I'm a little worried, have been on Keto since Sept of last year, off a bit for Dec and began again since Jan. Had fasting blood work last week, results are:
Cholesterol= 358
LDL= 244
HDL= 105
Triglycerides= 45
Are these numbers something to worry about? have appointment with doctor to review next week.

Fantastic HDL and Trigs! You can chose or not to possibly adjust the types of fats to lower the LDL. Here is a great thread to help you decide what is best for you, follow Ken's links to what he did:

http://forum.lowcarber.org/showthread.php?t=468594

If your doctor panics (he shouldn't but his practice may have guidelines to follow)...ask for a CAC. http://forum.lowcarber.org/showthread.php?t=471526

See if you can get your doctor to order a particle size test for the LDL. The number is less important than the kind.

The fact that you took December off may be part of the jump. Your fat cells started filling back up, and, as you went back into ketosis, started emptying again, at a fast rate.

I had the same issue when after being in ketosis for about 6 months, my LDL was higher and total cholesterol was higher as well. First, I pay no attention to total cholesterol. Second, and as MickiSue and Janet recommend, get a more detailed blood test to see what's really happening with your metrics. What you want is a VAP or NMR Lipid panel that actually measures LDL and distinguishes between small and large particle size. This is important, as my LDL was high, but had no measurable small particle. The NMR Lipid panel also scores on IR resistance, which is useful.

Early on with LC and keto, some have higher lipid markers like LDL, as your body is actively burning fat and not glucose. Lots of fats in the blood for availability for fuel. The link Janet provided is an excellent way to make course corrections, but I wouldn't be too concerned about your LDL at this point until you can get more details as to size. Over time, total LDL is likely to come down.

Also, your Tri to HDL ratio is fantastic. This is one of the more important health markers, and ideally you want the ratio about 1.0 or lower. Your ratio is ideal!!!

Edited to add the link to the sticky at the top of this forum: http://forum.lowcarber.org/showthread.php?t=397715

I found coconut oil made my LDL go nuts when I was using it in coffee and such.

May I suggest this excellent short video, which by its very title addresses your question:

A/Prof. Ken Sikaris - 'Cholesterol - When to Worry'

Based on your TG of 45mg/DL (=0.50 mmol/L) and a chart shown in the video at (13:43 minutes) I would say you have nothing to worry about. TG correlates with the type of LDL. When TG is less than 89mg/dL (=1.0 mmol/L) it means you have close to zero small dense LDL, which is the stuff you don’t want to have.