the aim of this article is to emphasize on a rare occurrence with its clinicopathological features and differential diagnoses in view of the recent literature . a 22 year - old woman presented with an acute onset of lower abdominal pain of 2 days duration . on bimanual pelvic examination , a right adnexal mass was palpated . ultrasonography revealed a right ovarian solid mass measuring 4.5  cm    3.8  cm    3  cm with a low - resistant vascular flow pattern on doppler examination . an adnexal mass , identified on ultra - sound , was explored through a lower midline incision which revealed a solid hemorrhagic mass in the right ovary . macroscopically , the outer surface of the mass was smooth and glistening with a grayish white to purplish tint . 1 ) due to multioculated cystic spaces filled with frank blood . microscopically , most of the ovary was replaced by numerous dilated thin walled vascular channels , of variable size and configuration ( fig . thrombi were noted but there was no necrosis . a follicle cyst and a corpus luteum were also present . the diagnosis of primary ovarian haemangioma , a benign vascular tumor was made . immunohistochemistry , revealed cd 31 & cd 34 positivity of the cells lining the lumina , confirming their vascular nature ( fig . haemangiomas are benign vascular tumors arising from failure in vascular formation , particularly in the canalizing process , forming abnormal vascular channels . the difference between these two types relate to the size of the blood vessels formed . vascular tumors of the female genital tract , especially those of the ovary , are very rare . cyclic changes in the female genital organs during the reproductive period and the asymptomatic nature and small size of the neoplasm have been attributed to explain its rarity of occurrence . although the exact number of ovarian haemangiomas is disputed , the number of well documented cases seems to be 50 or more but does not exceed 60 . large lesions tend to present clinically as adnexal mass , frequently associated with lower abdominal pain , nausea and vomiting , due to torsion or abdominal distension because of the mass itself . only a few of the ovarian haemangiomas have been reported to be associated with massive ascites and elevated serum ca-125 levels clinically mimicking an ovarian carcinoma . preoperative doppler examination of such a lesion may show a low - resistant vascular flow pattern , supporting malignant neoplasia of the ovary . pseudo - meigs syndrome , stromal luteinization , stromal hyperplasia , and thrombocytopenia have also been reported as complications of ovarian haemangioma . the decreased platelet count is regarded as one of the manifestations of kasabach and merritt syndrome , particularly in bilateral cases associated with diffuse abdominopelvic haemangiomatosis . coexistence of non - ovarian neoplasms such as endometrial carcinoma , cervical carcinoma , rectosigmoid carcinoma , and tubal carcinoma has also been reported . although the etiology remains unknown , these lesions have been considered either hamartomatous malformations or true neoplasms in which pregnancy , other hormonal effects , or infection have been implicated as factors , enhancing the growth . it has been suggested that the hyperestrogenism caused by pre - existing stromal luteinization of ovaries may stimulate the development of an ovarian haemangioma due to the growth stimulatory effects of estrogens on vessels and expression of estrogen receptors by haemangiomas . according to another hypothesis , the presence of an expansile ovarian hemangioma induces stromal luteinization by mass effect . these luteinized stromal cells produce androgens , which are subsequently converted to estrogens in adipose tissue , potentially causing unopposed estrogenic stimulation to the endometrium which may present as postmenopausal or dysfunctional uterine bleeding , aching breasts , advanced male type hair loss , and elevated androgen and estradiol levels . macroscopically , ovarian haemangiomas are usually small with size ranging from 5  mm to 24  cm in its greatest diameter . although they may be encountered in any part of the ovary , the medulla and hilum appear to be the most common sites . histologically , they demonstrate either a cavernous , capillary , or mixed type with the cavernous type predominating , as in the present case , in contrast to haemangiomas in other parts of the body . microscopically , they are composed of dilated , blood - filled , generally thin - walled vessels ranging from small to large size , lined by a single layer of flattened endothelial cells . the vessels may be haphazardly located or display a roughly lobular arrangement in a variable amount of connective tissue stroma in which inflammation , hemorrhage and hemosiderin deposits , can be detected . extensive punctate calcification in cavernous haemangioma was reported by kim et al.the present tumor was devoid of calcification probably because of early presentation and surgery . sometimes both preoperative findings and intra - operative structures can be confusing . thus to avoid unnecessary radical surgery for a benign neoplasm , haemangioma should be kept in mind as a differential diagnosis of an ovarian mass before surgery . while the clinical differential diagnoses of ovarian haemangiomas include tubo - ovarian mass , twisted ovarian cyst , and chocolate cyst , the main pathological differential diagnoses are those of vascular proliferations , lymphangioma , and monodermal teratoma composed of a prominent vascular component . haemangioma in the ovary must be differentiated from proliferations of dilated blood vessels of the ovarian hilar region . to define the lesion as a true hemangioma , a mass of vascular channels with minimal amounts of stroma should form a reasonably circumscribed lesion distinct from the remainder of the ovary . one of the main characteristics of these vessels is that they may be calcified or have thickened walls and narrowed lumina due to medial deposition of a hyaline , amyloid - like material . lymphangioma , which was considered in the differential diagnosis of this case because of a similar morphological appearance , was excluded due to the absence of pale eosinophilic homogeneous material within the vascular channels . one of the controversial issues regarding the differential diagnosis involves distinguishing a monodermalteratoma having an angiomatous component from a pure haemangioma . although vascular elements are not generally a component of ovarian teratomas , bilateral ovarian teratomas with a large hemangiomatosis component have been reported in which the lesions were distinguished from a pure hemangioma by the presence of a focus of respiratory epithelium . haemangiomas of the ovary are very rare neoplasms with a wide age range and incidental discovery during operation or autopsy . the risk of kasabach and merritt coagulopathy has to be considered in larger tumors , thus necessitating correct diagnosis and definitive surgical treatment . there is no conflict of interest related to the work among the authors in this study.\ the source of funding was institutional funds of drs tribedi & roy diagnostics laboratory , kolkata . written informed consent was obtained from the patient for publication of this case report and accompanying images . bm , ss ; arq & sr performed the histological examination and prepared the manuscript . arq & sr have supervised all the work and final correction of the manuscript done by them .