BI25 A change of heart: metastatic cutaneous squamous cell carcinoma in a renal transplant recipient

Abstract

Cutaneous squamous cell carcinoma (cSCC) is the most common malignancy in solid organ transplant recipients (SOTRs). It carries a metastatic risk of approximately 2–5% in the population as a whole, with this risk increasing to 10–20% in high-risk lesions and immunosuppressed SOTRs. A 65-year-old man underwent right-sided renal transplantation in 2015 for focal segmental glomerulo­sclerosis and was maintained on tacrolimus and prednisolone. He had a history of nasopharyngeal non-Hodgkin lymphoma (treated with R-CHOP chemoradiation in 2013) and multiple nonmelanoma skin cancers requiring repeated dermatological intervention. In April 2024 three moderately differentiated cSCCs were excised in quick succession from the dorsal left hand, left cheek and chin. Of note, the chin cSCC had a narrow deep margin of 0.3 mm and the patient opted for surveillance instead of further surgery. Acitretin and nicotinamide chemoprevention were discussed but not initiated. In early 2025 our patient reported chest pain, dyspnoea and weight loss. Blood tests showed microcytic anaemia and an elevated B-type natriuretic peptide. Computed tomography (CT) pulmonary angiogram excluded an embolism but revealed an enlarging right-ventricular septal mass. Cardiac magnetic resonance imaging demonstrated a 3 × 5 × 4-cm fluorodeoxyglucose-avid right-ventricular apical lesion, and endomyocardial biopsy confirmed metastatic cSCC. No other visceral disease was identified on positron emission tomography–CT. Multidisciplinary discussion considered immune checkpoint blockade vs. cytotoxic chemotherapy. Programmed death-1 inhibitors carry approximately 25% risk of renal allograft rejection. Balancing graft preservation, oncological control and patient preference, he was commenced on carboplatin with paclitaxel. Cycle one of chemotherapy was complicated by neutropenic sepsis; he proceeded with a reduced dose and completed four cycles without further complication. Clinically he has gained weight and his most recent interval CT of the thorax, abdomen and pelvis shows a reduction in the mass at the cardiac apex. Cardiac metastasis from cSCC is exceptionally uncommon. This case underlines the aggressive potential of cSCC in chronically immunosuppressed patients and the importance of meticulous dermatological surveillance.