Malignant transformation (MCT) of ovary is rare complications affecting elderly, squamous cell carcinoma being the most common. The prognosis worsens with extraovarian spread. We present two cases of MCT-derived SCC. Patients exhibited abdominal lump, pain, bowel symptoms, sometimes with weight loss; imaging revealed MCT. Age (51-60), postmenopausal status, large size (>20 cm), bilaterality, and complex ovarian lesions raised suspicion of malignancy. Elevated tumor markers (e.g., cancer antigen-125 and lactate dehydrogenase) were noted in one case. Intraoperative frozen section confirmed malignancy, guiding staging laparotomy. One case was advanced stage on histopathology. Intraoperative frozen section aids optimal staging.

The malignant transformation of mature cystic teratomas during pregnancy is a rare occurrence in medical literature. In this case report, we present a remarkable instance of mucinous intestinal adenocarcinoma arising from a mature ovarian cystic teratoma diagnosed during pregnancy. This is among the few reports detailing the effective use of the FOLFOX 6 chemotherapy regimen for treating this type of intestinal cancer. Furthermore, we emphasize the immunohistochemical results that confirm the colorectal histological origin.

BACKGROUND: Mature cystic teratomas (MCT) of the ovary are benign ovarian germ cell neoplasms. Malignant transformation is possible but rare and ovarian carcinoid tumors in MCT are among the most extremely rare subtypes.
METHODS: We report a case of a 60-year-old Iranian woman suffering from postmenopausal bleeding and hypogastric pain for the last 40 days. An adnexal mass was detected during the physical examination. Ultrasound imaging showed a (55 × 58) mm mass in the left ovary. Total abdominal hysterectomy, bilateral salpingooophorectomy and comprehensive staging surgery were performed for the patient. Intraoperative frozen section of the left ovarian mass was indicative of a malignant tumor. She was diagnosed with a carcinoid tumor with benign mucinous cystadenoma arising on MCT of the ovary, confirmed in the histopathology and immunohistochemistry examination. The tumor was classified as low grade and no chemotherapy cycles were considered. The patient was followed up long-term and no recurrence was observed during 14 months of examinations.
CONCLUSIONS: Ovarian carcinoids arising from MCT are rare neuroendocrine neoplasms, and proper diagnosis of these tumors requires careful histopathology evaluation and appropriate examination. Therefore, it is necessary to consider these tumors as a possible differential diagnosis and evaluate them in individuals (especially postmenopausal women) who have abdominal pain or abnormal bleeding and a palpable mass.

Ovarian mature cystic teratomas comprise tissue derived from all three germ layers and constitute 10-20% of all ovarian neoplasms. Malignant transformation of mature cystic teratomas (MCT) is very rare with an incidence of 0.17-2%. The most frequently reported malignancies include squamous cell carcinoma and adenocarcinoma. Herein, we describe a case of a 56-year-old female who presented with abdominal pain and underwent total abdominal hysterectomy with bilateral oophorectomy and omentectomy for a ruptured dermoid cyst. Histological examination showed nests of pleomorphic cells with prominent nucleoli and melanin pigment in the background of a mature cystic teratoma. These cells showed immunoreactivity for Melan-A and HMB-45, thus confirming the diagnosis of malignant transformation of a mature cystic teratoma to a malignant melanoma.

BACKGROUND: Mature cystic teratomas or dermoid cysts of the pancreas complicate surgical approaches because of their anatomical position and ever-growing size. Herein, we report a case of a giant mature cystic teratoma of the pancreas that was successfully resected via complete laparoscopic distal pancreatectomy (LDP).
METHODS: A 39-year-old female patient was referred to our hospital for the evaluation of a pancreatic tumor. Three years of follow-up revealed that the tumor had increased in size to 18 cm, with hyperintense solid components on diffusion-weighted magnetic resonance imaging. Considering the possibility of malignancy, we decided to perform an LDP. The capsule appeared solid enough to withstand the retraction of the endoscopic forceps. Tumor size made it difficult to dissect the dorsal side of the tumor from the caudal to the cranial side. Early transection of the pancreas and additional ports facilitated dissection of the dorsal side of the tumor. We completed the LDP without intraoperative cyst rupture. On pathological examination, the tumor was diagnosed as a mature cystic teratoma originating from the pancreatic tail. The patient was discharged on postoperative day 13 with no complications.
CONCLUSIONS: LDP may be an option for surgical procedures in patients with large cystic lesions of the pancreatic body or tail. Intraoperative observation of the tumor and surgical refinement are necessary to complete the laparoscopic procedure without tumor rupture.

BACKGROUND: Colorectal cancer (CRC) is one of the most common cancers worldwide, and screening colonoscopy has led to a decreasing incidence rate. However, the incidence of CRC is increasing among young people, especially adolescents and young adults (AYAs) who are not routinely screened. Although CRC is the fourth most common cancer among AYAs, it is extremely rare. In younger patients, CRC is often diagnosed later, and the proportion of patients with advanced CRC is higher than that in older patients. We herein present a case of poorly differentiated mucinous carcinoma of the ascending colon complicated by bilateral ovarian mature cystic teratomas (MCTs) in an AYA.
METHODS: A 17-year-old female patient presented with a chief complaint of abdominal pain and diarrhea that had persisted for more than 3 years. Colonoscopy revealed circumferential wall thickening of the ascending colon, and colonic biopsy revealed a mucous mass and findings of adenocarcinoma, predominantly signet ring cell carcinoma. Abdominal computed tomography (CT) and pelvic magnetic resonance imaging (MRI) showed bilateral ovarian tumors. Laparoscopic right hemicolectomy and enucleation of bilateral ovarian tumors were performed. Although the ascending colon cancer formed a large mass, there were no signs of peritoneal dissemination or direct invasion to the surrounding organs. Microscopically, the ascending colon was a poorly differentiated mucinous carcinoma with signet ring cell carcinoma and lymph node metastasis (9/42). The ovarian tumors were diagnosed as MCTs without any malignant components. The pathological diagnosis was ascending colon cancer (pT4aN2bM0, pStage IIIC) and bilateral ovarian MCTs. Microsatellite instability (MSI) testing was negative, and there were no gene mutations in either RAS or BRAF. Postoperative adjuvant chemotherapy with oxaliplatin and 5-FU was started.
CONCLUSIONS: We presented a case of locally advanced ascending colon cancer in a 17-year-old female patient. CRC rarely occurs in AYAs. However, the incidence has gradually increased in recent years. It should be considered as a differential diagnosis for young patients with long-term abdominal symptoms of unknown cause.

Mature cystic teratoma of the fallopian tube is extremely rare, with fewer than 100 cases reported in the English literature. Clinical symptoms are nonspecific, and the diagnosis is most often made after surgical resection. A preoperative diagnosis has the potential to aid with surgical planning and patient counseling. We present a case of a large completely intratubal mature cystic teratoma in a 40-year-old woman who presented to her primary care provider with the gradual onset of right lower quadrant/pelvic pain. The patient\'s symptoms prompted evaluation with computed tomography (CT) and ultrasound. Imaging showed a dilated right fallopian tube containing fluid, macroscopic fat, and calcifications, facilitating the preoperative diagnosis of mature cystic teratoma of the fallopian tube. Because of her symptoms, she elected to undergo salpingectomy and the diagnosis was pathologically confirmed. The patient\'s symptoms resolved following surgery.

BACKGROUND: Mature cystic teratoma of the ovary is classified among the benign ovarian germ cell neoplasms, and its malignant transformation occurs very rarely (in about 2%). As a result of nonspecific signs and symptoms, preoperative diagnosis of theses malignancies is a challenge to clinicians, resulting in delayed diagnosis (in advanced stages) and poor outcomes.
METHODS: We report the case of a 43-year-old Iranian woman with progressive distension of the abdomen and hypogastric pain, who was diagnosed with squamous cell carcinoma transformation in a mature cystic teratoma of the ovary confirmed by histopathology examination. Total abdominal hysterectomy, bilateral salpingooophorectomy, and comprehensive staging surgery were performed for the patient, and she was scheduled for chemotherapy after the surgery. She responded well to the treatment and is currently continuing her chemotherapy process.
CONCLUSIONS: There are a great number of reports in the literature regarding mature cystic teratoma of the ovary transformation into malignancy, so these neoplasms must be considered as a possible differential diagnosis and should be evaluated in older individuals with abdominal pain and palpable mass, or those with considerable tumor diameter and raised serum tumor markers.

Non-seminomatous germ cell tumors with structural components from all three cellular lineages are called teratomas. We report a rare case of a primary right adrenal teratoma in a postmenopausal female, presenting with abdominal pain. Ultrasound revealed a complex cystic shadow in the perihepatic region superior to the upper pole of the right kidney, which was suggestive of a complex supra-renal space-sequence-occupying lesion. Computerized tomography revealed a large-sized mature single multilobulated complex cystic lesion in the right hypochondrial lumbar region arising from the right adrenal gland. A right-sided transperitoneal adrenalectomy was performed. The resected mass (18 × 13 × 10 cm) was well encapsulated. Cut surfaces showed cystic mass filled with necrotic gray-white pultaceous material, along with a solid white gelatinous area. Microscopic sections showed a tumor which displayed differentiation along various tissue lineages. After immunohistochemical examinations, the tumor was confirmed to be a mature cystic teratoma. Mature teratomas show a good prognosis, and surgical resection and follow-up remain the standard approach.

UNASSIGNED: Mature cystic teratoma (MCT) is a common type of ovarian tumors that can, in rare cases, undergo malignant transformation. It has been discovered that MCT patients may experience psychiatric symptoms due to the presence of anti-N-methyl-D-aspartate receptor (NMDAR) antibodies, which is the underlying cause of autoimmune encephalitis. Here, we present the first documented case of a patient with anti-NMDAR encephalitis who also had a morphology of low-grade glioma within MCT.
UNASSIGNED: A 45-year-old woman presented with seizures, altered consciousness, abnormal NMDAR antibody IgG titers, and abnormal brain MRI findings confirm the diagnosis of anti-NMDAR encephalitis. Physical examination revealed an oval mixed echo mass measuring 54 × 37 mm in the left adnexal area on ultrasound of the uterine appendage. The patient underwent laparoscopic left ovarian and fallopian tube resection. The pathological gross examination revealed a pile of grayish-red cystic and solid fragmented tissue measuring 7 × 6 × 2.2 cm. Histological examination revealed characteristic components of MCT. Furthermore, the solid component of the gross tissue showed proliferative and densely arranged astrocytes with cellular atypia, which were positive for GFAP and Olig-2, negative for IDH1 and EMA. And the Ki67 index was approximately 10%, suggesting the presence of low-grade glioma lesions. The patient was diagnosed with malignant transformation of MCT into a morphology of low-grade glioma, not otherwise specified. After the removal of the ovarian tumor, the patient\'s psychiatric symptoms improved.
UNASSIGNED: Low-grade glioma within MCT is a rare occurrence, and the presence of this malignant transformation in patients with anti-NMDAR encephalitis is even more uncommon.