Abstract Introduction Small-cell lung cancer (SCLC) is an aggressive neuroendocrine carcinoma distinguished by rapid growth and early metastasis.4 Its pathogenesis is primarily marked by inactivation of the tumor suppressor genes TP53 and RB1, alongside frequent chromosomal rearrangements and a high mutation burden.2 In the context of immunosuppression following a solid-organ transplantation like a kidney, the possibility of reduced cytotoxic T-cell and natural-killer cell activity may further diminish immune surveillance, which can facilitate the unchecked growth of malignant cells, and accelerate the onset or progression of SCLC.3 Case Presentation 72-year-old male with history of End-Stage Renal Disease (ESRD) status post deceased donor kidney transplant 06/2025, hypertension, and 20 pack year smoking history who presented for worsening shortness of breath. He has been compliant with immunosuppressive treatment. He was hospitalized two weeks prior for a pneumonia with 1 liter of exudative fluid removed via thoracentesis at the time. No lab abnormalities were noted during his current admission. A CT Chest revealed a recurrent left-sided pleural effusion with persistent pleural based nodularity first identified during his previous hospitalization. He underwent bronchoscopy revealing significant mucosal erythema with pseudomonas growth on bronchioalveolar lavage. Thoracoscopy with biopsy and pleurodesis revealed numerous hard nodules adherent to the diaphragm. Two chest tubes were placed due to recurrent effusions requiring repeated thoracentesis. Biopsy results returned significant for small cell lung cancer. Required upgrade to ICU for increasing oxygenation requirements on high-flow nasal cannula, downgraded once chest tube was removed. Chest port placed for chemotherapy and patient subsequently discharged with outpatient follow-up with oncology. Discussion The emergence of SCLC within four months of kidney transplantation in this 72-year-old patient suggests that immunosuppressive agents such as tacrolimus and mycophenolate mofetil may have facilitated tumorigenesis through suppression of pulmonary immune surveillance. Prior studies have demonstrated that transplant recipients exhibit a higher incidence of lung malignancies, with an especially aggressive course observed among those receiving calcineurin inhibitors.1 Pulmonary malignancies in immunosuppressed patients often present atypically and can mimic infectious processes, appearing as nodular opacities and consolidations rather than discrete mass lesions, which may delay diagnosis and appropriate management. Conclusion This case highlights the need for an enhanced risk assessment and careful balancing of immunosuppression intensity in older patients with significant smoking histories as well as other cancer-predisposing risk factors. Ultimately, early detection and aggressive work-up are essential to optimizing treatment plans and mortality outcomes in these patients moving forward. This abstract is funded by: None
Stere et al. (Fri,) studied this question.