So I was between L4 and S1 radiculopathies on this one and couldn't remember the sensory/motor/reflex losses that differentiated the two. Here's a summary (including L5 for completeness)
With treatment adherence, most HIV-positive individuals will die of the same things as the rest of us: the American way of life.
Pt has malignant effusion, which you would expect to be exudative. Exudative is characterized by protein pleural/serum > 0.5 LDH pleural/serum >0.6, and a LDH >2/3 upper limit of normal. So that would be increased protein or increased LDH, LDH is not an answer, so easy to rule out.
This is Paget-Schroetter disease
An upper extremity thrombosis triggered by extreme activity.
He's a fit young jackhammerer just trying to do his jackhammer thing