Pathologic Findings in Bronchopulmonary Leukemic Infiltrates in Patients With Chronic Lymphocytic Leukemia

Chronic lymphocytic leukemia (CLL) is the most common lymphoproliferative disorder worldwide. Although thoracic complications are frequent in CLL, only limited data exists regarding these complications. Pleural, parenchymal, and airway disease may occur owing to CLL itself, treatment-related adverse events, typical or opportunistic infections, or from preexisting comorbidities. The etiology of parenchymal infiltrates is often attributed to pneumonia and can be difficult to properly identify without a diagnostic procedure.

We conducted a retrospective chart review of patients admitted from 2000 through 2016 with a diagnosis of CLL and abnormal radiography that underwent a bronchoscopy with biopsy, surgical lung biopsy, or transthoracic biopsies for nonresolving infiltrates after a course of antibiotics. We described the incidence of bronchopulmonary leukemic infiltrates (BPLI), describe other diagnosis achieved by the biopsy, and also describe the pathologic findings associated with BPLI in these patients.

There were 111 procedures performed on 98 patients that yielded a diagnosis in 82 patients. In 16 patients, no histologic or pathologic diagnosis was identified after the biopsy. BPLI was diagnosed in 32 (39%) cases. In 27 (85%) of 32 cases, the biopsies returned with only BPLI owing to CLL (without inflammation), whereas 5 (15%) of 32 cases showed concomitant acute or chronic inflammation.

Direct infiltration by leukemic cells may cause pulmonary symptoms and signs indistinguishable from infection. Biopsy is necessary to establish a definitive diagnosis, and physicians caring for these patients, including pathologists, should be aware of the clinicopathologic picture of BPLI to render an informative diagnosis.