Malignant transformation rate and p53, and p16 expression in teratomatous skin of ovarian mature cystic teratoma

Expression of p16 Tumor Suppressor Protein in Malignant Ovarian Germ Cell Tumors; Immunohistochemical Study

BACKGROUND

Malignant ovarian germ cell tumors represent small percentage of malignant ovarian neoplasms but they affect significantly young age group.

AIM OF THE STUDY

To investigate the immunohistochemical expression of p16 tumor suppressor protein in malignant ovarian germ cell tumors.

MATERIALS AND METHODS

Twenty-two malignant ovarian germ cell tumors (five dysgerminoma, eight immature teratoma, and nine yolk sac tumors), twenty mature cystic teratoma tumors and twenty normal ovarian tissue were immunohistochemically stained with p16 monoclonal antibody. Ki67 immunohistochemical staining was done for malignant ovarian germ cell tumors to assess proliferation.

RESULTS

We found that p16 tumor suppressor protein is overexpressed in all malignant ovarian germ cell tumors in both nuclear and cytoplasmic locations compared to control and to mature cystic teratoma (p-value <0.001). Cytoplasmic p16 expression was significantly correlated to Ki67 proliferation index in malignant ovarian germ cell tumors (p-value = 0.033, r = 0.445).

CONCLUSION

Overexpression of p16 in malignant ovarian germ cell tumors denotes that dysfunction of the cyclin dependent kinase pathway is involved in tumorigenesis of malignant ovarian germ cell tumors.

Clinical analysis of 12 cases of ovarian cystic mature teratoma with malignant transformation into squamous cell carcinoma

OBJECTIVE

This study aimed to examine the clinicopathological characteristics, treatment, and prognostic factors in 12 cases of malignant transformation of mature cystic teratoma of the ovary (MCTO).

METHODS

We performed a retrospective study of 12 patients with malignant transformation of MCTO who were admitted to the Affiliated Hospital of Qingdao University from 2003 to 2019. We examined case records, clinical parameters, and biological assessments.

RESULTS

The median age of the patients was 56.5 years and seven of them were postmenopausal. The average tumor size was 18.5 cm. All patients had pelvic masses at their first hospital visit. Nine of the patients had discomfort in the lower abdomen, two presented with a lower abdominal palpable mass, and three were complicated by fever. The median follow-up time was 73 months (12‒193 months). Ten patients survived with a disease-free status and two died.

CONCLUSIONS

There is a low incidence of malignant transformation of MCTO, and its most common histological type is squamous cell carcinoma. Age and tumor size are important factors in malignant transformation of teratomas. While there is a lack of treatment guidelines for malignant transformation of MCTO, early diagnosis and treatment may be beneficial for these patients.

Recurrence of ovarian squamous cell carcinoma with MET gene copy number variation: a case report and review of literature

Background

Malignant transformation such as ovarian squamous cell carcinoma (SCC) in ovarian mature cystic teratoma (OMCT) is a rare tumor. The gene mutation of ovarian SCC remains unclear. We herein report a recurrent case of ovarian squamous cell carcinoma with MET gene copy number variation.

Case presentation

A 60-year-old woman presented with recurrence of ovarian SCC 8 months after primary surgery. Adhesiolysis, right abdominal wall mass excision, prosthetics, enterectomy, enterostomy and partial cystectomy were performed by laparoscope. Pathologic examination demonstrated metastatic squamous cell carcinoma in ileocecus, rectum and abdominal wall muscle. MET gene copy number was elevated with copy number of six in this case. Postoperatively, the patient was treated with four cycles of combination chemotherapy with docetaxel and carboplatin. The patient was free of disease at 20 months’ follow-up.

Conclusions

Optimal cytoreductive surgery combined with platinum-based chemotherapy is recommended currently for not only primary tumor but also recurrence. For patients with malignant transformation in OMCT, prompt diagnosis and individualized treatment are crucial for better prognosis. Increased copy number of MET may be correlated with her poor PFS and can be a potential therapeutic target for this case.

The Driver Mutational Landscape of Ovarian Squamous Cell Carcinomas Arising in Mature Cystic Teratoma

Purpose: We sought to identify the genomic abnormalities in squamous cell carcinomas (SCC) arising in ovarian mature cystic teratoma (MCT), a rare gynecological malignancy of poor prognosis.Experimental design: We performed copy number, mutational state, and zygosity analysis of 151 genes in SCC arising in MCT (n = 25) using next-generation sequencing. The presence of high-/intermediate-risk HPV genotypes was assessed by quantitative PCR. Genomic events were correlated with clinical features and outcome.Results: MCT had a low mutation burden with a mean of only one mutation per case. Zygosity analyses of MCT indicated four separate patterns, suggesting that MCT can arise from errors at various stages of oogenesis. A total of 244 abnormalities were identified in 79 genes in MCT-associated SCC, and the overall mutational burden was high (mean 10.2 mutations per megabase). No SCC was positive for HPV. The most frequently altered genes in SCC were TP53 (20/25 cases, 80%), PIK3CA (13/25 cases, 52%), and CDKN2A (11/25 cases, 44%). Mutation in TP53 was associated with improved overall survival. In 8 of 20 cases with TP53 mutations, two or more variants were identified, which were bi-allelic.Conclusions: Ovarian SCC arising in MCT has a high mutational burden, with TP53 mutation the most common abnormality. The presence of TP53 mutation is a good prognostic factor. SCC arising in MCT share similar mutation profiles to other SCC. Given their rarity, they should be included in basket studies that recruit patients with SCC of other organs. Clin Cancer Res; 23(24); 7633-40. ©2017 AACR.