[James Calum]

I'll do this Season by Season, listing the full name of the POTW (if known), age (if given) and final diagnosis. Part of the info you only get from screencaps and/or the scripts/transcripts. Here's the list for Season 8:

8x1 - Nick (30ies), mastocytosis
8x2 - Steve Weathers (lungs only) (18) & Vanessa St. Germain (~45), eosinic pneumonitis & emphysema
8x3 - Benjamin Byrd (~40ies), Plummer's disease
8x4 - Thad Burton (55 - 65), hyperviscosity syndrome due to rheumatoid arthritis
8x5 - Bob Harris (38), kawasaki's syndrome
8x6 - Ben Parker (16), syphillis, Herxheimer reaction
8x7 - Iris Mettery (14) & Drew Lemaine (dead at 4 or 5), mutiple personality disorder due to trauma, chorion carcinoma & Alport syndrome
8x8 - Tommy Fortunato (40), diphteria
8x9 - Andres Tavares (40 - 45), Reye syndrome
8x10 - Callie Roberts (or Rogers) (16), ascariasis
8x11 - Bill Koppelman (32), tumor lysis syndrome
8x12 - Moira Parker (30 - 35), giant cell arteritis (Horton's)
8x13 - Joe Reese (38), syílent thyroiditis polyglandular autoimmune syndrome type III
8x14 - Will Westwood (20 - 25), mucormycosis
8x15 - Brant Macklin (20), typhus
8x16 - Bobby Hatcher (22), Miller-Fisher syndrome, mononucleosis
8x17 - Henry Peck (35), amoebic meningitis
8x18 - Lue Cheng (8), patent ductus arteriosus
8x19 - Emily Lawson (6), atrial myxoma
8x20 - Dr. Peter Treiber (35), hypothyroidism (caffeine from energy drinks and triclosan from soap)
8x21 - Derrick Morrell (19), persistent stapedial artery
8x22 - Oliver (40ies), autoimmune reaction to biological infiltrate