Current Procedural Terminology, or CPT, codes serve as a standardized language for health care providers and payers across the United States. These numerical codes are how a physician communicates a specific medical service, procedure, or treatment to an insurance company for billing and reimbursement purposes. The system ensures that every service, from a simple office visit to a complex surgical intervention, is uniformly reported regardless of the location or physician performing it.
Defining Diagnostic Hysteroscopy
The procedure known as hysteroscopy involves using a thin, lighted telescope, called a hysteroscope, which is inserted through the vagina and cervix to visualize the inside of the uterus. This method provides a direct, magnified view of the uterine cavity and the openings to the fallopian tubes, known as the tubal ostia. The primary goal is to visually inspect the endometrial lining for abnormalities.
CPT code 58558 is formally defined as a surgical hysteroscopy, specifically encompassing the surgical component of “with sampling (biopsy) of endometrium and/or polypectomy, with or without D&C.” While it includes a diagnostic step of visualization, the purely diagnostic code is CPT 58555, used when only viewing and no tissue manipulation occurs. CPT 58558, therefore, refers to a procedure that simultaneously diagnoses and treats identified pathology, making it a comprehensive intervention.
Clinical Reasons for the Procedure
A physician typically recommends the procedure represented by CPT 58558 to investigate and treat specific causes of abnormal uterine bleeding (AUB). AUB includes heavy menstrual periods, bleeding that occurs between cycles, or any bleeding experienced after menopause. In these cases, direct visualization is necessary to identify the source of the hemorrhage that may not be apparent on ultrasound or other imaging.
The procedure is also frequently indicated for diagnosing and treating structural abnormalities within the uterine cavity. Common targets include endometrial polyps, which are localized overgrowths of the uterine lining, and submucosal fibroids, which are benign muscle tumors that bulge into the cavity. Hysteroscopy allows for the precise location and removal of these growths, which are often the underlying cause of a patient’s symptoms.
In the context of reproductive health, CPT 58558 may be used in an infertility workup or after recurrent miscarriage. The visual inspection helps to identify congenital uterine malformations, such as a uterine septum, or acquired conditions like intrauterine adhesions (Asherman syndrome), which can interfere with embryo implantation or lead to pregnancy loss. The procedure can also be used to locate and retrieve a lost or embedded intrauterine device (IUD) whose strings are not visible in the cervix. Performing a targeted biopsy during the same session provides a definitive tissue diagnosis for any suspicious areas.
Patient Experience and Procedure Steps
The hysteroscopy procedure is commonly performed in an outpatient clinic or an operating room, depending on the complexity and the need for anesthesia. The patient is typically positioned on their back with their feet in stirrups (dorsal lithotomy). The physician then gently inserts the hysteroscope through the cervical canal and into the uterus.
To allow for clear visualization of the uterine walls, the cavity must be gently expanded, or distended, using a specialized medium. Normal saline (sterile salt water) is the most common distension medium because it is safe and provides a clear view. Carbon dioxide gas is also an option, but it has been associated with a higher incidence of side effects like shoulder-tip pain or vasovagal reactions.
For CPT 58558, once the abnormality is identified, small instruments are passed through the hysteroscope to perform the surgical part of the procedure, such as removing polyps or obtaining a biopsy. The duration of the entire process is generally brief, often lasting only 15 to 30 minutes. Following the procedure, patients may experience mild to moderate cramping and light vaginal spotting for a few days. Recovery is fast, with most individuals resuming normal activities within 24 hours.
Billing Context: The “Separate Procedure” Designation
The CPT code description for a purely diagnostic hysteroscopy (CPT 58555) contains the phrase “separate procedure,” which has a specific meaning in medical billing. This designation indicates that the procedure is not typically reported or billed separately when it is performed as an integral part of a more extensive procedure in the same anatomical area. This rule prevents the duplicate billing of a preliminary step when that step is inherently necessary for the main service.
In the context of CPT 58558, the purely diagnostic step of visualization is considered a prerequisite for the surgical component of the code. Therefore, if a physician performs a diagnostic hysteroscopy, identifies a polyp, and immediately removes it in the same session, they would only bill the comprehensive surgical code, CPT 58558. The diagnostic code 58555 would be “bundled” into the payment for the surgical code. CPT 58555 is only billed when the diagnostic inspection is the only procedure performed or when it is performed at a completely separate encounter.