12.5%. Ten patients had eventual involvement of all acral sites. The median duration of symptoms was 191 days. Six patients reported close contact with a confirmed or suspected case of COVID-19, but only two had positive COVID-19 tests. Four patients experienced complete or almost complete resolution of symptoms, while the rest remain under active treatment. CONCLUSION: Unlike acute PP, TCPP has a protracted and delayed presentation that is typically associated with profound acrocyanosis. Patients with TCPP represent a new phenomenon that is part of the post-COVID-19 syndrome, with risk factors and pathophysiology that are not yet fully understood. Our data indicate that likely predisposing factors for developing TCPP include young age, a preceding history of cold intolerance and an arachnodactyloid phenotype. Anorexia, connective tissue disorders or sickle cell trait may also predispose to TCPP. In addition, low titre antinuclear antibody positivity, the presence of cryoglobulins, or low complement levels may represent further risk factors. Finally, prolonged low temperatures are also likely to be contributing to the symptoms.

Basal cell carcinoma of the vulva: treatment with Mohs micrographic surgery.

Vulval basal cell carcinomas (BCCs) are rare, representing < 5% of vulval malignancies and 1% of all BCCs. They often present with nonspecific symptoms and features that lead to large, poorly circumscribed and late-presenting lesions. Current and conventional treatments used to treat vulval BCC include cryotherapy, imiquimod and excision. However, recurrence rates as high as 20% have been reported with these treatments. Furthermore, there are no current clinical guidelines for their management. We present the first reported series of patients with vulval BCC treated with Mohs micrographic surgery (MMS). We report seven cases of vulval BCC treated with MMS at a tertiary referral centre over 3 years. Follow-up was performed at 3 months and up to 3 years. Our series demonstrates that there were no postoperative complications, functional sequelae or recurrences up to the 3-year follow-up. We therefore recommend that MMS should be considered in the management of vulval BCCs.

Inherited pulmonary cylindromas: extending the phenotype of CYLD mutation carriers.

BACKGROUND: Germline mutations in the tumour suppressor gene CYLD are recognized to be associated with the development of multiple cutaneous cylindromas. We encountered such a patient who presented with breathlessness because of multiple pulmonary cylindromas. OBJECTIVES: To search for clinical and radiological features of multiple pulmonary cylindromas in a cohort of 16 patients with CYLD mutations. METHODS: A retrospective case-note review was carried out in a tertiary dermatogenetics clinic where CYLD mutation carriers are reviewed on an annual basis. In-depth investigation was carried out for patients with pulmonary tumours. RESULTS: Four patients had radiological imaging of their lungs, of which two had multiple pulmonary cylindromas that were confirmed histologically. Serial computed tomography monitoring allowed for pre-emptive endobronchial laser ablation, preventing major airway obstruction and pulmonary collapse. CONCLUSIONS: Pulmonary cylindromas are an unrecognized, but infrequently symptomatic, aspect of the phenotype in these patients that can have implications for patient care. They should be considered in patients with a high tumour burden that present with respiratory symptoms, and where appropriate, monitored with serial imaging.