Mucinous cystadenocarcinoma with sarcoma-like mural nodules arising in a mature cystic teratoma of the ovary: a case report

Malignant transformation of mature cystic teratoma of the ovary

Mature cystic teratoma is the most common ovarian germ cell neoplasm. Malignant transformation is a rare occurrence, accounting for 1.5%-2% of cases. Malignant changes can arise from any constituent tissue of a teratoma; however, squamous cell carcinoma is the most common histologic type seen, followed by adenocarcinoma and sarcoma respectively. Tumor marker concentration levels, age, and the tumor maximum diameter are predictive indicators for malignant transformation. Proper diagnosis includes recognizing the possibility of malignant transformation versus excluding other differential options, such as metastasis. Primary cytoreductive surgery, adjuvant chemotherapy, and radiotherapy are the current treatment methods. The aim of the review is to discuss the clinical and pathologic features of malignant transformation within mature cystic teratomas, while reviewing the reported malignant types, differential diagnoses, and treatment options. Data sources include review of pertinent peer-reviewed literature on malignant transformation of mature cystic teratoma and cases seen in authors' institutional practice. Mature cystic teratomas are a commonly encountered benign ovarian tumor. However, the possibility of malignant transformation should remain in consideration, especially with given clinical or pathologic features: increased patient age, tumor size, or tumor marker levels. Thorough sampling of solid tumor foci can help identify malignant components. Awareness and proper diagnosis, along with early detection and clinical management, shows improved patient outcomes.

Malign mural nodules associated with serous ovarian tumor of borderline malignancy: a case report and literature review

BACKGROUND

Cystic tumors of ovary, whether benign, borderline, or malignant may be associated with mural nodule of various types, including sarcomas, sarcoma-like mural nodules (SLMN), and foci of anaplastic carcinoma. Cases of serous borderline ovarian tumor with mural nodules of mixed type are very rare.

CASE

A 54-year-old woman referred with abdominal swelling. Imaging studies revealed a huge mass localized in pelvis and lower abdomen and grade 1-2 left renal hydronephrosis. Preoperative Ca-125 was 798 U/ml. In exploratory laparotomy there was a 16 cm mass adherent to lateral abdominal wall and intestines. Adhesiolysis and de-bulking surgery were performed including bilateral pelvic, para-aortic lymphadenectomy, appendectomy and omentectomy. Left ureter was found to be dilated because of the infiltration of distal part by the tumor, so distal ureteral resection and neoureterocystostomy were performed. Final pathology revealed borderline serous ovarian tumor with mural nodules which were consisted of SLMNs, multiple and sharply demarcated from the adjacent tumor, and sarcomatous nodules showing infiltrative appearance in metastatic regions. Mural nodules showed a positive reaction for vimentin and SMA but were negative for cytokeratin and also necrosis, hemorrhage, and 10-15 mitoses in 10 high power fields were noted. She had postoperative chemotherapy and follow-up is going on without metastases in her first year.

CONCLUSION

The existence of sarcomatous nodules combined with the SLMN necessitates a careful histologic analysis for treatment and the determination of prognosis. However, too few cases of mixed type mural nodules have been published to warrant a conclusion regarding their prognosis.

Ovarian Mucinous Tumors Associated With Mature Cystic Teratomas

Most primary ovarian mucinous tumors are of surface epithelial-stromal origin and exhibit diffuse expression of cytokeratin 7 (CK7) combined with variable expression of cytokeratin 20 (CK20); this immunoprofile distinguishes them from most lower gastrointestinal tract tumors secondarily involving the ovaries. The uncommon ovarian mucinous tumors of germ cell (teratomatous) origin have not been extensively evaluated to determine the utility of these markers and other markers of intestinal differentiation for distinguishing these tumors from metastatic gastrointestinal tract mucinous tumors. Immunohistochemical expression of CK7, CK20, CDX2, and villin was assessed in 44 ovarian mucinous tumors associated with a mature cystic teratoma. All cases lacked evidence of a nonovarian primary mucinous tumor. All mucinous tumors were unilateral; 6 cases had bilateral teratomas. All tumors displayed gastrointestinal-type mucinous differentiation, with epithelium that was commonly goblet cell-rich or hypermucinous; 21 were associated with pseudomyxoma ovarii and 3 of these had pseudomyxoma peritonei. Tumor architecture ranged from purely cystadenomatous (n=24), to proliferative (n=13), to carcinomatous (n=6); some tumors had admixtures of these patterns. One tumor had a goblet cell carcinoidlike pattern with pseudomyxoma ovarii. Three carcinomas had a signet ring cell component. Cystadenomatous tumors without pseudomyxoma ovarii (n=15) exhibited all possible CK7/CK20 coordinate expression profiles with nearly equal frequency. All proliferative tumors without pseudomyxoma ovarii (n=8) expressed CK7, most often in combination with CK20 expression. All cystadenomatous and proliferative tumors with pseudomyxoma ovarii (n=9 and n=5) were CK7-/CK20+. All carcinomatous tumors had pseudomyxoma ovarii; 3 were CK7-/CK20+, 2 were CK7+/CK20+, and 1 was CK7+/CK20-. The presence of pseudomyxoma ovarii was significantly associated with a CK7-/CK20+ profile (86% with pseudomyxoma ovarii vs. 13% without, P<0.0001), CDX2 positivity (79% vs. 0%, P<0.0001), and villin positivity (57% vs. 5%, P=0.0009). A subset of mucinous tumors associated with mature cystic teratomas exhibiting morphologic and immunohistochemical features of lower intestinal tract-type mucinous tumors may be teratomatous in origin. In practice, the more common diagnosis of secondary involvement by a lower intestinal tract mucinous tumor should be addressed in the pathology report and in subsequent clinical evaluation; interpretation as a true primary ovarian mucinous tumor of teratomatous origin can be considered as an alternative diagnosis when evaluation and follow-up fail to identify a nonovarian source of the mucinous tumor. Those tumors having CK7 expression with or without CK20 expression may be derived from upper gastrointestinal tract-type or sinonasal-type teratomatous elements but could be independent tumors of surface epithelial-stromal origin.

Mucinous adenocarcinoma arising from one retroperitoneal mature cystic teratoma in a postmenopausal woman*

Malignant degeneration of a retroperitoneal mature cystic teratoma to adenocarcinoma at postmenopausal age is extremely rare. A 72-year-old woman with mucinous adenocarcinoma arising from a retroperitoneal mature cystic teratoma is presented.

Mucinous adenocarcinoma and strumal carcinoid tumor arising in one mature cystic teratoma of the ovary with synchronous cervical cancer

Malignant transformation of mature cystic teratoma is an uncommon complication. While any of the constituent tissues of a teratoma has the potential to undergo malignant transformation, squamous cell carcinoma is the most commonly associated cancer. We present an unusual case of a postmenopausal woman with synchronous mucinous adenocarcinoma and strumal carcinoid tumor from one of two ovarian mature cystic teratomas (one in each ovary) with synchronous cervical cancer. We suggest that malignant transformation of mature cystic teratoma and synchronous cervical cancer be treated by hysterectomy, chemotherapy, and radiotherapy.

Sarcoma-like mural nodules in mucinous cystic tumors of the ovary revisited: a clinicopathologic analysis of 10 additional cases

Ten mucinous cystic ovarian tumors that contained sarcoma-like mural nodules are described. The nodules were studied by conventional and immunohistochemical methods. The sarcoma-like mural nodules occurred predominantly in middle-aged women, were multiple and sharply demarcated from the adjacent mucinous tumor, had small size, and exhibited a heterogeneous cell population. Distinction of these lesions from true sarcomatous nodules and foci of anaplastic carcinoma is important because of the worse prognosis of the two latter tumors compared with the favorable behavior of the sarcoma-like mural nodules. Six of the eight patients with follow-up information were alive and clinically free of recurrence at a mean follow-up interval of 12 years. Two patients died of other causes (thyroid and breast carcinomas). The nature of the nodules is not clear. Sarcoma-like mural nodules probably represent a reactive and self-limited phenomenon within a neoplasia. Their coexpression of vimentin and cytokeratins is consistent with an origin from submesothelial mesenchymal cells, which undergo partial transformation into epithelial cells.