Schnitzler syndrome refractory to anakinra: successful treatment with canakinumab.

Schnitzler syndrome (SchS) is a rare autoimmune and inflammatory disease mediated by interleukin-1 beta (IL-1ß). Recurrent monoclonal gammopathy and chronic urticarial rash are the symptoms required for diagnosis according to the Strasbourg criteria. The low prevalence of this syndrome (around 300 cases have been reported) and confusion with other inflammatory disorders may delay the diagnosis for up to 5 years. Although the most effective treatment for SchS is anakinra, some patients do not respond to this treatment. We report a case of SchS in a 64-year-old woman with multiple episodes of fever, severe rash, erythema, arthralgia and dyspnea. The patient was successfully treated with canakinumab after anakinra intolerance and failure of colchicine, prednisone, methotrexate and dapsone. After the first dose of canakinumab the skin wounds rapidly improved and the patient did not require any concomitant treatments. The cause of SchS is still unknown and a differential diagnosis is recommended, especially with adult-onset Still´s disease due to their similar symptoms. Canakinumab, a specific anti-IL-1ß antibody, blocks its binding to receptors, thereby preventing IL-1ß-induced gene activation and production of inflammatory mediators. Canakinumab has proven to be an effective drug in SchS, providing an alternative to anakinra.

Melanocytic Matricoma With Atypical Histopathological Features: A Case Report of an Extremely Rare Entity and Review of the Literature.

ABSTRACT: Melanocytic matricoma with atypical features is a rare, biphasic adnexal neoplasm displaying hair matrix differentiation, with only 3 reported cases worldwide. Generally, the lesion comprised a solid matrical and supramatrical cell proliferation, admixed with intermediate cell aggregates with sparse anucleated "shadow cells" and a prominent pigmented melanocytic hyperplasia. We report the case of a 78-year-old man with a slow-growing crusted lesion on the frontal left scalp, which in a matter of 1-2 months became a 0.6 cm well-defined, black purplish exophytic nodule. Histopathologically, the lesion presented a well-circumscribed border with a nodular dermal growth pattern, presenting different architectural features varying from benign pilomatricoma-like changes to atypical features such as moderate-to-high nuclear pleomorphism in both basaloid (matrical/supramatrical) and epidermal (keratinous) components. Strong nuclear and cytoplasmic positivity for ß-catenin was observed in matrical cells, whereas prominent cytoplasmic membrane positivity for Melan-A in dendritic melanocytes. Owing to the evidence of atypical cytological features, we propose the "atypical/borderline" category of melanocytic matricoma as part of a possible spectrum among matrical neoplasms. Pathologists should be aware of any atypical histopathological features while reporting cases due to their potential malignant transformation.