Molar pregnancy in postmenopausal women: a rare phenomenon

Abstract

Benign gestational trophoblastic disease generally occurs in women of the reproductive age group and is extremely rare in postmenopausal women. We describe a case of complete hydatidform mole in a 60-year-old postmenopausal woman who was referred with diagnosis of suspected malignancy/myoma resulting in delay in management. This case highlights the fact that gestational trophoblastic disease can occur in menopausal woman and this should be included in the differential diagnosis of perimenopausal and postmenopausal haemorrhage to prevent delay in diagnosis and treatment.

Background

Gestational trophoblastic tumours (GTN) are primarily diseases of women of reproductive age and although advanced maternal age is an important risk factor these tumours are exceedingly rare in postmenopausal women.

Case presentation

The 60-year-old, G₅P₄₊₀, 2 years 6 months menopausal woman presented with swelling in the abdomen for last 5 months, bleeding per vaginum and pain in the abdomen for last 1 month.

She had four children and her last pregnancy was 14 years back. Before being referred to our hospital, she was consulting some doctor at her village who, considering her age, menopausal status, lump in abdomen and bleeding per vaginum suspected her (clinically) to be a case of myoma or uterine malignancy. No ultrasonography (USG) was done before she came to our centre. On per abdominal examination a lump of 24 weeks size gravid uterus was present. On per vaginum examination os was closed and uterus was enlarged to a size of 24 weeks pregnancy. No other abnormalities were palpated.

Investigations

Haemoglobin was 7 g% and the pelvic USG showed  typical snow storm appearance which was suggestive of hydatidiform mole. The serum human chorionic gonadotropin (HCG) was 262 100 mIU/ml.

Differential diagnosis

Pregnancy and pregnancy-related problems are rare in older women especially those who are postmenopausal. A postmenopausal women presenting with lump in abdomen, and bleeding per vaginum usually raises suspicion of endometrial malignancy, leiyomyosarcoma, oestrogen-secreting ovarian tumour. Occasionally, myoma or adenomyosis can occur in postmenopausal woman. Very rarely gestational trophoblastic disease can occur in postmenopausal woman presenting with similar symptoms.

Treatment

USG picture along with β-HCG report suggested the diagnosis of molar pregnancy. After arranging one unit of blood, the patient was immediately taken up for suction evacuation. Blood loss at suction was approximately 500 cc. Microscopic examination of the tissue revealed generalised hydropic villi with cisterns and trophoblast proliferation consistent with a complete hydatidform mole. In view of the age of the patient, postmenopausal status and β-HCG >100 000, patient was subsequently taken up for total abdominal hysterectomy and bilateral salpingo-oophroectomy. Histopathology of hysterectomy specimen showed no residual disease in the uterus. Endometrial thickening was present and decidual reaction was present in the endometrium.

Follow-up showed a steady downward trend in the level, which was undetectable within 2 months.

Outcome and follow-up

The patient had an uneventful postoperative period with a negative work up for metastasis which included x-ray of chest, abdominal and pelvic ultrasound. After normalisation of her HCG (after 8 weeks), she was closely followed for a year with monthly serum HCG measurement and thereafter she was lost to follow-up. No reoccurrence was observed during the follow-up period.

Discussion

Pregnancy is uncommon in women over 50 years of age, and when it occurs the outcome is frequently abnormal¹. Pregnancy in older age may either end in spontaneous abortion or may result in molar pregnancy.

A review of the literature showed that occurrence of gestational trophoblastic disease (GTD) in postmenopausal women is rare.^2–4 GTD in the perimenopausal and postmenopausal age group may be benign or malignant but in the postmenopausal age group is usually malignant.^{5 6} Tsukamoto et al ⁷ reported 20 cases of trophoblastic disease in women aged 50 or older. In total, 25% patients were diagnosed with a choriocarcinoma, 35% were diagnosed with a hydatidform mole and 40% were diagnosed with an invasive mole. However, none of the patients with hydatidform mole were postmenopausal. In another larger series, Jequier and Winterton⁶ reviewed 109 cases of GTD in women older than 50 years. They found malignant disease in 28.4%, benign moles in 47.7% and unclear pathological diagnosis in the remaining 23.9%. There were only two postmenopausal patients who had a documented period of an amenorrhoea greater than 1 year and were diagnosed with a benign mole. To our knowledge, our case represents the sixth case in world literature ^{2 6 8–10} of a complete hydatidform mole in a postmenopausal woman with a history of more than 2 years of amenorrhoea (table 1).

Table 1.

Five published cases of hydatidform mole in postmenopausal woman

Serial number	Authors	Reporting year	Cases	Age (years)	Treatment	Reoccurrence
1	Jequier and Winterton6	1973	2	50 54	Hysterectomy dilatation and curettage	None
2	Roy et al10	2000	1	61	Hysterectomy	None
3	Garica et al2	2004	1	55	Hysterectomy	None
4	Abike et al8	2008	1	56	Hysterectomy	None
5	Malik et al9	2009	1	52	Hysterectomy	None

Identification of GTD in women over 50 years of age is difficult as menopause is expected and the possibility of pregnancy is often overlooked or denied.¹¹ In our case, the patient being postmenopausal, the diagnosis of myoma or malignancy was made initially and the possibility of molar pregnancy was not considered resulting in delay in management of the patient. Owing to the high rate (56.3%) of malignant sequelae after molar evacuation, a primary hysterectomy for the treatment of hydatidiform mole in this age group is recommended.¹² However, there remains an 8–20% risk of postmolar GTD in elderly patients after hysterectomy and close follow-up with serum β-HCG is indicated.¹¹

The patient was amenorrhic for more than 2 years. According to the North American menopause society, menopause is clinically defined as the period that begins after the final episode of menstrual bleeding. The aging ovaries continue to produce certain amounts of oestrogen and androgens for at least 10 years after the start of menopause.¹³ At the time of menopause the number of follicles in the ovaries decrease, oestrogen production continues to fall. When a level incompatible with the induction of luteinising hormone (LH) surge is reached, ovulation may cease or frequently may become irregular. Clinically, this is associated with irregular cycles and a shortened luteal phase, or anovulatory cycles with unopposed oestrogen stimulation and endometrial hyperplasia. Anovulatory cycles may be interspersed with ovulatory cycles. A period of amenorrhoea with elevated follicle stimulating hormone and LH may mimic menopause but is followed a few months later by an ovulatory cycle and normal gonadotrophin level.¹⁴ This transitional period of progressive loss of ovarian function and sporadic ovulatory cycles explains the occurrence of molar pregnancy in a 60-year-old woman.

In conclusion, even though gestational trophoblastic disease is rare, it can occur in postmenopausal women. Therefore, a high level of suspicion should be maintained and GTD should be included in the differential diagnosis of perimenopausal bleeding to prevent delay in diagnosis and treatment.

Learning points.

• Although rare, gestational trophoblastic disease should be considered in evaluation of perimenopausal and postmenopausal vaginal bleeding.

• In menopausal women, since risk of subsequent development of choriocarcinoma is high, definitive treatment with total abdominal hysterectomy should be considered.

• Long-term follow-up with β-human chorionic gonadotropin should be carried out to detect recurrence.