An autopsy case of anti-MDA5 antibody-positive amyopathic dermatomyositis with an initial manifestation of panniculitis on the left upper arm.

A 53-year-old man was presented with refractory panniculitis on the left upper arm that had persisted for 10 months. The patient was diagnosed with lupus profundus, wherein oral glucocorticoid therapy was initiated. Four months prior, ulceration was observed in the same area. Dapson was administered instead, scarring the ulcer but enlarging the panniculitis. Five weeks earlier, he developed a fever, productive cough, and dyspnoea. Three weeks earlier, a skin rash was observed on the forehead, left auricle posterior to the neck, and extensor aspect of the left elbow. Chest computed tomography showed pneumonia in the right lung, after which the patient's dyspnoea worsened. The patient was admitted and diagnosed with anti-MDA5 antibody-positive amyopathic dermatomyositis (ADM) based on skin findings, hyperferritinaemia, and rapidly progressive diffuse lung shadows. Glucocorticoid pulse therapy, intravenous cyclophosphamide, and tacrolimus were initiated, and later, plasma exchange therapy was combined. However, his condition worsened and required management with extracorporeal membrane oxygenation. The patient expired on day 28 after hospitalisation. An autopsy revealed hyalinising to fibrotic stages of diffuse alveolar damage. Strong expression of myxovirus resistance protein A was observed in three skin biopsy specimens from the time of initial onset, consistent with ADM. Anti-MDA5 antibody-positive ADM not only manifests typical cutaneous symptoms, but also rarely occurs with localised panniculitis, such as in the present case. In patients with panniculitis of unknown aetiology, the possibility of initial symptoms of ADM should be included in the differential diagnosis.

Xp11.2 translocation renal cell carcinoma with SFPQ/PSF-TFE3 fusion gene: A case report with unusual histopathologic findings.

Xp11.2 translocation renal cell carcinoma (Xp11tRCC) is a subtype of renal cell carcinoma (RCC) characterized by chromosomal rearrangement of the region harboring the transcription factor for immunoglobulin heavy-chain enhancer 3 (TFE3). Xp11tRCCs comprises 20% to 40% of RCCs of children and adolescents and is generally associated with good prognosis. However in adult, the incidence of this tumor is relatively low (1% to 4%), suggesting a more aggressive course. TFE3 gene is fused by translocation to numerous partner genes, and definitive molecular characteristics can be difficult to verify. In this case report, we presented a case of Xp11tRCC with the SFPQ/PSF-TFE3 chimeric gene. The fusion gene was detected by 5'-rapid amplification of cDNA ends (5'RACE). The tumor was found to be in an advanced stage with multiple lymph node metastases. The histological characteristics of the tumor were different from those of XP11tRCC with other more frequently detected fusion genes.