KRASmutation positive mucinous adenocarcinoma originating in mature ovarian teratoma: Case report and review of literature

Imaging features of mucinous carcinoma arising from mature teratoma showing cytokeratin 7+ and cytokeratin 20+ expression profile: A case report

Ovarian mature teratomas are benign, but malignant transformation can occur infrequently, especially in women of advanced age. The tissue that undergoes malignant change is mostly squamous cell carcinoma, although adenocarcinoma has been reported in a small number of cases. The immunostaining results of adenocarcinoma usually show a cytokeratin (CK)7-/CK20+ expression profile, corresponding to lower gastrointestinal tract origin. In this report, we describe a case of mucinous carcinoma arising from an ovarian mature teratoma showing a CK7+/CK20+ profile and discuss its imaging features. A 40-year-old woman presented to her primary care physician with abdominal distension and poor oral intake, and she was referred to our hospital. She had been diagnosed with an ovarian mature teratoma at our institution 3 years earlier. At the current presentation, pelvic magnetic resonance imaging showed a large multilocular cystic mass with adipose tissue extending into the upper abdomen. Densely packed cysts were observed inside the mass, which showed weak contrast enhancement on contrast-enhanced imaging and a mildly high signal on diffusion-weighted imaging. A portion of the cysts also showed abnormal 18F-fluorodeoxyglucose uptake (maximum standardized uptake value, 13.2) on positron emission tomography/computed tomography. The patient was subsequently diagnosed with mucinous carcinoma showing a CK7+/CK20+ profile arising from a mature teratoma by pathologic examination. This mucinous carcinoma arising from a mature teratoma showed a CK7+/CK20+ profile and took the form of densely packed multilocular cysts. In this respect, it was similar to primary ovarian epithelial mucinous carcinoma on both magnetic resonance imaging and pathologic examination despite showing a much higher maximum standardized uptake value than that of primary ovarian mucinous carcinoma. When a large ovarian teratoma contains a large multilocular cyst, the presence of densely packed multilocular cysts should not be missed even in a mass without solid components. Clinicians should consider the possibility of mucinous carcinoma showing a CK7+/CK20+ profile arising from a mature teratoma in such cases.

Colorectal Adenocarcinoma Derived From Mature Cystic Teratomas: A Case Report With Review of the Literature

Mature cystic teratomas (MCTs) are the most common benign ovarian germ cell neoplasms in women of reproductive age. Rarely, somatic malignancies arise from MCTs, the most common being squamous cell carcinoma. Adenocarcinomas are less common and colorectal adenocarcinomas are extremely rare. We present a case of somatic adenocarcinoma of colorectal type which may pose challenges in diagnosis and treatment. A middle-aged female presented to the Emergency Department with lower abdominal pain. CT scan revealed an 11 cm sharply demarcated left pelvic mass. Laparoscopy showed a left ovarian mass with torsion, a smooth external surface, and thick brownish contents. An intraoperative evaluation was consistent with an adenocarcinoma. Permanent histopathology revealed adenocarcinoma of colorectal phenotype with necrosis. Additional evaluation of the cyst showed benign colonic epithelial lining. The immunohistochemistry (IHC) profile of positive CDX2 and CK20 and negative PAX8, CK7, ER, and PR suggested a colorectal-type somatic adenocarcinoma arising from the MCT and was staged as IA, after negative endoscopic findings. Due to their rarity and atypical symptoms, distinguishing metastatic tumors from MCT-derived somatic malignancies is a challenging process. CT scan and serum tumor markers can be helpful but are not definite. Thorough clinical evaluation and proper staging are necessary after pathologic evaluation. Extensive sampling and IHC can further characterize the origin of the tumor. Diligent sampling and a high index of suspicion in this case clinched the correct diagnosis and clinical management. The patient is being treated for stage IA ovarian cancer as opposed to stage IV metastatic colorectal cancer.

Genomic profiling of a metastatic anaplastic melanocytic neuroectodermal tumor arising from a mature thymic teratoma as part of a mediastinal germ cell tumor

Following chemotherapy, a mediastinal germ cell tumor can lead to a mature teratoma that is composed of tissues derived from all three germ layers. Although teratoma is usually curable, in rare cases it can give rise to various somatic tumors and exceptionally it undergoes melanocytic neuroectodermal tumor (MNT) transformation, a process that is not well-described. We report a patient with a postchemotherapy thymic teratoma associated with an MNT component who, 10 years later, additionally presented a vertebral metastasis corresponding to an anaplastic MNT. Using exome sequencing of the mature teratoma, the MNT and its metastatic vertebral anaplastic MNT components, we identified 19 somatic mutations shared by at least two components. Six mutations were common to all three components, and three of them were located in the known cancer-related genes KRAS (p.E63K), TP53 (p.P222X), and POLQ (p.S447P). Gene set enrichment analysis revealed that the melanoma tumorigenesis pathway was enriched in mutated genes including the four major driver genes KRAS, TP53, ERBB4, and KDR, indicating that these genes may be involved in the development of the anaplastic MNT transformation of the teratoma. To our knowledge, this is the first molecular study realized on MNT. Understanding the clinicopathological and molecular characteristics of these tumors is essential to better understand their development and to improve therapeutics.

Adenocarcinoma of intestinal type arising in mature cystic teratoma of ovary: A diagnostic dilemma

Adenocarcinomas of intestinal type arising in mature cystic teratoma of ovary (MCT) are extremely rare and remain a diagnostic dilemma because of its similarities with MCT. Serum tumor markers CEA and SCC and also MRI may help in the preoperative diagnosis. Pathologist experience helps in intraoperative diagnosis.

Squamous cell carcinoma arising from mature cystic teratoma of the ovary: A challenging question for gynecologic oncologists

Mature cystic teratomas of the ovary have an incidence of 1.2-14.2 cases per 100.000 people per year. Malignant transformation occurs in approximately 2% of the cases, and usually consists of squamous cell carcinoma. The preoperative detection is difficult and the diagnostic accuracy of ultrasound, magnetic resonance imaging, and computed tomography is debated. The diagnosis is frequently made in the operating room or on final histological examination. Standard treatment consists of bilateral salpingo-oophorectomy, total hysterectomy and comprehensive surgical staging in early disease and optimal cytoreductive surgery in advanced disease. Paclitaxel/carboplatin- based chemotherapy is the most used adjuvant treatment, whereas more aggressive regimens can be adopted in patients with high tumor burden or recurrent disease. The efficacy of radiotherapy is still unproven. The prognosis is poor when the tumor has spread beyond the ovary. There are few information to provide commonly accepted guidelines for this malignancy.

Network analysis of microRNAs and genes in human osteosarcoma

To date, numerous studies have suggested that microRNAs (miRNAs) and genes play key roles in osteosarcoma (OS); however, the majority of these studies have been conducted with a specific focus on either the genes or the miRNAs, which has made the regulatory mechanisms of OS difficult to decipher. The aim of the present study was to systematically investigate the elements [genes, miRNAs and transcription factors (TFs)] associated with the morbidity of OS and to explore the associations among these elements, instead of focusing on one or several elements. The scattered data were collected from existing studies of OS, and three regulatory networks (abnormally expressed, related and global) were constructed to explore OS at a macroscopic level. The abnormally expressed network showed the numerous incorrect data linkages that are present when OS emerges, making it useful as a map of the faults in OS. In theory, the correction of these errors could lead to the prevention and even cure of the disease. Unlike studies in which cancer networks have been formed based purely on gene data, the present study focused on genes and miRNAs, as well as the associations among them, to form the regulatory networks of OS. The constructed regulatory networks were shown to contain numerous self-adaptation associations, which may aid in the analysis of the pathogenesis of OS. By comparing and analyzing the similarities and differences, a number of important pathways were highlighted. A notable finding was the predicted TFs obtained by the P-Match method, which could be used to further study the pathogenesis of OS. In the present study, the mechanism of OS has been systematically analyzed and a theoretical foundation for the mechanism has been provided, which may assist the development of gene therapy targeting OS.

KRAS mutation in adenocarcinoma of the gastrointestinal type arising from a mature cystic teratoma of the ovary

Mature cystic teratomas (MCT) in the ovary rarely undergo malignant transformation. Moreover, adenocarcinoma of the gastrointestinal type is much rarer. We present two cases of perimenopausal female pateints with mature cystic teratoma of single ovary, while local adenocarcinoma arising in the MCT. The malignancies showed immunohistochemical features of intestinal differentiation, such as strong positivity for CDX-2, villin and CK-20, and negativity for CK-7. Furthermore, the mutation analysis of molecular alteration revealed a KRAS gene mutation in the intestinal adenocarcinoma part, extending into benign intestinal-type epithelium linings. Yet the mutation was not present in the epidermal component of the teratoma. We present these as two unique cases of mucinous adenocarcinoma of the intestinal type arising from mature cystic teratoma. Moreover, we also submit that this KRAS mutation might contribute to identify malignant transformation of a MCT and suggest possible effect on targeted treatment decisions for anti-epidermal growth factor receptor (EGFR) therapy in metastasized patients.

Adenoma and carcinoma components in colonic tumors show discordance for KRAS mutation

Activating mutations in KRAS are common events in the pathogenesis of colorectal carcinoma and predict response to treatment with anti-EGFR antibodies. Molecular pathology testing for KRAS mutations has become the standard of practice for patients with metastatic colorectal carcinoma. Despite the known histologic and molecular differences between adenomas and carcinomas, the concordance of KRAS mutation between adenomas and carcinomas has not been established leaving some open questions regarding the appropriate choice of tissue for KRAS mutation analysis and correct interpretation of the test results. To address these questions, we analyzed the concordance of KRAS mutation in 70 tumors that contained both adenoma and carcinoma components (2 cases of intramucosal carcinoma, 66 cases with invasion of the submucosa, and 2 invading the muscularis propria). For each case, DNA was separately isolated from the adenoma and the carcinoma component and analyzed for KRAS mutation using direct sequencing. Overall, 30 (43%) of the adenoma cases and 36 (51%) of the carcinoma cases were positive for KRAS mutation. Of the 70 cases, 16 (23%) showed discordant results. Interestingly, the fraction of discordant cases went down as the depth of carcinoma invasion increased. In summary, we identified significant KRAS mutation discordance between the adenoma and carcinoma component of the lesion. Our results suggest that effort should be made to analyze only the invasive component of the lesion and that caution should be taken when interpreting a result based on DNA extracted from noninvasive elements.