Author Information
Gwendolyn Fernandes*, Asmita Patil**, PY Samant*** SV
Parulekar****
(* Associate Professor, Department of Pathology, ** Senior
Resident, *** Additional Professor **** Professor and Head, Department of Obstetrics
& Gynecology, Seth GS Medical College & KEM Hospital, Parel, Mumbai,
India.)
Abstract
Osseous metaplasia of the endometrium is a rare condition
characterized by the presence of mature or immature bone in the endometrium.
Most cases present with secondary infertility following an abortion or chronic
endometritis, some patients are asymptomatic, while others have menstrual
irregularities or menorrhagia. We present two cases of osseous metaplasia of
the endometrium.
Introduction
Osseous metaplasia of the endometrium is a rare condition
characterized by the presence of mature or immature bone in the endometrium.
Most cases present with secondary infertility following an abortion or chronic
endometritis, some patients are asymptomatic, while others have menstrual
irregularities or menorrhagia. Ultrasound examination showing characteristic
hyperechogenic pattern of osseous tissue within the uterus helps suspect the
diagnosis. The final diagnosis is confirmed by hysteroscopy and removal of the
bony tissue by curettage. Complete removal of the bony spicules from the
endometrial cavity by hysteroscopy under ultrasonic guidance usually cures the
patient.
Case Report 1
A 24 year old woman presented with secondary infertility for
8 years. She had had a spontaneous abortion at 4 months of amenorrhea 8 years
ago, at which time she had undergone a blunt curettage. Since then she had had
menorrhagia, the bleeding lasting for 8 to 10 days every 30 days. Her general
and systemic examination revealed no abnormality. Her uterus was of 6 weeks'
size, smooth and firm. There was no pelvic tenderness or mass. Her hemogram,
blood sugars, liver and renal function tests, HIV, VDRL and her husband's semen
analysis reports were within normal limits. Difficulty was encountered during
passage of a uterine sound and bony spicules were seen in the endometrium
during hysteroscopy. All the bony spicules were removed by a sharp curette
under laparoscopic control to prevent uterine perforation. She made an
uneventful recovery. Her menorrhagia was cured. Three months later she was lost
to follow up, and her fertility status remains unknown.
Figure
1 – Microphotograph showing mature bone surrounded by blood clot, fibrinous
material and inflammatory cells.
Figure
2 – Microphotograph showing higher magnification of the bony tissue.
Figure
3 – Microphotograph showing well-formed mature bone, calcific material and
inflammatory cells.
Case Report 2
A 35 year old para 4 MTP 1 presented with abnormal uterine
bleeding (irregular menses with soakage of 2 pads per day) for 4 years. She had
had 4 normal deliveries followed by a medical termination of pregnancy at 3
months of amenorrhea 4 years ago. Her general and systemic examination revealed
no abnormality. Her uterus was of normal size, smooth and firm. There was no
pelvic tenderness or mass. Her hemogram, blood sugars, liver and renal function
tests, chest radiograph and electrocardiogram were normal. Endometrial
aspiration showed no malignant cells. Her ultrasonography showed a 2.9 cm sized
calcified lesion, which was interpreted as either endometrial calcification or
calcified submucosal leiomyoma. During dilatation and curettage, there was
difficulty in passage of a uterine sound. Presence of bony spicules in the
endometrium was suspected. These spicules were removed held by a long, curved,
hemostat, followed by curettage. She made an uneventful recovery. Her
menorrhagia was cured without any additional treatment.
Figure
4 - Microphotograph showing calcified
bone and inflammatory cells.
Figure
5 – Microphotograph showing abundant calcific material and mature bone.
Figure
6 – Microphotograph showing higher power view of the mature bone.
Discussion
Osseous metaplasia of the endometrium is a rare condition
characterized by the presence of mature or immature bone in the endometrium.[1]
Its estimated incidence is 3/10000, there being about eighty cases described in
the literature.[2] It has been referred to by various names ectopic
intrauterine bone, heterotopic intrauterine bone, endometrial ossification etc.[3]
Clinically the patients are in the reproductive age group. A
history of a previous pregnancy or abortion has been reported in more than 80%
cases.[,3,4,5] The interval between the antecedent pregnancy and
detection of endometrial ossification varies from 2 months to 14 years.[6]
In our cases, it was 8 and 4 years respectively. Most cases present with
secondary infertility following an abortion or chronic endometritis, some
patients are asymptomatic, while others have menstrual irregularities or
menorrhagia.[5,7] One of our patients had secondary infertility and
the other had menorrhagia. Ultrasound examination showing characteristic
hyperechogenic pattern of osseous tissue within the uterus helps suspect the
diagnosis. The final diagnosis is confirmed by hysteroscopy and removal of the
bony tissue by curettage.
There have been various controversies regarding the etiology
and pathogenesis of osseous metaplasia of the endometrium. There have been
debates on whether the osseous tissue was of maternal or fetal origin. However
genetic analysis of the osseous tissue, and comparison with the DNA of both the
parents, have shown that there is no male paternal genetic material in it,
ruling out a fetal origin. There have been many theories of its origin, such as
dystrophic calcifications and ossification of post-abortive endometritis,
heterotopia, metaplasia in healing tissue, metastatic calcification, and
prolonged estrogenic therapy after abortion.[3,4,5,8,9] The most accepted theory of the origin of the
osseous tissue is metaplasia of endometrial stromal cells into osteoblastic
cells which produce the bone.[6] Inflammatory conditions like
endometrial tuberculosis, chronic endometritis, and pyometra, trauma of
curettage or instrumentation are causes of chronic inflammatory pathology and
these can result in endometrial osseous metaplasia.[6] In India,
endometrial tuberculosis should be ruled out as a cause of infertility as well
as endometrial calcification and ossification.
It is also important for pathologists to avoid making an
erroneous diagnosis of malignant mullerian tumor on histology.[5,6,7]
This nonneoplastic etiology should not be missed.
Osseous metaplasia is a treatable condition. Complete
removal of the bony spicules from the endometrial cavity by hysteroscopy under
ultrasonic guidance usually cures the patient.[6,10,11]
References
1.
Umashankar T, Patted S, RS
Handigund RS. Endometrial osseous metaplasia: Clinicopathological study of a
case and literature review. J Hum Reprod Sci 2010;3(2): 102–104.
2.
Kishore kumar BN, Dr. Deepak Das
D, Shivaraj HG. Endometrial osseous metaplasia : A case report. Int J Biol Med Res. 2012;3(2):
1865-1866.
3.
Hsu C. Endometrial ossification.
Br J Obstet Gynaecol. 1975;82:836–9.
4.
Dutt S. Endometrial ossification
associated with secondary infertility. Br J Obstet Gynaecol 1978;85:787–9.
5.
Bhatia NN, Hoshiko MG. Uterine
osseous metaplasia. Obstet Gynecol 1982;60:256–9.
6.
Bahçeci M, Demirel LC. Osseous
metaplasia of the endometrium: a rare cause of infertility and its hysteroscopic
management. Hum Reprod 1996;11:2537–9.
7.
Shimizu M, Nakayama M. Endometrial
ossification in a postmenopausal woman. J Clin Pathol 1997;50:171–2.
8.
Acharya U, Pinion SB, Parkin DE
9.
Waxman M, Moussouris HF.
Endometrial ossification following an abortion. Am J Obstet Gynecol
1978;130:587–8.
10.
Coccia ME, Becattini C, Bracco GL,
Scarselli G. Ultrasound-guided hysteroscopic management of endometrial osseous
metaplasia. Ultrasound Obstet Gynecol. 1996;8:134–6.
11.
Lee JY, Lee HA, Kwon HM, Na SH,
Hwang JY, Lee DH. A case of endometrial osseous metaplasia treated by
hysteroscopic operation. Korean J Obstet Gynecol 2012;55(5):361-365.
Citation