Author Information
Singhania N*, Bhandari P**, Gupta AS***.
(* Junior resident, ** Senior resident, *** Professor, Department of Obstetrics & Gynecology, Seth G S Medical College and K E M Hospital, Mumbai, India.)
Abstract
Ovarian dysgerminoma, the commonest malignant tumor of germ cell origin, predominantly affects young women. About 75 % of dysgerminoma’s occur between the age group of 10 - 30 years and thus can affect the fertility or may be associated with pregnancy. We present one such case of dysgerminoma associated with pregnancy.
Introduction
Classification of ovarian tumors is based on their origin. These are of three types; epithelial, germ cell and sex cord tumors. Commonest are the epithelial tumors. Only 30 % of all ovarian neoplasms and 3 % of all ovarian malignancies are germ cell tumors (GCTs). Ovarian germ cell tumors, derived from the primordial germ cells, are further divided into subgroups based on the histological features. Mature teratoma being the commonest benign variety while dysgerminoma is the commonest malignant germ cell tumor.
Case Report
A 27 year old, gravida 3, para 2, living 2 with previous two full term normal deliveries, at 38.3 weeks of gestation was referred from a private hospital to our emergency department in view of fever and abdominal discomfort for the prior two days. On examination, she was conscious, oriented, febrile with a temperature of 1000 F, and pulse was 108/ min.. Her systemic examination was normal. On per abdomen examination uterus was full term, relaxed, and vertex was the presenting part. FHS were 146/ min., On per vaginal examination cervix was undilated, and uneffaced. She was admitted with the physician for fever. On investigation, Hemoglobin was 11 gm%, TLC was 3,000/ mm3, and platelet count was 81,000/ mm3. Dengue IgG and IgM, widal test, leptospirosis IgG & IgM were negative, malarial parasite was not detected on peripheral smear. Serum biochemistry was normal wherein BUN was 9.1 mg/dl, creatinine was 0.7 mg/dl, and electrolytes were normal, SGOT and SGPT were 329 and 39 u/l respectively. Blood sugar and thyroid profile were within normal limits. Next day she went into spontaneous, precipitate labor and delivered vaginally a full term female baby of 2.4 Kg with APGAR score of 6/10 and 7/10 at 1 minute and 5 minutes respectively. Neonate was kept in NICU. There was a 3rd degree prolapse . Cervix was entirely out of the introitus after delivery. After delivery, she was conscious oriented, and all her vital parameters were normal. Around 3-4 hours later she suddenly started complaining of breathlessness. Her extremities were cold, pulse was 128/ min., feeble and her systolic blood pressure was 60 mm of Hg. Chest was clear. Crystalloids and colloids were given to her but still her systolic BP remained 60 mm of Hg. Abdominal kept distending. Physician started her on two inotropes; dopamine and noradrenaline. On re-examination a hard mass of approximately 20x20 cm with irregular surface was felt in the abdomen behind the gravid, well contracted uterus. The lower end of the mass was also felt through the right and posterior fornix . Groove sign was present suggestive of a right adnexal mass. There was no active vaginal bleeding. Her relatives then produced her early antenatal records of a private practitioner wherein an ultrasound (USG) done in 2nd trimester of pregnancy showed detection of a heterogeneous right ovarian mass of 12x8 cm at 22 weeks of gestation. Review of subsequent USG’s was done. None of them commented about this mass. Her biochemical, hematological and serological investigations were repeated. Her hemoglobin was 7.2 mg/dl, total leukocyte count was 9200/mm3, platelet count had dropped to 80,000/ mm3, PT test was 21.8s against a control of 13.0s. INR was 1.81, LDH was 2744 IU/L. Arterial blood gas analysis showed a pH of 7.23, pCO2 11 mm Hg, pO2 148 mm Hg, HCO3 4.6 mEq/L, and lactate levels were 10.7 mmol/L. This was suggestive of metabolic acidosis. An ultrasound that was repeated soon after delivery showed mild ascites and a septate, hyperechoic, heterogeneous mass with solid and multiple cystic components of approximately 26*22*14 cm arising from the right adnexa, extending upto the epigastrium. Ovaries could not be identified separately. She was taken for emergency exploratory laparotomy with the diagnosis of rupture or torsion of an adnexal mass. Introperatively, ascitic fuid of approximately 500 cc was aspirated and 20 cc fluid was collected and sent for cytology. A Large, lobulated, hard, right ovarian mass of approximately 25x20x10 cm was present. No evidence of torsion of mass or breach of capsule was found. Left sided fallopian tubes, left sided ovary and the postpartum uterus appeared normal.[Figure 1] Right ovarian mass was removed after clamping and cutting the pedicle and then pedicle was ligated. On handling of the mass the mass had a tendency of splitting up. [Figure2] Right fallopian tube could not be removed due to high vascularity. There was no evidence of parietal peritoneal, omental and liver metastasis. Frozen section could not be done as facilities were not available during emergency hours. Intraoperatively, iliac and para-aortic lymph nodes were not palpable. Surgical staging was stage 1A. The mass weighed approximately 3.02 kgs.[Figure 3] Even though the capsule of the mass was intact it appeared very fragile and the mass split open on handling. No incision was required to open it. Gross inner surface of the neoplasm showed predominantly solid areas with central and a few peripheral hemorrhagic area (figure 4).
Singhania N*, Bhandari P**, Gupta AS***.
(* Junior resident, ** Senior resident, *** Professor, Department of Obstetrics & Gynecology, Seth G S Medical College and K E M Hospital, Mumbai, India.)
Abstract
Ovarian dysgerminoma, the commonest malignant tumor of germ cell origin, predominantly affects young women. About 75 % of dysgerminoma’s occur between the age group of 10 - 30 years and thus can affect the fertility or may be associated with pregnancy. We present one such case of dysgerminoma associated with pregnancy.
Introduction
Classification of ovarian tumors is based on their origin. These are of three types; epithelial, germ cell and sex cord tumors. Commonest are the epithelial tumors. Only 30 % of all ovarian neoplasms and 3 % of all ovarian malignancies are germ cell tumors (GCTs). Ovarian germ cell tumors, derived from the primordial germ cells, are further divided into subgroups based on the histological features. Mature teratoma being the commonest benign variety while dysgerminoma is the commonest malignant germ cell tumor.
Case Report
A 27 year old, gravida 3, para 2, living 2 with previous two full term normal deliveries, at 38.3 weeks of gestation was referred from a private hospital to our emergency department in view of fever and abdominal discomfort for the prior two days. On examination, she was conscious, oriented, febrile with a temperature of 1000 F, and pulse was 108/ min.. Her systemic examination was normal. On per abdomen examination uterus was full term, relaxed, and vertex was the presenting part. FHS were 146/ min., On per vaginal examination cervix was undilated, and uneffaced. She was admitted with the physician for fever. On investigation, Hemoglobin was 11 gm%, TLC was 3,000/ mm3, and platelet count was 81,000/ mm3. Dengue IgG and IgM, widal test, leptospirosis IgG & IgM were negative, malarial parasite was not detected on peripheral smear. Serum biochemistry was normal wherein BUN was 9.1 mg/dl, creatinine was 0.7 mg/dl, and electrolytes were normal, SGOT and SGPT were 329 and 39 u/l respectively. Blood sugar and thyroid profile were within normal limits. Next day she went into spontaneous, precipitate labor and delivered vaginally a full term female baby of 2.4 Kg with APGAR score of 6/10 and 7/10 at 1 minute and 5 minutes respectively. Neonate was kept in NICU. There was a 3rd degree prolapse . Cervix was entirely out of the introitus after delivery. After delivery, she was conscious oriented, and all her vital parameters were normal. Around 3-4 hours later she suddenly started complaining of breathlessness. Her extremities were cold, pulse was 128/ min., feeble and her systolic blood pressure was 60 mm of Hg. Chest was clear. Crystalloids and colloids were given to her but still her systolic BP remained 60 mm of Hg. Abdominal kept distending. Physician started her on two inotropes; dopamine and noradrenaline. On re-examination a hard mass of approximately 20x20 cm with irregular surface was felt in the abdomen behind the gravid, well contracted uterus. The lower end of the mass was also felt through the right and posterior fornix . Groove sign was present suggestive of a right adnexal mass. There was no active vaginal bleeding. Her relatives then produced her early antenatal records of a private practitioner wherein an ultrasound (USG) done in 2nd trimester of pregnancy showed detection of a heterogeneous right ovarian mass of 12x8 cm at 22 weeks of gestation. Review of subsequent USG’s was done. None of them commented about this mass. Her biochemical, hematological and serological investigations were repeated. Her hemoglobin was 7.2 mg/dl, total leukocyte count was 9200/mm3, platelet count had dropped to 80,000/ mm3, PT test was 21.8s against a control of 13.0s. INR was 1.81, LDH was 2744 IU/L. Arterial blood gas analysis showed a pH of 7.23, pCO2 11 mm Hg, pO2 148 mm Hg, HCO3 4.6 mEq/L, and lactate levels were 10.7 mmol/L. This was suggestive of metabolic acidosis. An ultrasound that was repeated soon after delivery showed mild ascites and a septate, hyperechoic, heterogeneous mass with solid and multiple cystic components of approximately 26*22*14 cm arising from the right adnexa, extending upto the epigastrium. Ovaries could not be identified separately. She was taken for emergency exploratory laparotomy with the diagnosis of rupture or torsion of an adnexal mass. Introperatively, ascitic fuid of approximately 500 cc was aspirated and 20 cc fluid was collected and sent for cytology. A Large, lobulated, hard, right ovarian mass of approximately 25x20x10 cm was present. No evidence of torsion of mass or breach of capsule was found. Left sided fallopian tubes, left sided ovary and the postpartum uterus appeared normal.[Figure 1] Right ovarian mass was removed after clamping and cutting the pedicle and then pedicle was ligated. On handling of the mass the mass had a tendency of splitting up. [Figure2] Right fallopian tube could not be removed due to high vascularity. There was no evidence of parietal peritoneal, omental and liver metastasis. Frozen section could not be done as facilities were not available during emergency hours. Intraoperatively, iliac and para-aortic lymph nodes were not palpable. Surgical staging was stage 1A. The mass weighed approximately 3.02 kgs.[Figure 3] Even though the capsule of the mass was intact it appeared very fragile and the mass split open on handling. No incision was required to open it. Gross inner surface of the neoplasm showed predominantly solid areas with central and a few peripheral hemorrhagic area (figure 4).
Figure 1. The postpartum uterus (U) and the mass (M).
Figure 2. Mass splitting up on handling
Figure 3. Gross external appearance of the tumor.
Figure 4. Gross internal appearance of the tumor with arrow pointing towards hemorrhagic areas.
Intraoperatively, she received two units of whole blood and 4 units of fresh frozen plasma (FFP). Postoperatively, she was shifted to ICCU. She was in ICCU for 5 days. She was on the ventilator and on 2 inotropes for 3 days. Ionotropes were gradually tapered off. She was totally transfused with 2 units whole blood, 4 units of packed red blood cells, 10 units of FFP, 6 units of platelets, and 10 units of cryoprecipitate. She was weened off the ventilator after 3 days. Histopathological examination was suggestive of nested pattern with thin fibrovascular septa, large tumor cells with pleomorphic nuclei, with many mitotic figures and large areas of necrosis. The fibrovascular septae showed presence of lymphocytes. No other germ cell component was seen. The features were consistent with dysgerminoma of the ovary. Ascitic fluid cytology was negative for malignant cells. She was stable, sutures were removed after 12 days. She was discharged and referred to a oncology centre where she was advised to follow up with abdominal CECT and tumor markers every 3 month. Baby expired on day 2 of life due to sepsis and lactic acidosis.
Discussion
Ovarian germ cell tumors commonly affects girls in the age group of 15-19 years, and they are also seen in association with pregnancy. The estimated incidence of ovarian tumors is approximately 1 in 1000 pregnancies of which approximately 3–6 % are malignant.[1,2] Etiological factors for it are ill understood, few of them have found to be associated with gonadal dysgenesis and mixed gonadal dysgenesis, however 95% of females are cytogenetically normal.[3] These tumors are usually asymptomatic and are diagnosed as an adnexal mass during routine antenatal ultrasound imaging. In our case the mass was missed in the early 2nd trimester scan by the private practitioner where she registered for antenatal care. These tumors may present with pain, mass or distension of abdomen. In our case it was clinically missed possibly because the mass hid behind the full term gravid uterus and so could not be palpated. Differentiating ovarian malignancies from functional cysts or benign ovarian tumors during pregnancy is a major challenge as standard diagnostic methods could not be applied. Few important markers of germ cell tumors are serum alpha feto protein (AFP), human chorionic gonadotropin (hCG), and lactic dehydrogenase (LDH). Some of these tumor markers are synthesized and secreted physiologically during fetal development like hCG, AFP, inhibin, thus these cannot be used for interpretation in pregnancy.[4] Imaging studies like ultrasound (USG) and MRI are the best tools at present to diagnose adnexal masses during pregnancy and differentiate between benign and malignant ones. Few characteristic ultrasound features of adnexal masses that have been associated with increased risk of malignancy include size, solid components or heterogeneous/complex appearance, excrescences/papillary structures, internal septations, bilaterality, irregular borders, increased vascularity, low resistance blood flow, and presence of ascites.[4] Among these findings our USG was suggestive of heterogeneous mass with septations and ascites, suggesting increased risk of malignancy. Ovarian masses in pregnancy are associated with increased risk of torsion, incarceration, rupture, and or hemorrhage and these can occur in the antepartum, intrapartum during vaginal delivery or in the puerperal period. The chances of torsion was less likely in our case as the tumor was big enough to extend till epigastrium, giving no space for torsion, however sudden hemorrhage could have occured due to trauma during childbirth, as shown in figure 4, which could be one of the possible cause of neurogenic shock and collapse of our patient. The risk of torsion among pregnant patients with adnexal tumors >4 cm increases. According to studies, 51 % of torsion’s occurred in tumors measuring 6–8 cm in diameter. The highest rate of torsion occurred around 15th - 16th week of gestation.[5] The natural course of pregnancy in cases of dysgerminoma is extremely difficult, due to large sizes of the tumors and collection of fluid. There was precipitate labor and 3rd degree prolapse in our case as the tumor size was big, it filled the abdomen along with the gravid uterus thus increasing the intra-abdominal pressure causing precipitate labor and pulsion prolapse. In a study conducted by Karlen JR et al among 27 pregnant women with dysgerminoma, 25% cases had fetal demise.[6] Even in our case baby died on day 2 of life, due to severe sepsis and lactic acidosis, probably due to long term asphyxiation caused by the pressure effect of the mass on the uterus and the sudden precipitate labor. Several authors have stated that surgical intervention is required immediately in situations where malignancy is suspected, during acute complication like torsion or rupture or if there is an increase by 30-50 % in size during pregnancy , regardless of the gestational age.[7,8,9] The ideal time for surgery is 14–22 weeks gestational age as most of the functional cysts disappear by that time, good operative field can be achieved with minimal uterine manipulation and low risk of obstetric complication.[10] The ideal time window was missed in our case, due to improper reviewing of reports and poor clinical acumen. The surgery aims at removal of the mass to avoid complications during pregnancy, to stage or to debulk the tumor if malignancy is identified. In our case the surgery was done with the aim to debulk the tumor and to do surgical staging. Decision for surgery in an unstable patient was difficult. However, had we deferred the surgery in view of her being hemodynamically unstable, the tumor would have broken piece meal spontaneously in the abdomen, as it was very fragile. In all cases frozen section must be done. Quirk and Natarajan have reported that approximately 75 % of women with dysgerminoma present with clinical stage Ia disease.[11] Dysgerminoma confined to capsule of one ovary (stage 1A) is best managed by unilateral salphingoophorectomy.[12] Staging is important, as adjuvant therapy during pregnancy is initiated only in advanced stage disease. Routine biopsy or wedge-resection of the contralateral ovary is not necessary unless it is involved. In cases of advanced stage disease cytoreduction should be undertaken. An interval cytoreduction followed by chemotherapy in second trimester and completion of pregnancy is a reasonable approach.[13] The chemotherapeutic agents are lethal for use in first trimester causing fetal death, growth restriction or teratogenic effects. Malformation risk is 10 % with single drug and 25 % with combination chemotherapy in the first trimester. However Kim and Park in their study have documented the use of chemotherapeutic agents during the second trimester and delivery of a normal infant.[14] Recurrence of dysgerminoma’s is commonly seen in first 2–3 years after treatment. Therefore, follow-up should be scheduled at every 3–4 months for the first 3 years, every 6 months during the fourth and fifth years, and annual surveillance thereafter. CT imaging should be done during 6th and 12th month, especially if tumor markers were negative at the time of diagnosis. Patients should be observed for up to 10 years for rarely occurring late recurrences.[16] The survival rates for dysgerminoma’s presenting at early and advanced stages are 95 and >80 %, respectively. In stage 1a dysgerminoma, after unilateral salpingo-oophorectomy relapse rate ranged from 10 to 20%. Patients who suffer relapses and undergo chemotherapy, the survival rate is greater than 90%.[17]
References
Singhania N, Bhandari P, Gupta AS. Postpartum Collapse In A Case Of Giant Ovarian Dysgerminoma In Pregnancy. JPGO 2019. Vol 6 No. 7. Available from: https://www.jpgo.org/2019/07/postpartum-collapse-in-case-of-giant.html
Intraoperatively, she received two units of whole blood and 4 units of fresh frozen plasma (FFP). Postoperatively, she was shifted to ICCU. She was in ICCU for 5 days. She was on the ventilator and on 2 inotropes for 3 days. Ionotropes were gradually tapered off. She was totally transfused with 2 units whole blood, 4 units of packed red blood cells, 10 units of FFP, 6 units of platelets, and 10 units of cryoprecipitate. She was weened off the ventilator after 3 days. Histopathological examination was suggestive of nested pattern with thin fibrovascular septa, large tumor cells with pleomorphic nuclei, with many mitotic figures and large areas of necrosis. The fibrovascular septae showed presence of lymphocytes. No other germ cell component was seen. The features were consistent with dysgerminoma of the ovary. Ascitic fluid cytology was negative for malignant cells. She was stable, sutures were removed after 12 days. She was discharged and referred to a oncology centre where she was advised to follow up with abdominal CECT and tumor markers every 3 month. Baby expired on day 2 of life due to sepsis and lactic acidosis.
Discussion
Ovarian germ cell tumors commonly affects girls in the age group of 15-19 years, and they are also seen in association with pregnancy. The estimated incidence of ovarian tumors is approximately 1 in 1000 pregnancies of which approximately 3–6 % are malignant.[1,2] Etiological factors for it are ill understood, few of them have found to be associated with gonadal dysgenesis and mixed gonadal dysgenesis, however 95% of females are cytogenetically normal.[3] These tumors are usually asymptomatic and are diagnosed as an adnexal mass during routine antenatal ultrasound imaging. In our case the mass was missed in the early 2nd trimester scan by the private practitioner where she registered for antenatal care. These tumors may present with pain, mass or distension of abdomen. In our case it was clinically missed possibly because the mass hid behind the full term gravid uterus and so could not be palpated. Differentiating ovarian malignancies from functional cysts or benign ovarian tumors during pregnancy is a major challenge as standard diagnostic methods could not be applied. Few important markers of germ cell tumors are serum alpha feto protein (AFP), human chorionic gonadotropin (hCG), and lactic dehydrogenase (LDH). Some of these tumor markers are synthesized and secreted physiologically during fetal development like hCG, AFP, inhibin, thus these cannot be used for interpretation in pregnancy.[4] Imaging studies like ultrasound (USG) and MRI are the best tools at present to diagnose adnexal masses during pregnancy and differentiate between benign and malignant ones. Few characteristic ultrasound features of adnexal masses that have been associated with increased risk of malignancy include size, solid components or heterogeneous/complex appearance, excrescences/papillary structures, internal septations, bilaterality, irregular borders, increased vascularity, low resistance blood flow, and presence of ascites.[4] Among these findings our USG was suggestive of heterogeneous mass with septations and ascites, suggesting increased risk of malignancy. Ovarian masses in pregnancy are associated with increased risk of torsion, incarceration, rupture, and or hemorrhage and these can occur in the antepartum, intrapartum during vaginal delivery or in the puerperal period. The chances of torsion was less likely in our case as the tumor was big enough to extend till epigastrium, giving no space for torsion, however sudden hemorrhage could have occured due to trauma during childbirth, as shown in figure 4, which could be one of the possible cause of neurogenic shock and collapse of our patient. The risk of torsion among pregnant patients with adnexal tumors >4 cm increases. According to studies, 51 % of torsion’s occurred in tumors measuring 6–8 cm in diameter. The highest rate of torsion occurred around 15th - 16th week of gestation.[5] The natural course of pregnancy in cases of dysgerminoma is extremely difficult, due to large sizes of the tumors and collection of fluid. There was precipitate labor and 3rd degree prolapse in our case as the tumor size was big, it filled the abdomen along with the gravid uterus thus increasing the intra-abdominal pressure causing precipitate labor and pulsion prolapse. In a study conducted by Karlen JR et al among 27 pregnant women with dysgerminoma, 25% cases had fetal demise.[6] Even in our case baby died on day 2 of life, due to severe sepsis and lactic acidosis, probably due to long term asphyxiation caused by the pressure effect of the mass on the uterus and the sudden precipitate labor. Several authors have stated that surgical intervention is required immediately in situations where malignancy is suspected, during acute complication like torsion or rupture or if there is an increase by 30-50 % in size during pregnancy , regardless of the gestational age.[7,8,9] The ideal time for surgery is 14–22 weeks gestational age as most of the functional cysts disappear by that time, good operative field can be achieved with minimal uterine manipulation and low risk of obstetric complication.[10] The ideal time window was missed in our case, due to improper reviewing of reports and poor clinical acumen. The surgery aims at removal of the mass to avoid complications during pregnancy, to stage or to debulk the tumor if malignancy is identified. In our case the surgery was done with the aim to debulk the tumor and to do surgical staging. Decision for surgery in an unstable patient was difficult. However, had we deferred the surgery in view of her being hemodynamically unstable, the tumor would have broken piece meal spontaneously in the abdomen, as it was very fragile. In all cases frozen section must be done. Quirk and Natarajan have reported that approximately 75 % of women with dysgerminoma present with clinical stage Ia disease.[11] Dysgerminoma confined to capsule of one ovary (stage 1A) is best managed by unilateral salphingoophorectomy.[12] Staging is important, as adjuvant therapy during pregnancy is initiated only in advanced stage disease. Routine biopsy or wedge-resection of the contralateral ovary is not necessary unless it is involved. In cases of advanced stage disease cytoreduction should be undertaken. An interval cytoreduction followed by chemotherapy in second trimester and completion of pregnancy is a reasonable approach.[13] The chemotherapeutic agents are lethal for use in first trimester causing fetal death, growth restriction or teratogenic effects. Malformation risk is 10 % with single drug and 25 % with combination chemotherapy in the first trimester. However Kim and Park in their study have documented the use of chemotherapeutic agents during the second trimester and delivery of a normal infant.[14] Recurrence of dysgerminoma’s is commonly seen in first 2–3 years after treatment. Therefore, follow-up should be scheduled at every 3–4 months for the first 3 years, every 6 months during the fourth and fifth years, and annual surveillance thereafter. CT imaging should be done during 6th and 12th month, especially if tumor markers were negative at the time of diagnosis. Patients should be observed for up to 10 years for rarely occurring late recurrences.[16] The survival rates for dysgerminoma’s presenting at early and advanced stages are 95 and >80 %, respectively. In stage 1a dysgerminoma, after unilateral salpingo-oophorectomy relapse rate ranged from 10 to 20%. Patients who suffer relapses and undergo chemotherapy, the survival rate is greater than 90%.[17]
References
- Rahman MS, Al-Sibai MH, Rahman J, Al‐Suleiman SA, El‐Yahia AR, Al‐Mulhim AA et al. Ovarian carcinoma associated with pregnancy. A review of 9 cases. Acta Obstetricia et Gynecologica Scandinavica. 2002;81(3):260-264.
- Zhao XY, Huang HF, Lian LJ, Lang JH. Ovarian cancer in pregnancy: A clinicopathologic analysis of 22 cases and review of the literature. International Journal of Gynecological Cancer Banner. 2006;16(1):8-15.
- Lee-Jones L. Ovary: Germ Cell Tumors. Atlas Genet Cytogenet Oncol Haematol. 2003;7(4):282-288.
- Nick AM, Schmeler K. Adnexal masses in pregnancy. Perinatology. 2010;1:13-19.
- Yen CF, Lin SL, Murk W, Wang CJ, Lee CL, Soong YK, et al. Risk analysis of torsion and malignancy for adnexal masses during pregnancy. Fertility and Sterility. 2009;91(5):1895-1902.
- Karlen JR, Akbari A, Cook WA. Dysgerminoma associated with pregnancy. Obstetrics and Gynecology. 1979;53(3):330-335.
- Hill LM, Johnson CE, Lee RA. Ovarian surgery in pregnancy. Am J Obstet Gynecol 1975;122(5):565-569.
- Ballard CA. Ovarian tumors associated with pregnancy termination patients. Am J Obstet Gynecol 1984;149(4):384-387
- Matsuyama T, Tsukamoto N, Matsukuma K, Kamura T, Kaku T, Saito T. Malignant ovarian tumors associated with pregnancy: report of six cases. Int J Gynaecol Obstet 1989;28(1):61-66.
- Cavaco-Gomes J, Moreira CJ, Rocha A, Mota R, Paiva V, Costa A. Investigation and management of adnexal masses in pregnancy. Scientifica. 2016;2016(3012802): 9.
- Quirk JT, Natarajan N. Ovarian cancer incidence in the United States, 1992-1999. Gynecol Oncol. 2005; 97(2):519-23.
- Kwon YS, Mok JE, Lim KT, Lee IH, Kim TJ, Lee KH, et al. Ovarian cancer during pregnancy: clinical and pregnancy outcome. Journal of Korean Medical Science. 2010;25(2):230-234.
- Horowitz NS. Management of adnexal masses in pregnancy. Clin Obstet Gynecol. 2011;54(4):519-527.
- Kim DS, Park MI. Maternal and fetal survival following surgery and chemotherapy of endodermal sinus tumor of the ovary during pregnancy: a case report. Obstet Gynecol 1989;73(3 Pt 2):503-507.
- Williams S, Blessing JA, Liao SY, Ball H, Hanjani P. Adjuvant therapy of ovarian germ cell tumors with cisplatin, etoposide, and bleomycin: a trial of the Gynecologic Oncology Group. Journal of Clinical Oncology. 1994;12(4):701-706.
- Michener CM, Wu AY. Ovarian Dysgerminomas Follow-Up. In: Huh WK, editor. Medscape; 2015. https://emedicine.medscape.com/article/253701-followup
- Ayhan A, Celik H, Taskiran C, Bozdag G, Aksu T. Oncologic and reproductive outcome after fertility-saving surgery in ovarian cancer. Eur J Gynaecol Oncol. 2003;24(3-4):223-32.
Singhania N, Bhandari P, Gupta AS. Postpartum Collapse In A Case Of Giant Ovarian Dysgerminoma In Pregnancy. JPGO 2019. Vol 6 No. 7. Available from: https://www.jpgo.org/2019/07/postpartum-collapse-in-case-of-giant.html