Mixed high-grade serous and large cell neuroendocrine carcinoma arising from rectal endometriosis 11 years after hysterectomy.

The malignant gastrointestinal endometriosis transformation is represented by endometriosis-associated intestinal tumors. Endometrioid adenocarcinoma and clear cell adenocarcinoma are most common among the endometrial cancers of all organs. Only four cases of mixed serous carcinoma and large cell neuroendocrine carcinoma have been reported, and all these cases originated from the uterus. A 59-year-old woman with a month's history of bloody stools was admitted. She was stable until the hematochezia occurred but is 11 years post-hysterectomy. A circumferential type-3 advanced upper rectum tumor was seen on colonoscopy. Adenocarcinoma was revealed from the forceps biopsies of the type-3 tumor component. Computed tomography showed narrowed lumen with a thickened rectum wall, a continuing mass, and a component on the anorectal side. Swollen lymph nodes were observed around the rectum, but no distant metastatic lymph nodes or organs were found. To treat the lesion, rectal surgical resection with D3 lymph node dissection was performed. Histological examination revealed combined high-grade serous and large cell neuroendocrine carcinomas. Tumor was contiguous to the endometrium in the sub-serosa. Endometriosis was determined to be the origin of both carcinomas. Therefore, endometriosis-associated intestinal tumors should be included in the differential diagnosis when rectal tumors with cystic structures are found post-hysterectomy.

Laparoscopic posterior pelvic exenteration for clear cell adenocarcinoma arising in an episiotomy scar.

Malignant degeneration of endometriosis is a very rare event, especially when it develops in an episiotomy scar. A 53-year-old woman with an enlarged perineal mass presented to the hospital. She had undergone vaginal delivery with episiotomy twice. Imaging analyses showed a mass involving the levator ani muscle apart from the rectum, with lymph node metastases to the right inguinal and internal iliac regions. A biopsy specimen of the right inguinal lymph node revealed poorly differentiated adenocarcinoma. She underwent neoadjuvant chemotherapy according to the treatment strategy of anal fistula cancer. Laparoscopic posterior pelvic exenteration and pelvic lymph node dissection with anterior inguinal node dissection was performed, along with perineal reconstruction. Pathological examination revealed clear cell adenocarcinoma with lymph node metastases, derived from extrapelvic endometriosis in the episiotomy scar. She was treated with adjuvant chemotherapy according to the treatment strategy of vulvar cancer, and showed no evidence of recurrence after 15 months of surgery.

Tetraspanin 1 promotes endometriosis leading to ovarian clear cell carcinoma.

Ovarian clear cell carcinoma (OCCC) reportedly develops from endometriosis. However, the molecular mechanism underlying its malignant progression to OCCC remains elusive. This study aimed to identify an essential gene in the malignant transformation of endometriosis to OCCC. We performed RNA sequencing in formalin-fixed, paraffin-embedded (FFPE) tissues of endometriosis (n = 9), atypical endometriosis (AtyEm) (n = 18), adjacent endometriosis to OCCC (AdjEm) (n = 7), and OCCC (n = 17). We found that tetraspanin 1 (TSPAN1) mRNA level was significantly increased by 2.4- (DESeq2) and 3.4-fold (edgeR) in AtyEm and by 80.7- (DESeq2) and 101-fold (edgeR) in OCCC relative to endometriosis. We confirmed that TSPAN1 protein level was similarly overexpressed in OCCC tissues and cell lines. In immortalized endometriosis cell lines, TSPAN1 overexpression enhanced cell growth and invasion. Mechanistically, TSPAN1 triggered AMP-activated protein kinase (AMPK) activity, promoting endometriosis and cell growth. Upregulated levels of TSPAN1 are considered an early event in the development of high-risk endometriosis that could progress to ovarian cancer. Our study suggests the potential of TSPAN1 as a screening candidate for high-risk endometriosis.

Endometriosis-associated Clear Cell Carcinoma of the Abdominal Wall After Caesarean Section: A Case Report and Review of the Literature.

BACKGROUND/AIM: Clear cell carcinoma of the abdominal wall is a sporadic event. To date, about thirty cases have been reported in the literature. This article provides a case report and literature review of an infrequent occurrence with poor prognosis. CASE REPORT: A 45-year-old woman with pelvic pain and an abdominal mass came to our attention. Her medical history was notable for two previous cesarean sections. Physical examination revealed a smooth, multilocular mass measuring about 20 cm, arising from the previous surgical scar. Histology revealed clear-cell carcinoma resulting from the transformation of abdominal wall endometriosis. Given the disease extent, the patient underwent front-line chemotherapy. After several and multiple chemotherapy regimens, there was a disease progression that resulted in the death of the patient in 7 months. The literature review showed that a previous cesarean section was present in 91% of cases. Besides, approximately 26.5% of women died within 12 months of being diagnosed. The mean age of women was 45.88 years, while the average size of the lesion was 11 cm. CONCLUSION: Clear cell carcinoma is a rare but occurring event. Middle-aged women showing an abdominal wall mass in close relation with a surgical scar from a previous cesarean section must be promptly investigated. Treatment options usually include surgery and chemotherapy with poor results.

The Many Faces of Endometriosis-Related Neoplasms in the Same Patient: A Brief Report.

INTRODUCTION: Endometriosis is a common benign gynecological condition that can be associated with a slightly increased risk of developing a wide range of malignancies. CASE PRESENTATION: We herein report a singular case of a 62-year-old woman with a history of pelvic endometriosis, referred to our institution for chronic pelvic pain and uterine bleeding, with clinical and radiological evidence of left ovarian mass of 18 cm in largest diameter and multiple nodular mural lesions of the uterine cavity. The patient underwent exploratory laparotomy followed by hysterectomy, bilateral salpingo-oophorectomy, and omentectomy with pelvic lymph-node sampling. The histological examination of the ovarian mass revealed a clear-cell ovarian carcinoma arising from an endometriotic cyst. The microscopic examination of the uterine cavity showed multiple conventional leiomyomas, diffuse foci of adenomyosis, and a 1.5-cm yellow nodule diagnosed as low-grade endometrial stromal sarcoma associated with glandular atypical differentiation and with extension into parametrial and omental tissues. Following the diagnosis, the patient was treated with chemotherapy, radiation therapy, and hormonal therapy and after 9 months of follow-up is alive without local recurrences and distant metastases. DISCUSSION/CONCLUSIONS: To the best of our knowledge, the present case represents the first evidence of the simultaneous occurrence of clear-cell carcinoma and low-grade endometrial stromal sarcoma arising within ovarian and uterine endometriotic foci, respectively.

Endometriosis-associated epithelial ovarian cancer: Primary synchronous different cellular type on each ovary.

OBJECTIVE: Endometriosis-associated epithelial ovarian cancer (EOC) is a specific category of EOC, containing either endometrioid or clear cell carcinoma subtype. The characteristic of endometriosis-associated EOC includes an early stage at the diagnosis, presence of single histology type, and better prognosis. The synchronous two subtypes of endometriosis-associated EOC and presentation of far-advanced stage status at the initial diagnosis is rarely reported. CASE REPORT: We reported a 60-year-old postmenopausal woman with FIGO IA endometriosis-associated endometrioid carcinoma at right ovary and FIGO IVA endometriosis-associated clear cell carcinoma at left ovary, right tube, omentum, lymph node and cytology of pleural effusion and ascites treated with optimal debulking surgery and dose-intensity taxane/platinum based chemotherapy. CONCLUSION: This case report confirms the long-term concept that clear cell carcinoma has much more aggressive behavior than endometrioid cell carcinoma does, regardless of association of endometriosis or not.

Cancers associated with extraovarian endometriosis at less common/rare sites: A nationwide survey in Japan.

AIM: Endometriosis mostly affects the ovary but can also be present outside of the ovary including the pelvic peritoneum, intestine, urinary tract and lung. In case of ovarian endometriotic cyst, an increased risk of ovarian cancer, especially of clear cell and endometrioid histology, has been reported. However, because of the rarity, cancer occurrence from endometriosis at less common sites/rare sites is poorly understood. METHODS: We conducted a nationwide survey on the less common/rare site endometriosis in 3539 authorized facilities in Japan. We requested to complete a case report form for each case, including information on the history of endometriosis, treatment for endometriosis, type of surgery, involved site(s) of cancer and endometriosis, histology of cancer, chemotherapy and outcome. RESULTS: Out of 1397 confirmed cases of less common/rare site endometriosis, 11 cases of rare site endometriosis-associated cancer (RSEAC) were reported: seven of them were associated with intestinal endometriosis, three were associated with urinary tract endometriosis and one was associated with umbilical endometriosis. Interestingly, the histology was endometrioid in seven (64%) cases, and serous, seromucinous borderline, clear cell and mucinous in one case each (10%), differing from the case of ovarian endometriosis-associated cancer, in which clear cell carcinoma are more common. CONCLUSION: Our nationwide survey on RSEAC has revealed that: (i) the incidence of malignant transformation may be lower than ovarian endometriosis, (ii) malignant transformation from endometriosis outside the abdominal cavity may be extremely rare and (iii) the histology of RSEAC is predominantly endometrioid type, suggesting an association of a hormonal effect.

Comparison of clear cell carcinoma and benign endometriosis in episiotomy scar - two cases report and literature review.

BACKGROUND: Malignant endometriosis in an episiotomy scar is rare; only seven cases have been reported previously. Here, we compare two cases of benign endometriosis and clear cell carcinoma. CASE PRESENTATION: The first case was a 54-year-old woman who presented with a large perineal lesion in her episiotomy scar with high 18F-fluorodeoxyglucose uptake. This location had a history of endometriosis many years ago. She underwent radical excision of the mass and bilateral inguinal lymph node dissection. Histological and immunohistochemical analysis confirmed the presence of clear cell carcinoma arising from endometriosis. Assisted radiotherapy was performed after surgery due to a positive lymph node. No recurrence was detected over a 1-year follow-up period. The second case deals with a 3 × 2 cm mass in the episiotomy scar of a 33-year-old woman. Part of the anal sphincter was resected because of the close proximity of the lesion. Because the disease lay very close to the anus, she received anal sphincter reconstruction combined with mass excision. Pathology result showed typical endometrial glands and interstitial tissues. CONCLUSIONS: Deleterious change only happens in patients experiencing perineal endometriosis. Complete excision is crucial for this form of disease; sometimes impairment of the anal sphincter is also necessary. Patients with malignancy required a combination of treatments in order to improve their prognosis.

Clinical Characteristics of Clear Cell Ovarian Cancer: A Retrospective Multicenter Experience of 308 Patients in South Korea.

PURPOSE: The purpose of this study was to evaluate clinical characteristics and treatment pattern of ovarian clear cell carcinoma (OCCC) in Korea and the role of adjuvant chemotherapy in early stage. MATERIALS AND METHODS: Medical records of 308 cases of from 21 institutions were reviewed and data including age, performance status, endometriosis, thromboembolism, stage, cancer antigen 125, treatment, recurrence, and death were collected. RESULTS: Regarding stage of OCCC, it was stage I in 194 (63.6%), stage II in 34 (11.1%), stage III in 66 (21.6%), and stage IV in 11 (3.6%) patients. All patients underwent surgery. Optimal surgery (residual disease ≤ 1 cm) was achieved in 89.3%. Majority of patients (80.5%) received postoperative chemotherapy. The most common regimen was taxane-platinum combination (96%). Median relapse-free survival (RFS) was 138.5 months for stage I, 33.4 for stage II, 19.3 for stage III, and 9.7 for stage IV. Median overall survival (OS) were not reached, 112.4, 48.7, and 18.3 months for stage I, II, III, and IV, respectively. Early-stage (stage I), endometriosis, and optimal debulking were identified as favorable prognostic factors for RFS. Early-stage and optimal debulking were also favorable prognostic factors for OS. Majority of patients with early-stage received adjuvant chemotherapy. However, additional survival benefit was not found in terms of recurrence. CONCLUSION: Majority of patients had early-stage and received postoperative chemotherapy regardless of stage. Early-stage and optimal debulking were identified as favorable prognostic factors. In stage IA or IB, adding adjuvant chemotherapy did not show difference in survival. Further study focusing on OCCC is required.

Translational genomics of ovarian clear cell carcinoma.

Ovarian clear cell carcinomas (OCCC) are rare aggressive, chemo-resistant tumours comprising approximately 13% of all epithelial ovarian cancers, which have distinct clinical and molecular features, when compared to other gynaecological malignancies. At present, there are no specific licensed targeted therapies for OCCC, although a number of candidate targets have been identified. This review focuses on recent knowledge underpinning our understanding of the pathogenesis of OCCC including direct and synthetic-lethal therapeutic strategies in particular focussing on ARID1A deficiency. We also discuss current targeted clinical trials and immunotherapeutic approaches.

Anterior Pelvic Exenteration for Chemo-irradiated Non-diethylstilbestrol Exposed Clear Cell Vaginal Cancer.

BACKGROUND/AIM: Clear cell vaginal adeno-carcinomas are rare tumors occurring in women which are usually treated by chemo radiotherapy with good outcomes. However, in certain cases, this treatment is not associated with complete response and a further surgery is needed. CASE REPORT: We present the case of a 38-year-old patient diagnosed with stage IVA clear cell vaginal cancer who had been previously submitted to radio chemotherapy and in whom the lesion persisted after the oncological treatment; therefore, the patient was proposed for surgery with curative intent. The tumor was resected by performing an anterior pelvic exenteration with good outcomes, the patient being discharged in the seventh postoperative day. At one-year follow-up the patient remains free of recurrent disease. CONCLUSION: Pelvic exenteration with curative intent might be the option of choice for persistent locally advanced clear cell vaginal cancer.

Malignant transformation of vaginal adenosis to clear cell carcinoma without prenatal diethylstilbestrol exposure: a case report and literature review.

BACKGROUND: We report an extremely rare case of vaginal clear cell carcinoma, which originated from the malignant transformation of vaginal adenosis without prenatal diethylstilbestrol (DES) exposure. CASE PRESENTATION: In this case, the patient was a Chinese woman with a history of two decades of intermittent vaginal pain, sexual intercourse pain and vaginal contact bleeding. On September 1, 2011, when the patient was 39 years old, a vaginal biopsy revealed vaginal adenosis. After intermittent drug and laser treatment, her symptoms did not improve. Four years later, on March 4, 2015, another vaginal biopsy for abnormal vaginal cytology revealed atypical vaginal adenosis. After treatment with sirolimus, her symptoms and abnormal vaginal cytology results persisted, and she underwent laparoscopic hysterectomy with bilateral salpingo-oophorectomy and excision of the vaginal lesions. One year after the hysterectomy, on August 15, 2017, the vaginal cytology results suggested atypical glandular cells, and a biopsy revealed vaginal clear cell carcinoma originating from the atypical vaginal adenosis. A wide local resection of the vaginal lesions was performed, followed by concurrent chemoradiotherapy. Regular follow-up over 16 months showed no evidence of the recurrence of vaginal adenosis or cancer. CONCLUSIONS: Based on the evolution of a series of pathological evidence, we report the fourth case in the world of vaginal clear cell carcinoma originating from vaginal adenosis without prenatal DES exposure. Wide local excision with radiotherapy provided at least 16 months of disease-free survival.

Mixed endometrioid and clear cell carcinoma arising from laparoscopic trocar site endometriosis.

Laparoscopic port site endometriosis is less common in abdominal wall endometriosis, and malignant transformation of abdominal wall endometriosis is rare. We reported a case of mixed endometrioid and clear cell carcinoma arising from port site endometriosis. The patient was a 49-year-old woman with a history of laparoscopic excision of ovarian endometrioma. Physical examination revealed a subcutaneous solid tumor around the laparoscopic surgical scar. Imaging showed a suspicious malignancy. She underwent radical marginal resection of the abdominal wall tumor, flap reconstruction of the abdominal wall, hysterectomy, bilateral salpingo-oophorectomy and omental biopsy. Histological examination revealed mixed endometrioid and clear cell carcinoma. Computed tomography scan showed no evidence of recurrence after six cycles of chemotherapy. This is the first case of malignant transformation from laparoscopic trocar site endometriosis.

Primary Clear Cell Adenocarcinoma of the Vulva: A Case Study With Mutation Analysis and Literature Review.

Primary vulvar clear cell carcinoma (CCC) is extremely rare. In this article, we report a primary vulvar CCC along with immunohistochemical and gene mutation analyses results and literature review to discuss the clinicopathological features and tumorigenesis of this rare tumor. A 70-year-old (gravida 2 para 2) Japanese woman complained of bleeding from a vulvar mass at a past episiotomy site. A 1.8 × 1.8 × 0.5 cm exophytic sessile mass was present on the vestibular area inside the left labium minora. Radical local excision of the tumor and resection of the inguinal lymph nodes on both sides were performed. Histopathology revealed a vulvar CCC with immunohistochemical positivity for PAX8, HNF-1ß, ER, and CA125, and negativity for p16, CD10, GATA3, PTEN, and PAX2, suggesting its Müllerian origin. No lymph node metastasis was observed. The tumor was a 5-mm exophytic growth without deep stromal invasion; thus, it was difficult to measure the invasion depth assuming a squamous cell carcinoma. To investigate pathogenic/oncogenic mutations in 50 cancer-related genes, we used the AmpliSeq Cancer Hotspot Panel. However, no pathogenic/oncogenic mutations were detected. Literature review revealed that most cases of vulvar CCC are associated with vulvar endometriosis. In particular, cases with clinically evident endometriosis at the episiotomy scar should be carefully observed. Evidence-based pathological stages of vulvar adenocarcinoma including CCC remain to be established owing to its rarity, with nationwide or global accumulation of cases required in future.

Survival Following Chemotherapy in Ovarian Clear Cell Carcinoma Is Not Associated with Pathological Misclassification of Tumor Histotype.

PURPOSE: Although ovarian clear cell carcinomas (OCCC) are commonly resistant to platinum-based chemotherapy, good clinical outcomes are observed in a subset of patients. The explanation for this is unknown but may be due to misclassification of high-grade serous ovarian cancer (HGSOC) as OCCC or mixed histology. EXPERIMENTAL DESIGN: To discover potential biomarkers of survival benefit following platinum-based chemotherapy, we ascertained a cohort of 68 Japanese and Australian patients in whom progression-free survival (PFS) and overall survival (OS) could be assessed. We performed IHC reclassification of tumors, and targeted sequencing and immunohistochemistry of known driver genes. Exome sequencing was performed in 10 patients who had either unusually long survival (N = 5) or had a very short time to progression (N = 5). RESULTS: The majority of mixed OCCC (N = 6, 85.7%) and a small proportion of pure OCCC (N = 3, 4.9%) were reclassified as likely HGSOC. However, the PFS and OS of patients with misclassified samples were similar to that of patients with pathologically validated OCCC. Absent HNF1B expression was significantly correlated with longer PFS and OS (P = 0.0194 and 0.0395, respectively). Mutations in ARID1A, PIK3CA, PPP2R1A, and TP53 were frequent, but did not explain length of PFS and OS. An exploratory exome analysis of patients with favorable and unfavorable outcomes did not identify novel outcome-associated driver mutations. CONCLUSIONS: Survival benefit following chemotherapy in OCCC was not associated with pathological misclassification of tumor histotype. HNF1B loss may help identify the subset of patients with OCCC with a more favorable outcome.

Alterations in ß-catenin, microsatellite instability, and HNF-1ß levels are independently associated with ovarian endometriosis-associated tumorigenesis.

We focused on specific molecular events during the development of endometriosis-associated ovarian endometrioid carcinoma (OEmCa) and ovarian clear cell carcinoma (OCCCa). Alterations in ß-catenin (encoded by CTNNB1) and microsatellite instability (MSI), as well as changes in the expression levels of HNF-1ß and DNA mismatch repair (MMR) proteins were investigated in 50 OEmCas and 21 OCCCas with endometriotic lesions. Mutations of CTNNB1 were identified in 28 (56%) of the 50 OEmCa cases and 26 (41.9%) of the 62 coexisting endometriosis lesions. MSI-high (H) was observed in 7 (14.6%) of the 48 OEmCa and 14 (23.3%) of the 60 coexisting endometriosis, and was significantly associated with loss of MMR protein expression, but not CTNNB1 mutations. Nonidentical CTNNB1 status between 2 different epithelial lesions within endometriosis was observed in 8 of 10 informative endometriosis cases that had adjacent OEmCa. Similar findings for MSI features were also found in 2 of 3 informative cases, suggesting that endometriotic lesions may predominantly consist of polyclonal cells. In contrast, high HNF-1ß expression was significantly associated with SLC3A1 expression, which plays a major role in HNF-1ß-triggered induction of reactive oxygen species in OCCCas, independent of abnormalities in both ß-catenin and MSI/MMR status. Finally, 4 inflammatory parameters associated with repeated hemorrhaging in endometriosis were significantly higher in endometriosis with MSI-high when compared with that with MSS, independent of both ß-catenin and HNF-1ß status. In conclusion, different molecular pathways including alterations in ß-catenin, MSI, and HNF-1ß levels may contribute to tumorigenesis in endometriosis-associated carcinoma.

Clear Cell Carcinoma of the Abdominal Wall as a Rare Complication of General Obstetric and Gynecologic Surgeries: 15 Years of Experience at a Large Academic Institution.

The objective of this article was to report the clinicopathological characteristics, treatment modalities, and outcomes of patients with clear cell carcinoma (CCC) of the abdominal wall. Medical records of six patients diagnosed with CCC of the abdominal wall between May 2003 and May 2018 at the National Taiwan University Hospital were reviewed. All patients had prior obstetric or gynecologic surgeries. The primary clinical presentation was enlarging abdominal masses at previous surgical scars. Four patients underwent initial/primary surgeries with/without adjuvant chemotherapy. One patient received neoadjuvant chemotherapy followed by surgical intervention and adjuvant chemotherapy, the other received chemotherapy and sequential radiotherapy without any surgical intervention. Two of four patients undergoing initial/primary surgeries had disease recurrence and the remaining two cases without initial surgery experienced disease progression during primary treatment. Inguinal lymph nodes were the most frequent sites of recurrence. In conclusion, previous obstetric or gynecologic surgery can be a risk factor for CCC of the abdominal wall. Complete resection of abdominal wall tumor and suspected intra-abdominal lesions with hysterectomy and bilateral inguinal lymph nodes dissection may be the primary treatment. Adjuvant chemotherapy would be considered for potential benefits. For patients without bilateral inguinal lymph nodes dissection, careful inguinal lymph node palpation during postoperative surveillance is necessary. More cases are still needed to elucidate the clinical management of this disease.

Malignant transformation of abdominal wall endometriosis to clear cell carcinoma: case report

ABSTRACT BACKGROUND: Malignant transformation of endometriosis in the abdominal wall is a rare and still poorly understood event. Less than 30 cases have been reported in the worldwide literature. Most cases of solid tumors are report in a previous abdominal scar with malignant transformation of a focus of endometriosis. Presence of lymph node metastases in nearby chains is frequent and is associated with poor prognosis. CASE REPORT: We report a case of a 42-year-old woman with a history of abdominal surgery (Pfannenstiel) to resect abdominal wall endometriosis. Physical examination revealed a solid mass of approximately 10 cm x 6 cm in the anterior wall of the abdomen. Computed tomography (CT) of the abdomen and pelvis showed a heterogeneous, predominantly hypoattenuating expansive formation measuring 10.6 cm x 4.7 cm x 8.3 cm. The patient underwent exploratory incisional laparotomy, block resection of the abdominal mass and lymphadenectomy of the external and inguinal iliac chains. The abdominal wall was reconstructed using a semi-absorbable tissue-separating screen to reconstitute the defect caused by resection of the tumor. Histological evaluation revealed infiltration by malignant epithelioid neoplasia, thus confirming the immunohistochemical profile of adenocarcinoma with clear cell components. Lymphadenectomy showed metastatic involvement of an external iliac chain lymph node. CONCLUSION: Resection of the mass along with the abdominal wall, with wall margins, is the most effective treatment. Reconstruction is a challenge for surgeons. The patient has been followed up postoperatively for eight months, without any evidence of disease to date.

Long-term survival of a patient with malignant transformation of extragonadal endometriosis treated solely with chemotherapy: A case report.

A 52-year-old woman presented to our hospital complaining of genital bleeding and was found to have a 50-mm vaginal tumor that involved the bladder, rectum, and small bowel and extended to the left pelvic side wall. Her history included a bilateral salpingo-oophorectomy and a total abdominal hysterectomy for fibroids and endometriosis. She had been prescribed estrogen replacement therapy (1.25 mg/day) following the second surgery and continued it for 8 years. The pathology of the vaginal biopsy showed endometrioid adenocarcinoma. Total pelvic exenteration was recommended for complete resection, but she chose chemotherapy (paclitaxel 175 mg/m2 and carboplatin AUC:6). Clinical complete remission was obtained for 11 years. She had a recurrence 11 years later. She was again found to have a 5-cm vaginal tumor. Surgical excision with upper vaginectomy was performed. The tumor was resected without invasion of the bladder, rectum and small bowel. Histologic examination of the specimen confirmed clear cell carcinoma with endometriosis. Chemotherapy may be the first-line treatment that can preclude aggressive surgery for malignant transformation of extragonadal endometriosis. However, combined chemotherapy and surgery is necessary for this disease.