A 66-year-old man with a 50-pack-year smoking history and severe chronic obstructive pulmonary disease (COPD) presented to our clinic with a new right upper lobe (RUL) pulmonary nodule and a chronic left lower lobe (LLL) consolidation on screening computed tomography (CT). His pulmonary function tests (PFTs) showed airflow obstruction with an FEV1 of 2.58 L (81% predicted). The LLL consolidation was evident on a chest radiograph 6 months before his current presentation, and the lesion had been biopsied by his local pulmonologist via conventional bronchoscopy with no evidence of malignancy.
The patient reported a 45-pound weight loss over the course of three months, as well as a recent hospitalization for severe hyponatremia (109 mEq/L). Upon physical examination, the patient was noted to be cachectic, with bilateral decreased air entry. CT of the chest showed a stable LLL consolidation along with a 9 x 21 mm subsolid lesion in the RUL. Navigational bronchoscopy and biopsy of the RUL lesion revealed squamous NSCLC with positive CK5, p63, and TTF-1 markers (Figures 1(a)-1(c)). The LLL consolidation was not sampled during this procedure, as it was located on the contralateral lung, was noted to be stable for 6 months based on a prior chest radiograph, and had been analyzed after a previous bronchoscopy with cytology and transbronchial lung biopsies without evidence of malignancy. A staging positron emission tomogram (PET) done after the navigational bronchoscopy once a malignant diagnosis was confirmed showed FDG avidity in the RUL lesion (SUV 2), along with an FDG-avid left infrahilar mass (SUV 11) within the LLL consolidation (Figure 1(d)). The absence of enlarged or FDG-avid mediastinal adenopathy made the diagnosis of a second primary cancer very likely. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) of the left infrahilar mass revealed a cluster of cells with minimal cytoplasm and small nuclei with nuclear cytoplasmic molding (Figures 1(d)-1(f)).
Immunohistochemical markers were consistent with an undifferentiated SCLC that was positive for CAM 5.2, TTF-1, CD56, and synaptophysin and negative for p63 and CK5 (Figure 1). The final diagnosis was a right-sided Stage I NSCLC (squamous) and a left-sided limited SCLC. Chemotherapy was initiated with etoposide and cisplatin, along with concurrent radiation for the left-sided SCLC. Given the overall poor survival associated with small cell carcinoma, surgery including segmentectomy was not a therapeutic option for the Stage I right-sided squamous cell carcinoma. Stereotactic body radiation therapy (SBRT) was then initiated for the squamous cell cancer. Despite lower rates of recurrence after segmentectomy compared to SBRT, the likelihood of recurrent SCC driving survival in this patient with concurrent SCLC was low. The patient's hyponatremia has since resolved, and his surveillance PET scan showed him to be recurrence-free at 1 year.