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Year : 2021  |  Volume : 64  |  Issue : 4  |  Page : 802-805
Uterine collision tumor of endometrial stromal sarcoma and endometrioid adenocarcinoma: A rare case report and review of literature

1 Department of Histopathology, Lab Medicine, Artemis Hospitals, Gurugram, Haryana, India
2 Department of Surgical Oncology, Tata Memorial Center, Varanasi, Uttar Pradesh, India

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Date of Submission05-Jun-2020
Date of Decision09-Aug-2020
Date of Acceptance17-Feb-2021
Date of Web Publication20-Oct-2021


Collision tumors are characterized by occurrence of two or more histologically distinct tumor types at the same anatomic site. Collision tumors have been reported in various organs, such as esophagus, stomach, colon, kidney, lung, skin, thyroid, breast, ovary and uterus. Uterine collision tumors of epithelial and mesenchymal origin are rare and often underrecognized. We report a rare concurrent occurrence of endometrial stromal sarcoma and endometrioid adenocarcinoma in a 65-year-old female. It is important to differentiate collision tumors from carcinosarcoma due to impact on clinical management and prognosis. Extensive gross sampling and careful morphological examination aided by immunohistochemical studies is necessary for the diagnosis of this rare entity. This case report aims to increase the awareness of this rare pathological entity with discussion on the management issue based on review of literature. This is the first case in Indian literature to the best of our knowledge.

Keywords: Carcinosarcoma, collision tumor, endometrial stromal sarcoma, endometrioid adenocarcinoma

How to cite this article:
Sharma S, Vasdev N, Pandey D. Uterine collision tumor of endometrial stromal sarcoma and endometrioid adenocarcinoma: A rare case report and review of literature. Indian J Pathol Microbiol 2021;64:802-5

How to cite this URL:
Sharma S, Vasdev N, Pandey D. Uterine collision tumor of endometrial stromal sarcoma and endometrioid adenocarcinoma: A rare case report and review of literature. Indian J Pathol Microbiol [serial online] 2021 [cited 2021 Nov 28];64:802-5. Available from: https://www.ijpmonline.org/text.asp?2021/64/4/802/328573

   Introduction Top

Mixed epithelial and mesenchymal neoplasms of uterine corpus are rare. These neoplasms are characterized by proliferation of both mesenchymal and epithelial components and each of these components may be benign or malignant. As per WHO, these include a spectrum of neoplasms including adenomyomas, atypical polypoid adenomyomas, adenofibromas, adenosarcomas and carcinosarcomas.[1] Carcinosarcoma is the most common of these, characterized by mixture of both malignant epithelial and mesenchymal elements. Molecular studies have shown that these two components are monoclonal in about 80–90% of cases.[2] The remaining 10–20% cases, composed of topographically separate carcinoma and sarcoma elements, are believed to be biclonal and better categorized as collision tumors in which epithelial and mesenchymal components develop from two independent cell populations.[3] Uterine collision tumors are infrequent and reported as rare case reports only. Their clinicopathologic features and relatively better prognosis than similarly staged carcinosarcoma, suggest that they should be distinguished from carcinosarcoma. The present case highlights the rare collision tumor of endometrial stromal sarcoma and endometrioid adenocarcinoma and emphasizes its differentiation from carcinosarcoma due to the impact on clinical management and prognosis.

   Case Report Top

A 65-year-old female presented to the outpatient department with chief complaint of postmenopausal bleeding of two-week duration. Per vaginum examination revealed a fleshy growth in the cervix with free parametrium on both sides. MRI pelvis showed an ill-defined polypoidal enhancing endometrial lesion in the fundal region, measuring approximately 3.1 × 1.3 cm with contiguous enhancement along the endometrial lining extending into the proximal cervix [Figure 1]a. Endometrial biopsy showed endometrial stromal tumor with focal glandular crowding and nuclear atypia. Subsequently, hysterectomy with bilateral salpingo-oophorectomy was performed. Intraoperatively the uterus was bulky and few enlarged lymph nodes were present around iliac vessels. The frozen section analysis of the hysterectomy specimen revealed high-grade uterine sarcoma. The patient then underwent bilateral pelvic-paraaortic lymphadenectomy and omentectomy for staging purpose, considering a possibility of carcinosarcoma also, based on the endometrial biopsy report which showed focal epithelial atypia. The entire surgical specimen was analyzed in the Department of Histopathology. Gross examination showed a grey-white polypoidal mass in the fundus and body of the uterus measuring 4 cm × 3 cm × 2 cm with fleshy grey-brown cut surface. The adjacent endometrium was thickened up to 0.5 cm [Figure 1]b. Extensive gross sampling was performed from both the polypoidal mass and thickened endometrium. Microscopic examination revealed two separate tumor components. One component comprised sheets of atypical spindle cells, infiltrating and replacing the myometrial smooth muscle fibers superficially [Figure 2]a. These cells show spindled to ovoid vesicular nuclei with indistinct cell boundaries [Figure 2]b. Brisk mitotic activity (Mitosis >20/10 HPF) was seen [Figure 2]c. Adjacent to it, there was another component of adenocarcinoma, composed of closely packed and fused glands, lined by stratified columnar epithelium [Figure 3]a and [Figure 3]b. These lining cells showed moderate pale eosinophilic cytoplasm with mild to moderate nuclear atypia [Figure 3]c. No solid component was found. Superficial invasion into the myometrium was noted [Figure 3]b. Areas of endometrial intraepithelial neoplasia were also seen. The morphologic differential diagnosis of carcinosarcoma was considered, although no admixture of the two components was found after extensive sampling. On immunohistochemistry, the spindle cell component was non-immunoreactive for PanCK & EMA, which raised our suspicion for another differential diagnosis of collision tumor as carcinosarcomas show immunoreactivity to these epithelial markers in both sarcoma and carcinoma component. On further assay, the sarcoma component was variably immunoreactive for CD10 [Figure 2]e, Cyclin D1 [Figure 2]f and non-immunoreactive for ER [Figure 2]d, Desmin and HMB45. Based on this, diagnosis of high grade endometrial stromal sarcoma was considered, ruling out carcinosarcoma, leiomyosarcoma and malignant perivascular epithelioid cell tumor. As the adenocarcinoma component was immunoreactive for PanCK [Figure 3]d, EMA and ER [Figure 3]e with non-immunoreactivity for p53 [Figure 3]f, the morphologic diagnosis of endometrioid adenocarcinoma FIGO grade I was confirmed, ruling out the possibility of serous carcinoma. To note, both the components were geographically separate from one another. Final diagnosis of uterine collision tumor was rendered, comprising of high grade endometrial stromal sarcoma and endometrioid adenocarcinoma FIGO grade I. The endometrial stromal sarcoma component was stage 1A, constituting approximately 80% of the tumor volume. The endometrioid adenocarcinoma component was also stage IA, constituting approximately 20% of the tumor volume. Regional lymph nodes and omental tissue were free of tumor infiltration. The case was discussed in our Multidisciplinary Tumor Board meeting and it was decided with consensus to keep the patient under close observation, in view of both the components being confined to Stage I and having undergone radical resection with R0 status. The patient is alive after 32 months of surgery when this report is being drafted.
Figure 1: (a) Contrast enhanced T1 fat-saturated MR image in sagittal plane showing polypoidal enhancing lesion in the fundal region (yellow arrow) and contiguous enhancement along the endometrial lining (red arrow). (b) Gross image of the specimen showing polypoidal fleshy mass (yellow arrow) and adjacent thickened endometrium (red arrow)

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Figure 2: (a) ESS component infiltrating into myometrial smooth muscle fibres (H and E, x40). (b) Sheets of atypical spindle cells (H and E, x200). (c) Atypical spindle cells with brisk mitotic activity (H and E, x400). (d) ESS component non-immunoreactive for ER (IHC, x40). (e) ESS component predominantly non-immunoreactive for CD10 with patchy weak staining (IHC, x20). (f) Focal patchy immunoreactivity for Cyclin D1 in the ESS component (IHC, x100)

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Figure 3: (a) EAC on the top left and ESS on the bottom right of the image (H and E, x40). (b) EAC invading superficially into the myometrium (H and E, x40). (c) Back to back arranged glands of EAC with mild nuclear atypia (H and E, x100). (d) EAC component highlighted with PanCK (IHC, x40). (e) EAC component immunoreactive for ER (IHC, x40). (f) EAC component non-immunoreactive for p53 (IHC, x100

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   Discussion Top

Collision tumors are characterized by the occurrence of two or more juxtaposed, histologically distinct tumor types at the same anatomic site. These are different from composite tumors which show intermingling of more than one tumor component. Carcinosarcoma of the uterus is a well-known example of uterine composite tumor, characterized by mixture of malignant epithelial and mesenchymal elements. However, it would be a misdiagnosis in our case as there is coexistence of two adjacent and histologically distinct tumors, endometrial stromal sarcoma and endometrioid adenocarcinoma, best categorized as a collision tumor.

Uterine collision tumors are rare with only few previously published case reports. [Table 1] illustrates the previous reports and compares the management and outcome with the present case. The review of previous literature suggests that collision tumor of endometrial adenocarcinoma and endometrial stromal sarcoma have a better prognosis than a similarly staged carcinosarcoma which behave aggressively. Management of carcinosarcoma needs multimodality approach including surgery, chemotherapy, radiotherapy and sometimes hormonal therapy. Whereas, management of collision tumors is determined by taking into consideration the grade and depth of invasion of the carcinomatous component, or characteristics of the endometrial stromal sarcoma. The literature suggests that adjunct surgery, such as lymphadenectomy, omentectomy and adjuvant chemoradiation, needed for carcinosarcoma can be avoided in the patients with collision tumors. The pre-operative diagnosis of collision tumors is not possible in most cases as it requires extensive gross sampling with histological and immunohistochemical analysis. However, postoperative management is definitely guided by the histopathological diagnosis, which can save the patient from the morbidity caused by an additional chemotherapy and radiotherapy in selected cases.
Table 1: Summary of diagnosis, management and outcome of present and previously reported cases of uterine collision tumor

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   Conclusion Top

This case report emphasizes the importance of an accurate pathologic diagnosis in patients of uterine mixed epithelial and mesenchymal neoplasms which would further guide the management and affect the prognosis to a significant extent. Extensive gross sampling and careful morphological examination with immunohistochemistry is necessary for the diagnosis of this rare entity and to prevent misdiagnosis. This is the first case in Indian literature to the best of our knowledge. More such cases need to be studied and reported to decide management and to predict the survival and outcome.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.

   References Top

Wells M, Oliva E, Palacios J, Prat J. Mixed epithelial and mesenchymal tumours. In: Kurman RJ, Carcangiu ML, Herrington CS, Young HS, editors. WHO Classification of Tumours of Female Reproductive Organs, 4th ed. Lyon: International Agency for Research on Cancer; 2014. p. 148-51.  Back to cited text no. 1
Reichert RA. Pathology of the uterine corpus. In: Jonathan W Pine Jr, editor. Diagnostic Gynecologic and Obstetric Pathology: An Atlas and Text, 1st ed. Philadelphia: Lippincott Williams & Wilkins; 2012. p. 264-86.  Back to cited text no. 2
Wada H, Enomoto T, Fujita M, Yoshino K, Nakashima R, Kurachi H, et al. Molecular evidence that most but not all carcinosarcomas of the uterus are combination tumors. Cancer Res 1997;57:5379-85.  Back to cited text no. 3
Lifschitz Mercer B, Czernobilsky B, Dgani R, Dallenbach Hellweg G, Moll R, Franke WW. Immunocytochemical study of an endometrial diffuse clear cell stromal sarcoma and other endometrial stromal sarcomas. Cancer 1987;59:1494-9.  Back to cited text no. 4
Sreenan JJ, Hart WR. Carcinosarcomas of the female genital tract. A pathologic study of 29 metastatic tumors: Further evidence for the dominant role of the epithelial component and the conversion theory of histogenesis. Am J Surg Pathol 1995;19:666-74.  Back to cited text no. 5
Lam KY, Khoo US, Cheung A. Collision of endometrioid carcinoma and stromal sarcoma of the uterus: A report of two cases. Int J Gynecol Pathol 1999;18:77-81.  Back to cited text no. 6
Kim G, Pham HQ, Ramzan A, Elishaev E, Mhawech Fauceglia P. Endometrioid adenocarcinoma associated with endometrial stromal sarcoma: A rare, often unrecognized collision tumor. Gynecol Oncol Rep 2015;13:8-12.  Back to cited text no. 7
Liu G, Zhang C, Ma Z, Zhang Q, Liu B. Endometrial stromal sarcoma with endometrioid adenocarcinoma of the uterus: A case report. Int J Clin Exp Pathol 2015;8:5242-6.  Back to cited text no. 8
Xiu XX, Wang HL, Yun-Yi L, Fan-Dou K, Jin-Ping H. Endometrial stromal sarcoma in combination with mixed type endometrial carcinomas: A case report and literature review. Medicine (Baltimore) 2017;96:e8928.  Back to cited text no. 9

Correspondence Address:
Shobhna Sharma
Department of Histopathology, Lab Medicine, Artemis Hospitals, Sector 51, Gurugram - 122 001, Haryana
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/IJPM.IJPM_701_20

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