Trophoblast

Protocol applies to all gestational trophoblastic malignancies.

Procedures

• Dilatation and Curettage

• Resection

This protocol is intended to assist pathologists in providing clinically useful and relevant information as a result of the examination of surgical specimens. Use of this protocol is intended to be entirely voluntary. If equally valid protocols or similar documents are applicable, the pathologist is, of course, free to follow those authorities. Indeed, the ultimate judgment regarding the propriety of any specific procedure must be made by the physician in light of the individual circumstances presented by a specific patient or specimen.

 

It should be understood that adherence to this protocol will not guarantee a successful result. Nevertheless, pathologists are urged to familiarize themselves with the document. Where a physician chooses to deviate from the protocol based on the circumstances of a particular patient or specimen, the physician is advised to make a contemporaneous written notation of the reason for the procedure followed.

 

The College recognizes that this document may be used by hospitals, attorneys, managed care organizations, insurance carriers, and other payers. However, the document was developed solely as a tool to assist pathologists in the diagnostic process by providing information that reflects the state of relevant medical knowledge at the time the protocol was first published. It was not developed for credentialing, litigation, or reimbursement purposes. The College cautions that any uses of the protocol for these purposes involve considerations that are beyond the scope of this document.

 

I. Dilatation and Curettage           back     Top     Main Page

      A.  CLINICAL INFORMATION

            1.   Patient identification

                  a.   Name

                  b.   Identification number

                  c.   Age (birth date)

            2.   Responsible physician(s)

            3.   Date of procedure

            4.   Other clinical information

                  a.   Relevant history  (Note A)

                        (1)  menstrual history

                        (2)  week of pregnancy

                        (3)  passage of tissue

                        (4)  history of hydatidiform mole

                  b.   Relevant findings (e.g. size of uterus,  ultrasound, hCG level)

                  c.   Clinical diagnosis

                  d.   Procedure (e.g. endometrial biopsy, D&C, spontaneous passage of tissue)

                  e.   Anatomic site(s) of specimen(s) (e.g. uterine corpus, cervix)

 

      B.   MACROSCOPIC EXAMINATION

            1.   Specimen

                  a.   Unfixed/fixed (specify fixative)

                  b.   Size (aggregate dimensions if multiple, after separating tissue from blood)

                  c.   Lesion/tumor

                        (1)  dimensions

                        (2)  descriptive features

                        (3)  vesicles with size of largest

                        (4)  fetal tissue and anomaly

                        (5)  firmness

                        (6)  necrosis

d.   Results of intraprocedural consultation

            2.   Tissue submitted for microscopic evaluation

                  a.   Villous tissue

                        (1)  representative samples, if abundant

                        (2)  All, if sparse

                  b.   Fetal tissue

                  c.   Uterine tissue

            3.   Special studies (specify) (e.g. immuno-histochemistry, DNA analysis [specify type], oncogene analysis, karyotype analysis)

 

      C.  MICROSCOPIC EVALUATION

            1.   Adequacy of specimen (if inadequate for evaluation, specify reason)

            2.   Lesion/tumor

                  a.   Histologic type (Note B)

                  b.   Presence in sharp curettage specimen

                  c.   Presence in suction curettage specimen 

            3.   Additional tissues or pathologic findings, if present

                  a.   Implantation site

                  b.   Endometrium

                  c.   Myometrium

                  d.   Cervix

                  e.   Fetal tissues (cord, amnion, chorion, yolk sac)

                  f.    Fetal anomalies, if present

            4.   Results/status of special studies

            5.   Comments

a.   Correlation with intraprocedural consultation, as appropriate

b.   Correlation with other specimens, as appropriate

c.   Correlation with clinical information, including hCG level, as appropriate           

 

II. Resection             back     Top     Main Page

A.  CLINICAL INFORMATION

            1.   Patient identification

                  a.   Name

                  b.   Identification number

                  c.   Age (birth date)

            2.   Responsible physician(s)

            3.   Date of procedure

            4.   Other clinical information

                  a.   Relevant history  (Note A)

                        (1)  menstrual history

                        (2)  week of pregnancy

                        (3)  passage of tissue

                        (4)  history of hydatidiform mole

                  b.   Relevant findings (e.g. size of uterus, ultrasound, hCG level)

                  c.   Clinical diagnosis

                  d.   Procedure (e.g. abdominal hysterectomy, radical hysterectomy with bilateral salpingo-oophorectomy, staging laparotomy, pelvic exenteration)

                  e.   Anatomic site(s) of specimen(s) (e.g. uterine corpus, cervix)

                 

      B.   MACROSCOPIC EXAMINATION

            1.   Specimen

                  a.   Organ(s)/tissue(s) included

                  b.   Unfixed/fixed (specify fixative)

                  c.   Number of pieces

                  d.   Dimensions

                  e.   Orientation (if indicated by surgeon)

                  f.    Areas indicated by surgeon for specific microscopic evaluation

                  g.   Results of intraoperative consultation

            2.   Lesion/tumor

                  a.   Location (e.g. corpus/fundus/cornu/isthmus/cervix)

                  b.   Size (three dimensions)

                  c.   Descriptive characteristics (e.g. villous tissue/exophytic/color)

                  d.   Extent of invasion (Note C)

                        (1)  into myometrium/serosa/parametrium/cervix

                        (2)  to other organ(s)/tissue(s)

                  e.   Distance from margins

            3.   Additional pathologic findings, if present

                  a.   Evidence of prior sampling or treatment at apparent site of lesion

            4.   Uterine corpus

                  b.   Dimensions

                  c.   Descriptive features of endometrium, myometrium and serosa

                  d.   Lesion/tumor

                        (1)  descriptive features including size, location and extent

                        (2)  relation to main lesion/tumor

                  e.   Resection margins if, appropriate

                  f.    Additional findings, if present

            5.   Uterine cervix

                  a.   Descriptive features including appearance of ectocervix and endocervix

                  b.   Lesion/tumor

                        (1)  descriptive features, including size/location/extent

                        (2)  relation to main lesion/tumor

                  c.   Resection margins, if appropriate

                  d.   Additional findings, if present

            6.   Vagina

                  a.   Size (length, circumference, thickness)

                  b.   Descriptive features (inner and outer surfaces; wall)

                  c.   Lesion/tumor

                  d.   Descriptive features (size/location/ relation to main lesion/tumor)

                  e.   Resection margins, if appropriate

                  f.    Additional findings, if present

            7.   Fallopian tube(s)

                  a.   Dimensions

                  b.   Descriptive features, including dimensions

                  c.   Lesion/tumor

                        (1)  descriptive features (size/location/extent)

                        (2)  relation to main lesion/tumor

                  d.   Resection margins if appropriate

                  e.   Additional findings

            8.   Ovary(ies)

                  a.   Descriptive features, including measurements, outer surface, sectioned surface

                  b.   Lesion/tumor

                        (1)  descriptive features (size/location/extent)

                        (2)  relation to main lesion/tumor

                  c.   Resection margins if appropriate

                  d.   Additional findings (e.g. multiple luteinized follicle cysts)

            9.   Organ in which lesion/tumor primary (uninvolved component)

                  a.   Dimensions

                  b.   Descriptive features

                  c.   Resection margins if appropriate

                  d.   Additional findings, if present

            10. Regional lymph nodes

                  a.   Lesion/tumor

                        (1)  size

                        (2)  descriptive features

                  b.   Additional findings, if present

            11. Other organ(s) or tissue(s) removed (e.g. omentum, staging biopsy specimens)

                  a.   Type(s) or site(s)

                  b.   Dimensions and other descriptive features

                  c.   Lesion/tumor

                        (1)  descriptive features (size/location/extent)

                        (2)  relation to main lesion/tumor

                  d.   Resection margins if appropriate

            12. Tissues submitted for microscopic evaluation

                  a.   Primary lesion/tumor of uterus or other organ - adequate number to demonstrate:

                        (1)  deepest myometrial invasion or extent of involvement

                        (2)  distance from serosa or resection margin

                        (3)  cornual/isthmic/cervical/parametrial involvement, if present

                  b.   Other lesions

                  c.   Grossly uninvolved tissue, as appropriate

                  d.   Staging and lymph node specimens - at least one section of each

                  e.   Omentum - multiple sections whether or not grossly involved

                  f.    Vaginal cuff

                  g.   Frozen section tissue fragment(s) (unless saved for special studies)

                  h.   Other organs/tissues - as appropriate for gross/clinical indications

            13. Special studies (e.g. DNA flow cytometry, genetic studies such as karyotype analysis, image analysis, DNA polymorphism analysis, etc).

 

C.  MICROSCOPIC EVALUATION

            1.   Organ primarily involved

                  a.   Lesion/tumor

                        (1)  histologic type (Note B)

                        (2)  site

                        (3)  extent of invasion (Note C)

                        (4)  depth of invasion from endometrial-junction/thickness of myometrium; or extent of   primary tumor in other organs

                        (5)  closest distance to serosa

                        (6)  blood/lymphatic vessel invasion

                  b.   Resection margins

                  c.   Status of inked areas or areas designated by surgeon

            2.   Additional pathologic findings, if present

                  a.   Implantation site, if present: endometrium, myometrium, cervix

                  b.   Fetal tissues (chorion/amnion/yolk sac)

                  c.   Fetal anomalies, if present

            3.   Regional lymph nodes

                  a.   Total number

                  b.   Number involved by tumor

                  c.   Other findings (e.g. decidua)

            4.   Other organ(s) and tissue(s)

                  a.   Lesion/tumor

                        (1)  Location

                        (2)  Extent

                        (3)  Relation to primary lesion/tumor

                  b.   Resection margins, if appropriate

                  c.   Additional findings (e.g. decidua/hyperreactio luteinalis of ovaries)

            5.   Results/status of special studies (specify)

            6.   Comments

                  a.   Correlation with intraoperative consultation, as appropriate

                  b.   Correlation with other specimens, as appropriate

                  c.   Correlation with clinical information, as appropriate      

 

EXPLANATORY NOTES

 

A. Previous History               back     Top     Main Page

Previous slides should be reviewed by the pathologist if it is deemed necessary by the gynecologist or pathologist for optimal evaluation of the specimen.

B.   Histologic Type                back     Top     Main Page

Histologic Classification of Gestational Trophoblastic Lesions (World Health Organization Classification of Gestational Trophoblastic Lesions).

•     Hydatidiform mole

      -     Complete*

      -     Partial**

•     Invasive hydatidiform mole

•     Choriocarcinoma

•     Placental site trophoblastic tumor***

•     Trophoblastic lesions, miscellaneous

      -     Exaggerated placental site

      -     Placental site nodule and plaque****

•     Unclassified trophoblastic lesions

 

* Usually diploid, 46 chromosomes; no fetal tissues unless with a twin gestation; villi markedly enlarged, hydropic, central cistern; prominent trophoblastic hyperplasia.

 

** Usually triploid, 69 chromosomes; fetal tissues present; villi scalloped, have stromal trophoblastic inclusions; focal trophoblastic hyperplasia, usually of syncytiotrophoblast.

 

*** Malignant tumor of intermediate trophoblast.

 

**** Retention of a nodule or plaque of benign intermediate trophoblast.

 

C.  Staging          back     Top     Main Page

The TNM staging system of the American Joint Committee on Cancer (AJCC) and the International Union Against Cancer (UICC)(2) and the corresponding staging system of the International Federation of Gynecology and Obstetrics (FIGO) are recommended and shown below. They are both based not only on the anatomic extent of the tumor, but on additional factors, including clinical and laboratory findings.

 

FIGO Staging for Gestational Trophoblastic

Tumors (GTTs) (1991)

Stage I                         Disease confined to the uterus

IA                                Disease confined to the uterus with no risk factors

IB                                Disease confined to the uterus with one risk factor

IC                                Disease confined to the uterus with two risk factors

Stage II                        GTT extends outside of the uterus but is limited to the genital structures (adnexa, vagina, broad ligament)

IIA                               GTT involving genital structures without risk factors

IIB                               GTT extends outside of the uterus but limited to genital structures with one risk factor

IIC                               GTT extends outside of the uterus but limited to the genital structures with two risk factors

Stage III                       GTT extends to the lungs with or without known genital tract involvement

IIIA                              GTT extends to the lungs with or without genital tract involvement and with no risk factors

IIIB                              GTT extends to the lungs with or without genital tract involvement and with one risk factor

IIIC                              GTT extends to the lungs with or without genital tract involvement and has two risk factors

Stage IV                       All other metastatic sites

IVA                             All other metastatic sites without risk factors

IVB                              All other metastatic sites with one risk factor

IVC                             All other metastatic sites with two risk factors

 

Risk factors affecting staging include the following:

1.         HCG > 100,000 mIU/ml

2.         Duration of disease > 6 months from termination of the antecedent pregnancy

 

AJCC/UICC TNM Staging for Trophoblastic Tumors

Primary Tumor (T)*

TX                   Primary tumor cannot be assessed

T0                    No evidence of primary tumor

T1                    Tumor confined to uterus

T2                    Tumor extends to other genital structures: vagina, ovary, broad ligament, fallopian tube by metastasis or direct extension

 

*By AJCC/UICC convention, the designation “T” refers to a primary tumor that has not been previously treated. The symbol “p” refers to the pathologic classification of the TNM, as opposed to the clinical classification and is based on gross and microscopic examination.  pT entails a resection of the primary tumor or biopsy adequate to evaluate the highest pT category; pN entails removal of nodes adequate to validate lymph node metastasis; and pM implies microscopic examination of distant lesions.  Clinical classification (cTNM) is usually carried out by the referring physician before treatment during initial evaluation of the patient or when pathologic classification is not possible.

 

Tumor Remaining in the Patient

Tumor remaining in a patient after therapy with curative intent (e.g., surgical resection for cure) is categorized by a system known as R classification, shown below. 

 

RX                   Presence of residual tumor cannot be assessed

R0                    No residual tumor

R1                    Microscopic residual tumor

R2                    Macroscopic residual tumor.

 

For the surgeon, the R classification may be useful to indicate the known or assumed status of the completeness of a surgical excision.  For the pathologist, the R classification is relevant to the status of the margins of a surgical resection specimen.  That is, tumor involving the resection margin on pathologic examination may be assumed to correspond to residual tumor in the patient and may be classified as macroscopic or microscopic according to the findings at the specimen margin(s).

 

Tumor Remaining in a Specimen

In contrast, tumor remaining in a resection specimen from a patient who has undergone previous (neoadjuvant) treatment of any type (radiation therapy alone, chemotherapy therapy alone, or any combined modality treatment) is codified by the TNM using a prescript “y” (e.g., ypT1).  Thus, yTNM indicates the post-treatment status of the tumor.  For many neoadjuvant therapies, the classification of residual disease may be a strong predictor of postoperative outcome.  In addition, the ypTNM classification provides a standardized framework for the collection of data needed to accurately evaluate new neoadjuvant therapies.

 

Locally Recurrent Tumor

In contrast to “residual” tumor, classification of a tumor as “recurrent” requires a documented disease-free interval after definitive therapy.  Recurrent tumor may also be classified according to the TNM categories, but the prefix “r” (e.g., rpT1) is used to indicate the recurrent status of the tumor. 

 

Distant Metastasis (M)

MX                  Distant metastasis cannot be assessed

M0                   No distant metastasis

M1                   Distant metastasis

                        M1a     Metastasis to lung(s)*

                        M1b     Other distant metastasis (e.g. brain) with or without lung metastasis*

* Genital metastasis (vagina, broad ligament, ovary, fallopian tube) is classified as T2.

 

TNM Stage Groupings

Stage   T          M        Risk Factors

IA        T1        M0       without

IB        T1        M0       one

IC        T1        M0       two

IIA       T2        M0       without

IIB       T2        M0       one

IIC       T2        M0       two

IIIA      Any T   M1a     without

IIIB      Any T   M1a     one

IIIC      Any T   M1a     two

IVA     Any T   M1b     without

IVB      Any T   M1b     one

IVC     Any T   M1b     two

 

The following factors should be considered and noted in reporting:

1.         Prior chemotherapy for known GTT.

2.         Placental site tumors should be reported separately.

3.         Histological verification of disease is not required.

REFERENCES                        back     Top     Main Page

1.     Scully RE, Bonfiglio TA, Kurman RJ, Silverberg SG, Wilkinson EJ. World Health Organization International Histological Classification of Tumours. Histological Typing of Female Genital Tract Tumours. New York: Springer-Verlag; 1994.

2.     Fleming ID, Cooper JS, Henson DE, et al. eds. AJCC Manual for Staging of Cancer. 5th ed. Philadelphia, PA: Lippincott Raven; 1997.

 

BIBLIOGRAPHY

•      Bagshawe KD, Lawler SD, Paradinas FJ, Dent J, Brown P, Boxer GM. Gestational trophoblastic tumours following initial diagnosis of partial hydatidiform mole. Lancet. 1990;335:1074-1076.

•      Collins RJ, Ngan HYS, Wong LC. Placental site trophoblastic tumor: With features between an exaggerated placental site reaction and a placental site trophoblastic tumor. Int J Gynecol Pathol. 1990;9:170-177.

•      Conran RM, Hitchcock EI, Popek EJ, et al. Diagnostic considerations in molar gestations. Hum Pathol. 1993;24:41-48.

•      Fukunaga M, Ushigome S, Fukunaga M, Sugishita M. Application of flow cytometry in diagnosis of hydatidiform moles. Mod Pathol. 1993;6:353-359.

•      Fukunaga M, Ushigome S. Malignant trophoblastic tumors: Immunohistochemical and flow cytometric comparison of choriocarcinoma and placental site trophoblastic tumors. Hum Pathol. 1993;24:1098-1106.

•      Howat AJ, Beck S, Fox H, et al. Can histopathologists reliably diagnose molar pregnancy? J Clin Pathol. 1993; 46:599-602.

•      Huettner PC, Gersell DJ. Placental site nodule: A clinicopathologic study of 38 cases. Int J Gynecol Pathol. 1994; 13:191-198.

•      Kurman RJ, Young RH, Main CA, et al. Immunohistochemical localization of placental lactogen and chorionic gonadotropin in the normal placenta and trophoblastic tumors with emphasis on intermediate trophoblast and the placental-site trophoblastic tumor. Int J Gynecol Pathol. 1984;3:101-121.

•      Lage JM, Mark SD, Roberts DJ, et al. A flow cytometric study of 137 fresh hydropic placentas: Correlation between types of hydatidiform moles and nuclear DNA ploidy. Obstet Gynecol. 1992;79:403-410.

•      Lawler SD, Fisher RA, Dent J. A prospective genetic study of complete and partial hydatidiform moles. Am J Obstet Gynecol. 1991;164;1270-1277.

•      Miller D, Jackson R, Ehlen T, McMurtie E. Case report: Complete hydatidiform mole coexistent with a twin live fetus: Clinical course of four cases with complete cytogenetic analysis. Gynecol Oncol. 1993;50:119-123.

•      Silva E, Tornos C, Lage J, Ordonez M, Kavanagh J. Multiple nodules of intermediate trophoblast, an unusual complication of hydatidiform motes. Int J Obstet Gynecol. 1993; 12:324-332.

•      Silverberg SG, Kurman RJ. Atlas of Tumor Pathology. Tumors of the Uterine Corpus and Gestational Trophoblastic Disease. Third Series. Fascicle 3. Washington, DC: Armed Forces Institute of Pathology; 1992.

•      Soper JT, Hammond CB, Lecois JL Jr. Gestational trophoblastic disease. In: Hoskins WJ, Perez CA, Young RC, eds. Principles and Practice of Gynecologic Oncology. Philadelphia, PA: J.B. Lippincott; 1992: 695-714.

•      Stellar MA, Genest DR, Bernstein MR, Lage JM, Goldstein DP, Berkowitz RS. Natural history of twin pregnancy with complete hydatidiform mole and coexisting fetus. Obstet Gynecol. 1994;83:35-42.

•      Szulman AE, Surti U. The syndromes of hydatidiform mole. I. Cytogenetic and morphologic correlations. Am J Obstet Gynecol. 1978;131;665-671.

•      Szulman AE, Surti U. The syndromes of hydatidiform mole. II. Morphologic evolution of the complete and partial mole. Am J Obstet Gynecol. 1978;32:20-27.

•      Young RH, Kurman RJ, Scully RE. Placental site nodules and plaques: A clinicopathologic analysis of 20 cases. Am J Surg Pathol. 1990;4:1001-1009.

Author:

Janice M. Lage, MD

 

©2000. College of American Pathologists (CAP). All rights reserved. None of the contents of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means (electronic, mechanical, photocopying, recording, or otherwise) without prior written permission of the publisher.

 

        Expires as CAP policy in May 2001. A year prior, the protocol will be reviewed and
updated.

 

        Contributors:                            back     Top     Main Page

        CAP Cancer Committee; Donald E. Henson, MD; Enrique Hernandez, MD; Maureen Killacky, MD; Beverly B. Kramer, MD; Rachelle Lanciano, MD; Stanley J. Robboy, MD; Steven G. Ruby, MD; Robert E. Scully, MD; Steven G. Silverberg, MD; Richard Zaino, MD