New System Classifies Causes of Abnormal Uterine Bleeding

Laurie Barclay, MD

June 07, 2011

June 7, 2011 — The International Federation of Gynecology and Obstetrics (FIGO) has approved a new classification system (PALM-COEIN) for causes of abnormal uterine bleeding (AUB) in nongravid women of reproductive age. The new system, which is published in the June issue of the International Journal of Gynecology & Obstetrics, should facilitate basic science and clinical research, as well as the practical, rational, and consistent application of medical and surgical treatments.

Of the 9 categories in the new FIGO classification system (PALM-COEIN), the first 4 are defined as visually objective structural criteria (PALM: polyp, adenomyosis, leiomyoma, and malignancy and hyperplasia). The second 4 are unrelated to structural abnormalities (COEI: coagulopathy, ovulatory dysfunction, endometrial, and iatrogenic), and the final category is for entities that are not yet classified (N).

"There has been general inconsistency in the nomenclature used to describe ...AUB in reproductive aged women, and there is a plethora of potential causes—several of which may coexist in a given individual," said lead author Malcolm G. Munro, MD, FRCS(c), FACOG, professor of obstetrics and gynecology at the David Geffen School of Medicine, UCLA, and director of gynecologic services, Kaiser Permanente, Los Angeles Medical Center in California, in a news release.

"It seems clear that the development of consistent and universally accepted nomenclature is a step toward rectifying this unsatisfactory circumstance. Another requirement is the development of a classification system for the causes of AUB, which can be used by clinicians, investigators, and even patients themselves to facilitate communication, clinical care, and research."

After a thorough 5-year review process beginning with workshops in 2005, a group of clinician-investigators from 17 countries on 6 continents who had substantial experience in AUB research developed and revised a draft system that was distributed for comments. The PALM-COEIN classification system was then discussed at a meeting held in association with the 2009 FIGO World Congress in Cape Town, South Africa, and subsequently approved by the FIGO Executive Board as a FIGO classification system.

The PALM Categories

The PALM categories (polyp, adenomyosis, leiomyoma, and malignancy and hyperplasia) refer to discrete (structural) entities that can be measured visually with imaging techniques, such as sonography and/or histopathology testing. The "polyp" category lends itself to the development of a subclassification for clinical or investigative use based on a combination of variables, including polyp dimension, location, number, and morphologic and histologic features. The "leiomyoma" category is subdivided into patients with at least 1 submucosal myoma and those with myomas that do not affect the endometrial cavity.

Within the "malignancy and hyperplasia" group, it was proposed that malignant or premalignant lesions, such as atypical endometrial hyperplasia, endometrial carcinoma, and leiomyosarcoma, be categorized as such within the major category, but further described with use of existing World Health Organization and FIGO classification and staging systems.

In contrast to the PALM group, the COEIN group (coagulopathy, ovulatory dysfunction, endometrial, iatrogenic, and not yet classified) includes nonstructural entities that are not defined on imaging or histopathology testing. The "iatrogenic" category refers to AUB associated with the use of exogenous gonadal steroids, intrauterine systems or devices, or other systemic or local agents.

Practical, Feasible System

"There is no existing classification of the causes of these common gynecologic symptoms that allows good communication between practicing clinicians and researchers, and which encourages focus on the optimal approaches to modern management," said FIGO chief executive Hamid Rushwan. "Therefore, FIGO is pleased to have a role in facilitating the use of this ground-breaking new classification worldwide."

The diagnosis of chronic AUB requires unpredictability, excessive duration, abnormal volume, and/or abnormal frequency of menses for at least the previous 3 months. Structured history should determine ovulatory function, potential related medical disorders, medications, and lifestyle factors that might contribute to AUB.

Subsequent appropriate investigation may be based in part on the future fertility desires of the patient. Ancillary testing should include hemoglobin and/or hematocrit, testing for conditions that could contribute to an ovulatory disorder (thyroid function, prolactin levels, and serum androgen levels), and either referral to a hematologist or appropriate tests for von Willebrand's disease if a structured history suggests coagulopathy.

The developers of the new system intended it for practical and feasible use by clinicians in most countries worldwide to readily and consistently classify patients with AUB. Because of a lack of availability in many countries, the use of magnetic resonance imaging (MRI) for characterization of structural lesions of the uterus was not feasible; therefore, use of MRI was not included as a mandatory tool to classify patients with chronic AUB.

However, clinicians should continue to use MRI if it is considered to be necessary and is available, and they should use the results of MRI scans to determine the presence or absence of adenomyosis when classifying a patient according to the present PALM-COEIN system.

Regular Modifications Needed

"It is recognized that the system will require periodic modification and occasional substantial revision depending on advances in knowledge and technology, and increasing availability of investigative options across geographic regions," the study authors write. "Consequently, we recommend a scheduled systematic review of the system on a regular basis by a permanent committee of an international organization such as FIGO, which has already endorsed the establishment of a suitable ongoing Working Group on Menstrual Disorders."

In an accompanying special editorial, by Drs. Munro, Hilary O. D. Critchley, and Ian S. Fraser, they further reemphasize that "the FIGO classification is regarded as a flexible 'living' document that should undergo review and consideration for modification at regular intervals. It is suggested that discussion of the practical use and clarity of the classification should initially occur at 3-yearly intervals—in line with each FIGO World Congress."

Some of the study authors have acted as consultants for, given lectures for, and received honoraria from Bayer Schering Pharma, which partly funded this initiative. Many other organizations and companies contributed in direct or indirect ways to the development of this process.

Int J Gynecol Obstet. 2011;113:3-13. Abstract


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