C80-41 A Rare Case of Pulmonary Carcinoid Tumor in an Older Patient With Neurofibromatosis Type 1

Abstract Introduction Pulmonary carcinoid tumors are rare, well-differentiated neuroendocrine neoplasms. Their occurrence in individuals with neurofibromatosis type 1 (NF1) is extremely uncommon, with only isolated case reports describing this association. This case highlights the diagnostic challenges and clinical relevance of identifying pulmonary carcinoid tumors in NF1 patients, particularly in patients with complex comorbidities. Description of Case An 82-year-old female who is a non-smoker, with NF1, chronic lymphocytic leukemia (CLL) in remission, hypogammaglobulinemia, and prior schwannoma resection was evaluated for progressively enlarging pulmonary nodules. Initial CT imaging in 2020 revealed two 5-mm nodules in the left upper lobe and lingula. Subsequent contrast-enhanced CTs demonstrated several more left upper lobe and lingular nodules. By 2025, the dominant left upper lobe nodule measured 13 mm, with additional nodules measuring up to 8 mm in the left upper lobe and 6-8 mm in the lingula. PET-CT in 2023 also demonstrated increasing hypermetabolism of the dominant nodule (SUVmax 5.7). Given gradual growth and metabolic activity, robotic-assisted bronchoscopy with radial EBUS and fluoroscopic guidance was performed in October 2025. Transbronchial biopsies confirmed a typical pulmonary carcinoid tumor without necrosis or atypia. Adjacent nodules were benign, bronchoalveolar lavage cytology was negative, and lymph node cytology showed only reactive changes. Flow cytometry confirmed no CLL recurrence. The patient remained clinically stable without carcinoid syndrome and was referred to a multidisciplinary team to determine optimal management, balancing surgical candidacy with age and comorbidities. Discussion NF1 is associated with an increased risk of certain malignancies, including optic nerve gliomas, malignant peripheral nerve sheath tumors, and pheochromocytomas. However, pulmonary neoplasms are rarely reported in association with NF. Moreover, while gastrointestinal carcinoids are more frequently reported in NF1, pulmonary carcinoids are distinctly uncommon. Slow nodule growth, metabolic activity, and bronchoscopic biopsy were key to diagnosis. Although NF1-associated pulmonary carcinoids may exhibit variable behavior, treatment principles mirror sporadic cases, with surgical resection remaining the standard approach for localized disease. This case expands the spectrum of NF1-associated neoplasms, showing that clinical vigilance and individualized management strategies are the cornerstone of management in these patients with complex histories. This abstract is funded by: None