The patient went on to have a biopsy of the left upper lobe mass. 

Histology

MICROSCOPIC DESCRIPTION: Sections show fibrous connective tissue infiltrated by nests and single tumor cells containing abundant pale cytoplasm, irregular polygonal nuclei with smooth chromatin and small nucleoli. No definite glandular or squamous differentiation is seen. No pigment is identified.

In immunohistochemical stains, the cells are CK7+, CK20-, p63-, CK5/6+ (weak), TTF-1+, napsin-A+,
CD56-, synaptophysin-, chromogranin-, ER-, GCDFP-.

DIAGNOSIS: Left upper lobe poorly differentiated adenocarcinoma of the lung.