BI15 (P16) Cutaneous renal cell carcinoma metastasis with scrofuloderma as the initial presentation of metastatic renal cell carcinoma: a diagnostic challenge

Abstract Renal cell carcinoma (RCC) with cutaneous metastasis is uncommon and accounts for approximately 3–5% of metastatic RCC, an unfavourable prognosis. We present unusual difficult case advanced RCC presenting initially scrofuloderma, identical morphology the lesions. It also highlights importance dermatologists in early diagnosis management such cases. A 50-year-old man presented gradually progressive, multiple erythematous discharging nodules over right side his neck 3 months’ duration. He described a weight loss 10 kg, intermittent undocumented fever headache two episodes uninvestigated transient haematuria last 6 months. had received courses antibiotics without any relief. skin biopsy immunohistochemistry confirmed primary left involving brain as well. total nephrectomy was done he started on lenvatinib, everolimus radiotherapy, following which there suboptimal response developing similar nodular lesions axilla chest wall, puckered crusted plaque lateral abdomen 1 week post-treatment. Follow-up at 8 weeks revealed significant lesions; however, new did not respond, dermatology consultation sought again. from scrofuloderma. Tissue polymerase chain reaction culture were positive mycobacterium tuberculosis. diagnosed having scrofuloderma daily isoniazid, rifampicin, ethambutol pyrazinamide 2 months followed by isoniazid rifampicin 4 well-healed lesions, systemic symptoms discharge abated. The healed completely. Here, we interesting coexisting initial manifestation posing diagnostic challenge due to morphology. On this background, recurrence first possibility considered delay led morbidity our patient, emphasizing role high index suspicion conditions masquerading metastasis, well lower threshold biopsy, may improve prognosis dramatically.