{"paper_id":"95dacab7-5fdc-4a9f-98f2-19f58a21c9b6","body_text":"Review began\n 06/20/2025 \nReview ended\n 07/09/2025 \nPublished\n 07/21/2025\n© Copyright \n2025\nKitamura et al. This is an open access\narticle distributed under the terms of the\nCreative Commons Attribution License CC-\nBY 4.0., which permits unrestricted use,\ndistribution, and reproduction in any\nmedium, provided the original author and\nsource are credited.\nDOI:\n 10.7759/cureus.88422\nA Case of Intramural Adenosarcoma With\nSarcomatous Overgrowth Associated With\nAdenomyosis and Endometriosis\nKyohei Kitamura \n \n, \nSachiko Minamiguchi \n \n, \nHiroaki Ito \n, \nYosuke Yamada \n \n, \nYuki Himoto \n,\nKoji Yamanoi \n, \nKen Yamaguchi \n \n, \nHironori Haga \n1.\n Department of Diagnostic Pathology, Kyoto Katsura Hospital, Kyoto, JPN \n2.\n Department of Diagnostic Pathology,\nKyoto University Hospital, Kyoto, JPN \n3.\n Department of Diagnostic Pathology, Fujita Health University Hospital,\nToyoake, JPN \n4.\n Department of Molecular Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo, JPN\n5.\n Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, Kyoto, JPN \n6.\n Department of Obstetrics and Gynecology, Kyoto University Graduate School of Medicine, Kyoto, JPN \n7.\n Department\nof Obstetrics and Gynecology, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, JPN\nCorresponding author: \nSachiko Minamiguchi, \nminami@kuhp.kyoto-u.ac.jp\nAbstract\nAdenosarcoma is a mixed epithelial and mesenchymal neoplasm composed of a malignant mesenchymal\ncomponent and a benign Müllerian glandular component. Although the endometrium is the most common\nprimary site, adenosarcoma can also occur in the cervix, ovaries, fallopian tubes, vagina, or other sites\noutside the genital tract. This report presents the case of a 59-year-old woman with intramural\nadenosarcoma, associated with adenomyosis and endometriosis. Initially, a 4.0-cm uterine mass was\nidentified via magnetic resonance imaging (MRI), and a watchful waiting approach was adopted. However,\nthe mass grew to 8.5 cm over three months. A pathological examination revealed a polypoid mass with\nmalignant spindle cells and benign glandular epithelium, confirming adenosarcoma with sarcomatous\novergrowth. The endometrium showed no abnormalities, and the tumor appeared contiguous with\nadenomyosis and endometriosis in the myometrium and serosa of the uterine corpus, respectively. This case\nhighlights the importance of considering adenosarcoma in the differential diagnosis of malignant\ntransformation from adenomyosis or endometriosis.\nCategories:\n Obstetrics/Gynecology, Radiology, Pathology\nKeywords:\n adenomyosis, adenosarcoma, endometriosis, sarcomatous overgrowth, uterus\nIntroduction\nAdenosarcoma is a mixed epithelial and mesenchymal neoplasm composed of a malignant mesenchymal\ncomponent and a benign Müllerian glandular component. The first case of adenosarcoma was described in\n1974 by Clement and Scully \n[1]\n. Although the endometrium is the most common primary site, adenosarcoma\ncan also occur in the cervix, ovaries, fallopian tubes, vagina, or other sites outside the genital tract. Some of\nthese have been reported to be associated with adenomyosis or endometriosis. Those cases are so rare that it\nis sometimes difficult to properly diagnose them preoperatively. We herein report a case of intramural\nadenosarcoma associated with adenomyosis and endometriosis.\nCase Presentation\nA 59-year-old woman was referred to our hospital because of lower abdominal pain and a uterine mass.\nAdenomyosis has been previously reported. Magnetic resonance imaging (MRI) showed a 4.0-cm mass in the\nuterine corpus, especially in the muscle layer. Since malignancy could not be ruled out, surgical intervention\nwas proposed. However, the patient preferred a watchful waiting approach. Approximately one month later,\nthe patient experienced worsening abdominal pain, and three months later, follow-up MRI showed that the\nmass had grown from 4.0 cm to 8.5 cm. T2-weighted images showed that the tumor was located in\nintramuscular to sub-serosal and extra-serosal areas, away from the endometrium (Figures \n1A\n, \n1B\n). The\ntumor showed heterogeneous diffusion restriction on diffusion-weighted images and apparent diffusion\ncoefficient maps. MRI also suggested intratumoral hemorrhage (Figures \n1C\n-\n1E\n). Clinically, uterine sarcoma\nor carcinoma associated with adenomyosis was suspected. Abdominal total hysterectomy, bilateral salpingo-\noophorectomy, and partial resection of the sigmoid colon were performed.\n1,\n2\n3,\n2\n2\n4,\n2\n5\n6\n7,\n6\n2\n \nOpen Access Case Report\nHow to cite this article\nKitamura K, Minamiguchi S, Ito H, et al. (July 21, 2025) A Case of Intramural Adenosarcoma With Sarcomatous Overgrowth Associated With\nAdenomyosis and Endometriosis. Cureus 17(7): e88422. \nDOI 10.7759/cureus.88422\n\nFIGURE\n 1: MRI findings of the tumor\n(A), (B) T2-weighted image of the pelvis. (A) Axial and (B) sagittal views. Arrowheads show the endometrium, and\nthe arrow shows the uterine cervix. The tumor was located from the myometrium to the subserosa and\nextraserosa (asterisk).\n(C-E) Axial diffusion-weighted image (C), apparent diffusion coefficient (ADC) map (D), and fat-saturation T1-\nweighted image (E). The tumor is indicated by the asterisk. Hemorrhage was identified (arrow). (C) and (D) show\nheterogeneous diffusion restrictions.\nA gross examination of the uterus showed an 11.0×8.0×3.5-cm polypoid mass protruding from the\nmyometrium toward the outer surface of the posterior and right lateral uterine wall (Figure \n2A\n). The cut\nsurface was solid and yellowish-white, with hemorrhage at the margins. In the uterine corpus, although\nthere was no abnormality in the endometrium, a 2.7-cm intramural cystic cavity was observed, which\nextended outside the uterus and was continuous with the tumor (Figure \n2B\n).\n \n2025 Kitamura et al. Cureus 17(7): e88422. DOI 10.7759/cureus.88422\n2\n of \n6\n\nFIGURE\n 2: Macroscopic and microscopic findings of the tumor\n(A) Gross examination shows an 11.0 x 8.0 x 3.5 cm polypoid tumor polypoid mass protruding from the\nmyometrium toward the outer surface of the posterior and right lateral uterine wall (yellow arrow).\n(B) Cut surface (yellow dotted line in A): No abnormality is identified in the endometrium (arrowhead). A 2.7-cm\ncystic cavity is observed in the myometrium of the uterus (white arrow).\n(C) Microscopically, the polypoid mass is entirely composed of malignant spindle cells with nuclear pleomorphism.\n(D) In the high-power field, malignant spindle cells show periglandular cuffing.\nMicroscopically, the polypoid mass consisted entirely of malignant spindle cells with nuclear pleomorphism\n(Figure \n2C\n). The mitotic count was 15/mm\n2\n and necrosis was present. In the intramural cystic cavity, the\ntumor showed a phyllode-like architecture with a benign glandular epithelium and a malignant\nmesenchymal component. Malignant spindle cells showed characteristic periglandular cuffing under high-\npower fields (Figure \n2D\n). Immunohistochemically, the tumor was positive for ER and partially positive for\nCD10, and p53 was overexpressed. The tumor was negative for cyclin D1, desmin, alpha SMA, myogenin, and\nBCOR. Based on these findings, the patient was diagnosed with adenosarcoma with sarcomatous\novergrowth. Disease-specific findings were not observed in the endometrium. There was no involvement of\nthe colon, bilateral adnexa, or cervix.\nNon-neoplastic glandular epithelium was observed in the myometrium and serosa of the uterine corpus.\nThis was ectopically located endometrial tissue, which was consistent with adenomyosis and endometriosis.\nThere was infiltrative growth of tumor cells around them (Figures \n3A\n-\n3C\n). The cells were differentiated\nusing p53 immunohistochemistry. Immunohistochemistry for p53 showed overexpression in adenosarcoma\nand wild-type expression in adenomyosis and endometriosis (Figure \n3D\n). The tumor, adenomyosis, and\nendometriosis appeared to be contiguous. This finding suggests that the tumor was associated with\nadenomyosis and endometriosis.\n \n2025 Kitamura et al. Cureus 17(7): e88422. DOI 10.7759/cureus.88422\n3\n of \n6\n\nFIGURE\n 3: Adenosarcoma, adenomyosis, and endometriosis\n(A) In a low-power field, adenomyosis/endometriosis (blue squares) can be observed around the tumor (red\nsquares).\n(B) Adenomyosis/endometriosis.\n(C) Adenosarcoma; malignant spindle cells proliferate with benign glandular components.\n(D) Immunohistochemically, p53 is overexpressed in the tumor cells of C.\nBecause this case exhibited sarcomatous overgrowth, the patient was treated postoperatively with\ndoxorubicin alone. However, approximately five months after surgery, radiological imaging revealed\nmultiple nodules in the pelvis, which were suspected to represent recurrence. The patient subsequently\ndeveloped small bowel obstruction, and surgical resection of the pelvic mass was performed.\nHistopathological examination confirmed a high-grade sarcoma, consistent with recurrence. Then the\npatient was treated with ifosfamide and cisplatin. The treatment showed a marked effect, achieving a near-\ncomplete response on imaging. Four months later, the pelvic lymph nodes and pelvic masses enlarged again.\nGiven the prospect of prolonged treatment, eribulin was selected as the next line of therapy. As it was\nineffective, however, the regimen was switched back to ifosfamide and cisplatin, which is still being\nadministered. Moreover, palliative radiation therapy was carried out and achieved a therapeutic effect.\n \n2025 Kitamura et al. Cureus 17(7): e88422. DOI 10.7759/cureus.88422\n4\n of \n6\n\nDiscussion\nAdenosarcoma is a biphasic neoplasm composed of benign epithelial and malignant stromal components.\nThis tumor accounts for 5%-10% of all uterine sarcomas. While it is most often seen in perimenopausal and\npostmenopausal women (median age, 50-59 years), it can occur at all ages (range 15-90 years) \n[2]\n.\nClinically, the most common symptom is abnormal vaginal bleeding. Other common symptoms include\nvaginal discharge, abdominal pain, nonspecific urinary symptoms, and palpable pelvic mass \n[2]\n. In our case,\nbecause the tumor arose not in the endometrium but in the myometrium, the patient did not show vaginal\nbleeding.\nFrom a pathological point of view, the tumor shows phyllodiform cleft-like or dilated glands lined by benign\nendometrial or ciliated epithelium, surrounded by a distinct cuff of neoplastic stroma (periglandular\ncuffing). The sarcomatous component is most often the nondescript homologous type, but\nrhabdomyosarcomatous differentiation is possible \n[3]\n. The sarcomatous component may overgrow the\nepithelial component, referred to as sarcomatous overgrowth. Adenosarcoma with sarcomatous overgrowth\nis defined as an adenosarcoma in which the sarcomatous component constitutes more than 25% of the\ntumor. Adenosarcomas with sarcomatous overgrowth are found in 8-54% of cases \n[4]\n.\nAdenosarcomas associated with adenomyosis or endometriosis are very rare and have only been described in\na small number of case reports \n[5-7]\n. In these reports, the age of onset was mainly in the 30s to 50s, with a\nfew cases in which adenomyosis or endometriosis was noted preoperatively on imaging. The incidence of\nadenosarcoma arising from endometriosis is reported to be 0.3% in patients with endometriosis \n[8]\n.\nMRI findings of adenosarcoma in the endometrial cavity typically present as solitary, exophytic, polypoid\nmasses. The mass consists of heterogeneous solid components with tiny cysts corresponding to glandular\ncavities that show high signal intensity on T2-weighted images. The solid component shows a\nheterogeneous high signal intensity relative to the myometrium on T2-weighted images. Hemorrhagic\nnecrosis with high signal intensity on T1-weighted images is common, particularly when sarcomatous\novergrowth is present \n[9]\n. Reports of MRI findings of intramural adenosarcomas are rare. Some studies have\nshown that intramural adenosarcoma exhibits similar features to adenosarcoma in the endometrium \n[10]\n.\nIn terms of the pathological differential diagnosis, it is important to distinguish adenosarcoma from other\nuterine sarcomas such as endometrial stromal sarcoma and leiomyosarcoma. Considering the\nhistopathological features, periglandular cuffing is key to the diagnosis. Immunohistochemistry is also\nuseful for differentiating adenosarcoma from other types of sarcomas. Adenosarcomas are often positive for\nCD10, ER, and PR, and adenosarcomas with sarcomatous overgrowth frequently exhibit abnormal p53\nexpression. In the present case, the histopathological and immunohistochemical features were typical of\nadenosarcoma, although the tumor had grown intramurally. To summarize the differential diagnoses in this\ncase, uterine sarcoma and carcinoma associated with adenomyosis were suspected clinically, and other types\nof sarcomas were the main pathological differential diagnoses.\nThere are some reports on the prognosis of adenosarcomas arising in the endometrium. The prognosis is\ngenerally favorable in comparison to other gynecological sarcomas. Sarcomatous overgrowth is a predictor\nof worse progression-free survival (PFS) and overall survival (OS). It is reported that the median PFS and OS\nare 29.4 and 55.4 months, respectively, in patients with sarcomatous overgrowth, compared to 105.9 and\n112.4 months in patients without sarcomatous overgrowth \n[11]\n. Moreover, lymphovascular invasion,\nnecrosis, and the presence of heterologous elements, including rhabdomyoblastic differentiation, are\nprognostic markers \n[4]\n. Few reports have described the prognosis of adenosarcoma arising from adenomyosis\nor endometriosis. Some studies have suggested that adenosarcoma arising in endometriosis has a favorable\nprognosis \n[12]\n. In our case, the tumor recurred five months after surgery, suggesting a poor prognosis. This\nis probably due to the presence of sarcomatous overgrowth. However, ifosfamide and cisplatin therapy was\nhighly effective. Further investigation is required regarding prognosis and treatment strategies.\nConclusions\nThis report describes a case of uterine intramural adenosarcoma associated with adenomyosis and\nendometriosis. Adenosarcomas associated with adenomyosis or endometriosis are very rare. However, as\ndemonstrated in this case, both carcinoma and adenosarcoma should be considered in the differential\ndiagnosis of malignant transformation from adenomyosis or endometriosis. While the prognosis of\nadenosarcoma associated with adenomyosis or endometriosis is not well defined, the presence of\nsarcomatous overgrowth, as in our case, can indicate a poorer prognosis.\nAdditional Information\nAuthor Contributions\nAll authors have reviewed the final version to be published and agreed to be accountable for all aspects of the\nwork.\n \n2025 Kitamura et al. Cureus 17(7): e88422. DOI 10.7759/cureus.88422\n5\n of \n6\n\nConcept and design:\n  \nKyohei Kitamura, Sachiko Minamiguchi, Hiroaki Ito\nAcquisition, analysis, or interpretation of data:\n  \nKyohei Kitamura, Sachiko Minamiguchi, Hiroaki Ito,\nYosuke Yamada, Yuki Himoto, Hironori Haga, Ken Yamaguchi, Koji Yamanoi\nDrafting of the manuscript:\n  \nKyohei Kitamura, Sachiko Minamiguchi, Hiroaki Ito\nCritical review of the manuscript for important intellectual content:\n  \nSachiko Minamiguchi, Hiroaki\nIto, Yosuke Yamada, Yuki Himoto, Hironori Haga, Ken Yamaguchi, Koji Yamanoi\nSupervision:\n  \nHironori Haga\nDisclosures\nHuman subjects:\n Informed consent for treatment and open access publication was obtained or waived by all\nparticipants in this study. \nConflicts of interest:\n In compliance with the ICMJE uniform disclosure form, all\nauthors declare the following: \nPayment/services info:\n All authors have declared that no financial support\nwas received from any organization for the submitted work. \nFinancial relationships:\n All authors have\ndeclared that they have no financial relationships at present or within the previous three years with any\norganizations that might have an interest in the submitted work. \nOther relationships:\n All authors have\ndeclared that there are no other relationships or activities that could appear to have influenced the\nsubmitted work.\nReferences\n1\n. \nClement PB, Scully RE: \nMüllerian adenosarcoma of the uterus. 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