A 12-year-old female with a known diagnosis of systemic lupus erythematosus presents with acute-onset hemoptysis, dyspnea, and new diffuse alveolar infiltrates on her chest radiograph. A lung biopsy is performed to guide aggressive immunomodulatory therapy. Which histopathologic finding is most frequently encountered in diffuse alveolar hemorrhage (DAH) associated with this underlying condition and is associated with a negative prognosis?