Langerhans' cell histiocytosis can manifest as three distinct clinicopathologic entities: acute disseminated Langerhans' histiocytosis (previously known as Letterer-Siwe disease), unifocal Langerhans' cell histiocytosis (previously known as eosinophilic granuloma).
average handle time (AHT) Average handle time (AHT) is a call center metric for the average duration of one transaction, typically measured from the customer's initiation of the call and including any hold time, talk time and related tasks that follow the transaction. AHT is a prime factor when deciding call center staffing levels.
The time for usual service refers to the typical/average time units associated with the companion evaluation and management service as noted in the CPT code. Each additional 30 minutes of direct face-to-face patient contact following the first hour of prolonged services may be reported by CPT code 99355.