LabCorp ($LH) grew revenue slightly but faced flat net earnings during its 2013 third quarter in the face of continued reimbursement challenges. The North Carolina diagnostics giant said net earnings hit $148.3 million during the quarter, essentially flat over the same period in 2012. LabCorp booked more than $1.46 billion in revenue, however, a 3% jump over the 2012 third quarter. LabCorp attributed the revenue results to higher testing volume and growth in its toxicology business, balanced by government payment reductions and insurance reimbursement issues involving molecular pathology codes. Item