Fallopian tube cavernous haemangioma found during the caesarean section of a woman with a history of endometriosis: a case report and literature review

A white, 39-year-old, nulliparous, pregnant woman was admitted following spontaneous rupture of membranes during outpatient induction of labour for postdates, respecting and supporting maternal informed decisions. The gestational age, on the day of admission, was 42 weeks +0 days. Earlier dates of induction of labour (from 41 weeks of gestation for postdates) and membrane sweeps were offered but declined. The background history involved an in vitro fertilization (IVF) pregnancy with a fresh embryo (own egg retrieval 15 April and estimated delivery date 6 January the following year) and a positive vaginal swab for Group B Streptococcus . The patient's medical and gynaecological history included endometriosis, adenomyosis, irritable bowel syndrome (IBS), and asthma. Endometriosis had been confirmed in the past radiologically and the patient had undergone laparoscopic left ovarian cystectomy (endometrioma). Routine antenatal ultrasound examinations at 12, 20, and 36 weeks of gestation showed no adnexal masses or abnormalities. No dedicated pelvic magnetic resonance imaging (MRI) was performed during pregnancy as there were no clinical indications. The patient was asymptomatic throughout pregnancy. The patient stayed on the delivery suite for approximately 14 h and had an oxytocin infusion due to inadequate progress. After 8 h on oxytocin infusion, in view of the delayed 1st stage of labour and maternal request, an emergency caesarean section was performed under spinal anesthesia, with no complications. The neonate was in good health, with Apgar scores of 9 at 1 min and 10 at 5 min, and arterial pH 7.32, base excess −0.8, lactate 2.5 and venous pH 7.36, base excess −1.4 and lactate 2.1. The birthweight was 4040 g. Intraoperatively, the uterus was found to have a small subserosal 1 × 2 cm fibroid; the ovaries were normal, as was the right tube. On the left tube, at the fimbrial end, there was a brown-colored nodule measuring 1 × 1 cm, which was ligated, excised with the patient's consent, and sent to the histology laboratory. The decision to excise the lesion was made due to its unusual brown coloration and firm consistency, which raised suspicion for a potential neoplastic process that warranted histopathological evaluation, with the patient's consent. Given the patient's history of endometriosis and adenomyosis, several differential diagnoses were considered for the brown-colored fimbrial nodule: endometriotic implant (primary consideration given known endometriosis and brown coloration), paratubal cyst or hydatid of Morgagni (common benign adnexal findings), tubal pregnancy remnant (unlikely but considered given reproductive history), primary fallopian tube neoplasm (adenomatoid tumor or carcinoma requiring exclusion), and inflammatory nodule (secondary to previous laparoscopic surgery). Intraoperative frozen section examination was not performed, partly because the procedure was conducted out of hours, when frozen section services were not readily available, and partly because the small size of the lesion (1 × 1 cm) made it technically challenging for frozen section analysis; the clinical decision was made to proceed with complete excision to ensure adequate tissue sampling for definitive histopathological diagnosis. The patient recovered well postoperatively and was discharged the following day. At 8-week telephone follow-up, the patient remained asymptomatic, with no pelvic pain or abnormal bleeding. Further imaging was deemed unnecessary given the benign nature of the lesion and complete excision. The histopathology results were discussed and explained to the patient. The histopathological report showed, macroscopically, a segment of fallopian tube measuring 14 × 5 mm. Upon slicing, no focal lesion was identified. Microscopically, the sections showed a circumscribed and encapsulated lesion ( Fig. 1 ) composed of proliferating, variably sized, dilated, and thin-walled vessels ( Fig. 2 ), in some of which focal fibrin thrombi could be seen ( Figs. 3 and Fig. 4 ). The vessels were lined by a single layer of flattened endothelial cells ( Fig. 5 ). The preservation of the specimen was not optimal, but there was no evidence of cytologic atypia or mitotic activity. These findings were consistent with a fallopian tubal cavernous haemangioma. Fig. 1 Low-power image of fallopian tube showing a well circumscribed lesion. Fig. 1 Fig. 2 10× magnification showing proliferating blood vessels of varying sizes. Fig. 2 Fig. 3 10× magnification demonstrating fibrin within the vessels. Fig. 3 Fig. 4 10× magnification demonstrating fibrin within the vessels. Fig. 4 Fig. 5 High-power magnification shows single layer of flattened endothelial cells. Fig. 5 Low-power image of fallopian tube showing a well circumscribed lesion. 10× magnification showing proliferating blood vessels of varying sizes. 10× magnification demonstrating fibrin within the vessels. 10× magnification demonstrating fibrin within the vessels. High-power magnification shows single layer of flattened endothelial cells. While immunohistochemical markers such as CD31, CD34, and SMA staining would have provided confirmation, these were not performed due to suboptimal tissue preservation following fixation. However, the diagnosis of cavernous haemangioma was based on classic histopathological features, including dilated thin-walled vessels lined by flattened endothelial cells with focal fibrin thrombi, which are considered diagnostic for cavernous haemangioma. The diagnosis was confirmed by two senior consultant histopathologists through independent review of the slides, ensuring diagnostic accuracy despite the absence of immunohistochemical confirmation. Regarding alternative diagnoses, endometriosis-related lesions were considered given the patient's history. However, the lesion lacked characteristic endometriotic features such as endometrial glands, stroma, or hemosiderin-laden macrophages. The possibility of an undeveloped embryonic structure from IVF was also considered, but the lesion's vascular architecture was inconsistent with embryonic or placental tissue, which would typically show chorionic villi, trophoblastic elements, or embryonic structures.

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Written informed consent was obtained from the patient for publication of the case report and accompanying images.

This report presents a case of fallopian tube cavernous haemangioma, a very rare benign tumor, which was found during a caesarean section. The patient's medical and gynecology histories included endometriosis, adenomyosis, and IBS. The aetiology of haemangiomas is still unclear, but it is commonly believed that the growth of fallopian tube haemangiomas is stimulated by oestrogen, which promotes blood vessel growth. The possible link between endometriosis and haemangiomas would could be a basis for future research. Most haemangiomas, which are mainly asymptomatic, are discovered incidentally during surgeries for other conditions or complications. To the authors' best knowledge, this is the first report of a case of cavernous haemangioma of the fallopian tube identified in pregnancy.

Fallopian tube haemangiomas are rare benign vascular tumours; only 16 documented cases could be found in the literature. Most of these tumours, ranging from 2 to 10 mm in size, were asymptomatic and discovered incidentally during surgeries for other conditions. Therefore, it is likely that the actual incidence of fallopian tube haemangiomas is much higher [ 11 ]. Most of these vascular lesions appear during the second and third decades of life, and parity does not seem to have a significant impact [ 13 ]. The aetiology of haemangiomas remains unclear. Although they are generally considered to be of congenital origin, they can also develop in adults from developmental remnants that retain the capacity for later proliferation [ 14 ]. The growth of haemangiomas in the genital tract is also believed to be influenced by hormonal effects, such as the growth-stimulating effects of oestrogen on blood vessels, which have been confirmed through immunohistochemistry demonstrating ooestrogen receptors. Also, Bonetti et al. hypothesized that oestrogen might play a role in the development of haemangiomas due to the presence of oestrogen receptors in endothelial cells. In their study, they found that all three tumours were immunoreactive for CD31, CD34, and factor VIII-related antigens [ 15 ]. Additionally, ovarian haemangiomas can exert a mass effect on the ovary, causing stromal luteinization and the production of androgens. These androgens are then converted to oestrogen peripherally, potentially affecting the endometrium and myometrium. This mechanism could be one reason for adenomyosis in this case [ 5 ]. Furthermore, pregnancy and contraceptive oral pills may promote the growth or exacerbate the symptoms of an existing lesion, suggesting a hormonal influence. There is a possibility that these changes can lead to actual blood vessel growth or angiogenesis in pre-existing vascular anomalies [ 14 , 16 ]. The patient in this case report had a history of adenomyosis, IBS, and endometriosis. Adenomyosis and endometriosis are interrelated conditions whose overlapping clinical and pathophysiological features have led many researchers to consider them as two manifestations within a spectrum of uterine disorders. Endometriosis is a chronic, oestrogen-dependent inflammatory condition characterized by the presence of endometrial tissue outside the uterine cavity. Both endometriosis lesions and haemangiomas are influenced by the high hormonal surge during pregnancy and may share overlapping pathophysiological mechanisms. Notably the literature has highlighted a potential association between haemangiomas and endometriosis, although the exact relationship remains to be fully elucidated. Several case reports and reviews have noted that cavernous haemangiomas can coexist with endometriotic lesions, particularly in the pelvic region, where altered angiogenic factors may play a role. For instance, locations that are commonly associated with haemangiomas are also frequent sites for endometriosis such as hepatic haemangiomas associated with endometriosis [ 17 , 18 ], cavernous haemangiomas mimicking endometriosis found on broad ligament of uterus and in the endometrial cavity [ 19 , 20 ] and rectal haemangioma mimicking uterosacral endometriosis [ 21 ]. The aberrant vascular proliferation seen in haemangiomas might share common pathogenic pathways with the neovascularization observed in endometriosis. However, the literature is limited by the small number of reported cases, and definitive mechanistic links between these conditions have yet to be established. Further research is required to clarify whether this co-occurrence is coincidental or reflects shared underlying molecular mechanisms, particularly in the context of altered local angiogenesis related to inflammatory and hormonal factors. Endometriosis is linked to a nearly three-fold increase in the risk of IBS, with over 20 % of women with endometriosis also having IBS. The relationship between endometriosis and IBS remains unclear. One theory suggests an immunological link through the increased activation of mast cells observed in both conditions. Key features of this immunological connection include abnormal levels of inflammatory cytokines and immune cell activation in the peritoneal cavity. Retrograde menstruation, which involves the flow of menstrual blood containing endometrial cells into the pelvic cavity, could potentially trigger symptoms of IBS. Another theory suggests a hormonal linkage between these two disorders. This connection involves gonadotropin-releasing hormone-containing neurons and receptors for luteinizing hormone within the pelvic organs and the enteric nervous system. It is hypothesized that the pain experienced by some women with IBS may result from female sex hormones, as studies have shown that IBS symptoms often worsen during menstruation [ 22 , 23 ]. Differential diagnoses for fallopian tube haemangiomas include lymphangiomas, vascular leiomyomas, mesothelioma, endometriosis, and adenomatoid tumours. Histologically, distinguishing haemangiomas from these neoplasms and fallopian tube cancer is not challenging. However, an immunohistochemical study is recommended for reliable confirmation of the diagnosis. Immunohistochemically, haemangiomas test positive for CD31, CD34, and smooth muscle actin (SMA). Lymphangiomas show positivity for LYVE-1. Both adenomatoid tumours and mesotheliomas exhibit positivity for mesothelial markers, including calretinin, D2–40, and WT-1 protein. Vascular leiomyomas are positive for SMA, desmin, and caldesmon [ 10 , 11 , 21 , 24 ]. In most instances, haemangiomas are small, asymptomatic, and discovered incidentally. Larger lesions can present with an ovarian torsion, acute abdomen, or rupture leading to hemoperitoneum. In this case, the haemangioma was found incidentally and did not produce any specific signs or symptoms due to its size and location. Most fallopian tube haemangiomas have been incidentally discovered in the left fallopian tube. However, three cases of cavernous haemangiomas have presented with an acute abdomen due to hemoperitoneum. Histologically, cavernous haemangiomas are characterized by irregularly dilated, thick-walled vascular spaces lined with endothelium, whereas capillary haemangiomas consist of proliferating endothelial cells forming lumina with a single layer of endothelial lining and red blood cells [ 10 ]. Diagnosis prior to a surgical procedure can be very challenging. Transvaginal ultrasound or MRI/CT of the pelvis can be used to assess the size and extent of the haemangioma and monitor any changes, when haemangiomas are causing symptoms which would be suggestive of considerable size. Although soft-tissue lesion characterization is not always possible, MRI is the best imaging modality for lesion characterization. Haemangiomas, as vascular lesions, can consist of serpentine vessels, fat regions, and phleboliths. Detecting phleboliths, which are localized dystrophic mineralizations within a thrombus, on radiographs or CT scans can assist in characterization. On MRI, haemangiomas can appear either well defined or with indistinct borders, exhibiting varying levels of hyperintense T1 signals due to reactive fat overgrowth or hemorrhage. Typically, haemangiomas display circular, linear, or serpentine high T2 signal intensity, resulting from slow blood flow within the vascular channels [ 6 ]. On ultrasound, haemangioma can appear as a well-defined solid mass with regular shape, particularly if colour Doppler sonography reveals a highly vascularized lesion with significant blood flow [ 25 ]. In a majority of cases it appears as a hyperechoic lesion, but there are cases of hypoechoic appearance [ 26 ]. In cases of small haemangiomas, especially when they cause no symptoms, pre-procedural diagnosis is nearly impossible and usually those haemangiomas are seen for the first time intraoperatively. Macroscopic diagnosis during surgery is unlikely. Hence, a frozen section examination or a biopsy, especially for small lesions, is important. Misinterpreting a benign tumor may result in unnecessary surgical procedures causing fertility loss, while overlooking a malignant process can endanger life. Involvement of a senior gynaecologist, intraoperatively, especially in women of reproductive age, is recommended prior to any intervention. Sparing surgery is an appropriate treatment for fallopian tube haemangioma, as no relapses have been documented in previous cases. However, follow-up assessment can be considered if any symptoms are present [ 5 , 10 , 11 , 27 ]. This case highlights several critical areas warranting future investigation, particularly the potential relationship between endometriosis and vascular malformations. The concurrent presence of endometriosis and cavernous haemangioma in this patient raises important questions about shared pathogenic mechanisms, including common angiogenic pathways, hormonal responsiveness, and inflammatory mediators. Future research should explore whether patients with endometriosis have an increased predisposition to vascular lesions through case-control studies and molecular analysis of angiogenic factors such as VEGF, bFGF, and angiopoietins. Additionally, the hormonal influences during pregnancy on pre-existing vascular lesions require systematic investigation, particularly regarding the effects of oestrogen and progesterone on haemangioma growth and behavior. Long-term prospective studies tracking fertility outcomes and recurrence rates following fallopian tube haemangioma excision would provide valuable clinical guidance. Finally, development of specific imaging characteristics to identify these rare lesions preoperatively could improve surgical planning and patient counseling, while genetic studies investigating shared susceptibility loci between endometriosis and vascular malformations may reveal novel therapeutic targets.

This article was not commissioned and was peer reviewed. Dudley Robinson, an editor of Case Reports in Women's Health who is affiliated to the same institution as some of the authors, was not involved in editorial consideration of the manuscript and was blinded to the process.

Konstantinos Malligiannis Ntalianis contributed to patient care, acquiring and interpreting the data and drafting the manuscript. Gladys Hulipas contributed to patient care, conception of the case report and undertaking the literature review. Hemapriya Mohanraj contributed to patient care, acquiring and interpreting the data and drafting the manuscript. Christina Anastasia Resta contributed to the literature review and revising the article critically for important intellectual content. Anitha Nayar contributed to patient care and revising the article critically for important intellectual content. Sahathevan Sathiyathasan contributed to patient care and revising the article critically for important intellectual content. All authors approved the final submitted manuscript.

Haemangiomas are tumours of vascular origin and are commonly found in soft tissues and the skin [ 1 ]. Vascular malformations are a diverse group of lesions typically resulting from congenital errors in vessel morphogenesis, characterized by cellular turnover without true proliferation [ 2 ]. Haemangiomas are classified as capillary type (small blood vessels) and cavernous type (large blood vessels). The International Society for the Study of Vascular Anomalies (ISSVA) classifies vascular lesions based on morphological and immunohistochemical markers. Capillary haemangiomas are considered “difficult to classify” because their morphological characteristics do not align with any specific type in the ISSVA classification [ 3 ]. Vascular tumours in female pelvic organs are exceedingly rare [ 4 ]. Despite most of these lesions being discovered incidentally, they can clinically and radiologically resemble a variety of benign and malignant conditions [ 5 ]. Clinically, haemangiomas may present with a bluish discoloration of the skin and a history of size fluctuations. Pain can occur post-exercise due to the diversion of blood flow from surrounding tissues into the haemangioma. Imaging reveals haemangiomas containing serpentine vessels, fat, smooth muscle, hemosiderin, and phlebolith [ 6 , 7 ]. Histologically, haemangiomas are categorised by the dominant type of vascular channel: capillary, cavernous, arteriovenous, and venous. Cavernous haemangiomas are found in the skin, liver, kidneys, breast, brain, bone, and skeletal muscle. They are characterized by cavern-like vascular spaces larger than those in capillary haemangiomas, lined with non-atypical endothelial cells. Haemangiomas are rare in female genital organs except for the vulva [ 1 , 8 ]. Haemangiomas in female reproductive organs, especially in the fallopian tubes, are extremely rare. The first description was provided by Ragins and Crane in 1947 [ 9 ]. Katiyar et al. reported on capillary haemangiomas, noting eleven documented cases of cavernous haemangiomas in the fallopian tubes of patients aged 13 to 77 years up to 2016. Since then, four additional cases of fallopian tube haemangiomas have been published, including three capillary haemangiomas [ 10 , 11 ]. So far, no link has been found between haemangiomas and infertility. This report presents a case of a fallopian tube cavernous haemangioma in a 39-year-old woman. To the authors' best knowledge, this represents the first published case of cavernous haemangioma of the fallopian tube identified in pregnancy. This article was previously posted on the Research Square preprint server on 03 Jul, 2024 [ 12 ].

The authors declare that they have no competing interest regarding the publication of this case report.