Abstract Introduction Adenocarcinomas account for approximately 40-50% of all primary lung cancers. They usually follow an indolent course, and present unilaterally. Bilateral, rapidly progressive forms are uncommon and may radiographically resemble organizing pneumonia, edema, or infection. Secondary solid tumors occur in only 2-6% of long-term hematopoietic cell transplant (HCT) survivors, usually after a latency exceeding five years. We describe a post-HCT patient with subacute respiratory failure whose imaging rapidly evolved over weeks from multifocal opacities to diffuse consolidations, ultimately revealing mucinous adenocarcinoma. Case Description A 75-year-old woman with DM type II, HFimpEF, and acute myeloid leukemia (AML) in remission after cord-blood transplantation (2015) was admitted twice to the hospital in four weeks for progressive dyspnea and cough refractory to antibiotics, diuretics, and corticosteroids. CT imaging showed diffuse interlobular septal thickening with patchy ground opacities bilaterally in the lower lobes. Initial bronchoscopy revealed neutrophil-predominant inflammation (29%) without organisms or malignant cells (CD4:CD8 = 0.7). Extensive infectious and autoimmune testing was unrevealing; NT-proBNP decreased (693 → 485 pg/mL), arguing against volume overload. With worsening of symptoms, a CT scan was repeated, revealing interval development of diffuse ground glass opacities in all five lobes with a lower lobe preponderance. PET/CT demonstrated FDG-uptake in the areas of consolidation and in the hilar and mediastinal lymph nodes. EBUS-guided biopsies revealed mucinous adenocarcinoma (CK7+, TTF-1−, p40−, PD-L1 1%) across multiple nodal stations. Molecular testing was negative for EGFR, ALK, KRAS, and FISH rearrangements. The patient unfortunately developed worsening respiratory failure requiring rescue non-invasive ventilation and ultimately transitioned to comfort-directed care. Discussion Bilateral presentation of invasive mucinous adenocarcinoma is uncommon, and the apparent rapid progression in this case (usual volume doubling time is 200-400 days) was striking. Several factors may explain her presentation. Post-transplant immune dysregulation after prior cord-blood transplantation and exposure to alkylating agents may have impaired tumor surveillance, allowing accelerated spread. The TTF-1 negative phenotype is associated with shorter doubling times. Aerogenous spread, characteristic of pneumonic-type mucinous adenocarcinoma, enables seeding of adjacent lobules, producing abrupt increases in apparent disease burden. Diagnostic uncertainty was compounded by coexisting heart failure, which initially masked the malignant process. This case demonstrates how adenocarcinoma presenting with bilateral opacities can be challenging to diagnose, and the role of biopsy when radiographic evolution defies expectation. This abstract is funded by: none
Hodge et al. (Fri,) studied this question.