Critical Evaluation of PALM-Coein Classification

Author Information

Parulekar SV.
(Professor and Head, Department of Obstetrics and Gynecology, Seth G S Medical College & KEM Hospital, Mumbai, India.)

FIGO has been doing a lot of work on gynecologic cancers. The staging systems are revised every few years over the past 85 years, and are evidence based. It came out with a new classification system  called PALM-COEIN for causes of abnormal uterine bleeding in nonpregnant women of reproductive age in 2011. It was indeed a remarkable effort. There was initially a multistage development process using a modification of the  RAND/UCLA Delphi  process to evolve a survey to elicit panelists’ beliefs about the classification. The 39 clinician–investigators panelists from over 17 countries met for 2.5 days in Washington, USA. They brainstormed and developed new survey questions. A short Delphi system was used again. The draft system developed was  discussed  at  a  meeting  held  in association  with  the  2009  FIGO  World  Congress  in  Cape  Town, South  Africa.  It was modified and then presented to more than 700 FIGO attendees and finally approved.

PALM-COEIN Classification of Abnormal Uterine Bleeding

P: Polyp
C: Coagulopathy
A: Adenomyosis
O: Ovarian dysfunction
L: Leiomyoma

E: Endometrial
Pedunculated intracavitary

<50% intramural

>50% intramural

O- Other
Contacts endometrium, 100% intramural


Subserosal >50% intramural

Subserosal <50% intramural

Subserosal pedunculated

Other (specify: cervical, parasitic)

Hybri leiomyomas

Impact both endometrium and serosa

M: Malignancy and hyperplasia
I: Iatrogenic

N: Not yet classified
It was stated that the need for the classification arose due to existing nomenclature which was confusing and inconsistently applied, and also the lack of standardized methods for investigation and categorization of the various potential etiologies. This was believed to lead to deficiency in diagnosis and management. This classification was considered a necessary step in the evolution of collaborative research and evidence-based management of the patients. There are many aspects of this which are confusing. Abnormal uterine bleeding is a symptom for which there are a large number of causes. Such causes are extensively listed and discussed in textbooks of gynecology. Dividing them into two broad groups – PALM and COEIN – based on visually objective structural criteria and criteria unrelated to structural abnormalities did not serve any great purpose. After all, a final diagnosis in a given case is never limited to what is seen on gross. After careful clinical evaluation and appropriate investigations, a diagnosis is reached. Then appropriate treatment is given. Putting the causes into such groups does not change the process in any way. There should not be any reason to deviate from the procedure when such a classification is not used, and I believe no clinician deviates in such a way. One can admit that this system has made remembering the causes easy for students, since it is in the form a mnemonic that uses common words palm and co(e)in, supplemented by pictures of a palm and a coin. There has been confusion in using terms to describe the type of abnormal uterine bleeding, because different clinicians and authors use different terms. But that is issue can be handled by recommending standard terminology. There has been no confusion in the names of the causes in the past. The terms polyp, adenomyosis, leiomyoma, malignancy, hyperplasia, coagulopathy, ovulatory dysfunction, endometrial, and iatrogenic were used in the past and are used in the PALM-COEIN system too. The reason of clubbing malignancy and hyperplasia together is inexplicable, other than that if they were separated, the mnemonic would not work. Putting such diverse conditions together will in no way help accurate nomenclature, accurate categorization, comparison of different studies, and generation of data to be used for evidence based recommendations. The list is incomplete. The last category ‘not yet classified’ is supposed to include all conditions which do not fit in the previous categories. That would not help achieve the objectives which are listed above, since precision in statistical work demands comprehensive categorization of variables. Conditions not listed at all include functioning ovarian tumors, One condition has been extensively subcategorized – leiomyoma. However the same has not been done about the others. It makes one wonder if there is something special about leiomyomas. Types of polyps should be listed, and so also their number, location and size. Adenomyosis may be subcategorized into global, anterior, and posterior (the latter two being adenomyomas). Malignancies involving the endometrium should be classified depending on their histopathology, before applying the FIGO classification of malignancies to them. Hyperplasias should be divided into simple and complex. All coagulopathies should have been included. Ovarian dysfunction should be subdivided based on its cause. The category ‘endometrial’ is confusing. Its hyperplasia and malignancy are included in ‘M’ category, polyps in ‘P’ category, and proved conditions like tuberculosis and vascular malformations are not included citing lack of evidence. Abnormal uterine bleeding can occur due to self medication with hormonal preparations. It is evident that such extensive classification would make putting it in the form recommended by PALM-COEIN quite cumbersome. But scientific approach to any problem is often complicated, and the detail should not be sacrificed for ease of application. After all, the subcategories would have to be put separately anyway, defeating the purpose of having an accurate, all-encompassing classification. Nothing is wrong with stating the final diagnosis as a single entity or a combination of different entities, instead of putting it in PALM-COEIN format with zeroes for those categories which are not applicable.

It is not surprising that the PALM-COEIN classification has not been adopted by most clinicians. What is surprising is that FIGO has not revised it in more than 5 years, though it was stated that there would be scheduled systematic review and revision of the system.

The following classification of the symptoms of abnormal uterine bleeding is recommended.

  1. Abnormal uterine bleeding
  2. Heavy menstrual bleeding
  3. Prolonged menstrual bleeding: ≥10 days of bleeding in one episode.
  4. Heavy and prolonged menstrual bleeding
  5. Intermenstrual bleeding
    1. Intermenstrual midcycle bleeding
    2. Intermenstrual  premenstrual bleeding
    3. Intermenstrual postmenstrual bleeding
  6. Irregular menstrual bleeding: range of varying lengths of bleeding-free intervals >17 days within one 90-day reference period.
  7. Scanty menstrual bleeding
  8. Infrequent menstrual bleeding: <2 episodes of bleeding in a 90-day reference period.
  9. Frequent menstrual bleeding: >4 episodes of bleeding in a 90-day reference period.
  10. Absent menstrual period: absence of bleeding/spotting during the reference period.
The following classification of the causes of abnormal uterine bleeding is recommended.
  1. Uterine
    1. Myometrial
                                                               i.      Leiomyoma
                                                             ii.      Adenomyosis
    1. Endometrial
                                                               i.      Hyperplasia
1.      Simple
2.      Complex
3.      Atypical
                                                             ii.      Polyp (state type)
                                                            iii.      Malignancy
1.      Carcinoma
2.      Sarcoma (state type)
3.      Choriocarcinoma
4.      Metastatic
                                                           iv.      Inflammation (state type e.g. tuberculosis)
                                                             v.      Vascular malformation
                                                           vi.      Synechiae
  1. Ovarian
    1. Anovulation (state cause)
    2. Estrogen producing tumor (state type)
    3. Non hormone producing tumor (state type)
  2. Coagulopathy (state type)
  3. Endocrine
    1. Hyperthyroidism
    2. Hypothyroidism
    3. Pituitary dysfunction
    4. Hyperprolactinemia (state cause)
    5. Adrenal dysfunction
    6. Hepatic dysfunction hyperestrogenism)
  4. Iatrogenic
    1. Intrauterine contraceptive device
    2. Contraceptive pills
    3. Hormone therapy
  5. Self medication (state drug) 

  1. Munro MG, Critchley H, Broder MS, Fraser IS, for the FIGO Working Group on Menstrual Disorders. FIGO classification system (PALM-COEIN) for causes of abnormal uterine bleeding in nongravid women of reproductive age. Int J Gynecol Obstet 2011;113(1):3–13.
  2. Woolcock  JG,  Critchley  HO,  Munro  MG,  Broder  MS,  Fraser  IS.  Review  of  the confusion in current and historical terminology and de fi nitions for disturbances of menstrual bleeding. Fertil Steril 2008;90(6):2269–80.
  3. Fraser  IS,  Critchley  HO,  Munro  MG.  Abnormal  uterine  bleeding:  getting  our terminology straight. Curr Opin Obstet Gynecol 2007;19(6):591–5.

Parulekar SV. Critical Evaluation of PALM-Coein Classification. JPGO 2016. Volume 3 Number 1. Available from: