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.

Endometriosis, affecting 6%-10% of women of reproductive age, can lead to severe symptoms such as chronic pelvic pain and infertility. Among its rarer manifestations is abdominal wall endometriosis (AWE), which has been increasingly reported following cesarean deliveries. This case discusses a 39-year-old woman who presented with a 13-year history of cyclical pain at her cesarean section scar, exacerbated over the last year by the development of a painful abdominal mass. Medical evaluations indicated endometriosis at the scar, with further investigations including ultrasound and magnetic resonance imaging showing involvement of the rectus abdominis muscle. Elevated tumor markers HE4 and CA-125, along with a biopsy, confirmed adenocarcinoma. The patient underwent extensive surgical treatment, including the resection of the mass, hysterectomy, bilateral salpingo-oophorectomy, and lymphadenectomy. Pathology confirmed moderately differentiated infiltrative adenocarcinoma originating from endometriosis. Despite the absence of postoperative chemotherapy, the patient showed no recurrence, emphasizing the effectiveness of comprehensive surgical management. This case highlights the critical importance of recognizing the potential for malignant transformation in AWE, particularly following cesarean deliveries, and underscores the necessity for vigilant monitoring and personalized treatment strategies. The management of AWE, especially when malignant transformation is suspected, necessitates a multidisciplinary approach similar to that used in ovarian cancer, focusing on rigorous surgical intervention and the potential for adjuvant therapies.

Although adenomyosis is a benign uterine disease, it can turn malignant in rare instances. Cystic adenomyosis is a rare variation of adenomyosis, arising from which 8 cases of clear cell carcinoma have been reported. However, to the best of our knowledge, there have been no previous reports describing the mechanism by which clear cell carcinoma develops from cystic adenomyosis. The present report documents a case of a 73-year-old woman who was referred to Kanazawa University Hospital (Kanazawa, Japan) because of cystic adenomyosis, with a solid part inside the cyst. The patient was diagnosed with cystic adenomyosis at Shonan Obstetrics and Gynecology Hospital (Hakusan, Japan) 17 years prior; however, the size of the cyst increased after menopause. Therefore, malignant transformation was suspected, which warranted simple abdominal hysterectomy and bilateral salpingo-oophorectomy. The final diagnosis of the present case was uterine corpus cancer, clear cell carcinoma, stage IA. Immunohistochemical staining revealed that the normal and transitional atypical epithelial cells lining the cyst wall, in addition to the clear cell carcinoma cells (which were inside mural nodules located on the cyst wall), were positive for 8-hydroxy-20-deoxyguanosine. This observation suggested the presence of chronic oxidative stress around the cystic adenomyosis. Therefore, the present case suggests the possible involvement of chronic oxidative stress in the malignant transformation of cystic adenomyosis to clear cell carcinoma. This mechanism of malignant transformation of cystic adenomyosis appears to be similar to that of the malignant transformation of endometriotic cysts. Therefore, if the size of the cystic adenomyosis increases after menopause or if the solid part appears in the cyst in future cases, then the possibility of malignant transformation should be considered.

Clear cell carcinoma (CCC) of the diaphragm is rare, with an origin that is reported to be associated with malignant transformation of extraperitoneal endometriosis. Lynch syndrome (LS) is an autosomal dominant hereditary cancer syndrome caused by germline pathogenic variants in one of the DNA mismatch repair (MMR) genes, MLH1, MSH2, MSH6 and PMS2. Women with LS have a significantly increased lifetime risk of endometrial and ovarian cancer. CCC is a common histology of endometriosis- and LS-associated malignancy. The present study describes the case of a 51-year-old woman with an intra-abdominal mass found during a routine physical examination. The patient had undergone total hysterectomy and bilateral adnexectomy for atypical endometrial hyperplasia (AEH) and ovarian endometriosis, respectively, 3 years previously. Enhanced computed tomography showed a mass on the surface of the liver. Laparoscopic examination of the abdominal cavity revealed a tumor on the underside of the right diaphragm, which was then surgically excised. Pathological examination of the excised tumor, along with immunohistochemistry, led to a diagnosis of CCC. Since LS was suspected due to the genetic family history of the patient, microsatellite instability analysis was performed on the diaphragmatic tumor, and the results were positive. Immunohistochemistry was performed for MMR proteins in AEH and CCC cells, both of which revealed loss of MSH2 and MSH6 expression. Following detailed genetic counseling, genetic testing of MMR genes was performed, revealing a germline pathogenic variant in MSH2 (c.1000C>T, p.Gln344*), thus confirming the diagnosis of LS. To the best of our knowledge, this is the first case report of concurrent diaphragmatic CCC and LS. Patients with LS and endometriosis are at risk of developing ovarian cancer or intra-abdominal malignant tumors. In addition, immunohistochemistry screening for MMR proteins should be considered in patients with AEH and a family history of LS-related cancer, to enable early clinical intervention in cases of endometrial cancer.

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UNASSIGNED: Malignant transformation in dermoid cysts is rare, and Squamous Cell Carcinoma (SCC) is the most common form. This event often occurs in large tumors and middle-aged women.
UNASSIGNED: In this study, two cases are presented. They were menopause, and abdominal pain and adnexal mass was a common manifestation in both. Case 1 with adenocarcinoma arising in mature cystic teratoma had abnormal tumor markers and was diagnosed with a frozen section during surgery, but case 2 with SCC transformation had normal tumor markers, and the frozen section was not helpful in the first surgery. Both underwent complete staging surgery, and due to stage IC1 in case 1, she received chemotherapy, and in case 2, no adjuvant treatment was needed because of stage IA.
UNASSIGNED: Considering the rarity of malignant transformation in the dermoid cyst, the best surgical approach and adjuvant therapy indications need further research.

BACKGROUND: White Sponge Nevus (WSN) is traditionally considered a benign genetic disorder affecting the oral mucosa, primarily caused by pathogenic mutations in keratin 4 (KRT4) or keratin 13 (KRT13). Despite its benign nature, recent evidence has begun to question the malignant potential of WSN.
METHODS: We report a case involving a 70-year-old man who presented with a white lesion on the right floor of his mouth. Initial diagnostic evaluations confirmed the lesion as WSN. Over a one-year follow-up, the lesion underwent malignant transformation, evolving into local epithelial moderate-to-severe dysplasia. Exome sequencing identified a novel insertion mutation in exon 1 of the KRT4 gene, resulting in a deletion-insertion amino acid mutation involving glycine. Single-cell RNA sequencing further revealed altered epithelial proliferation and differentiation dynamics within the lesion.
CONCLUSIONS: This case not only expands the known genetic spectrum of KRT4 mutations associated with WSN but also provides preliminary evidence suggesting the malignant potential of WSN. The novel pathogenic mutation in KRT4 is postulated to alter epithelial proliferation and differentiation, thereby raising concerns about the malignant transformation of WSN. Further studies are warranted to confirm these findings.

Giant condyloma acuminata (GCA) is a rare, locally aggressive manifestation of human papillomavirus (HPV) infection, typically affecting the anorectal area. Patients with GCA often have a poor prognosis due to the high risk of malignant transformation. In this case report, we present a 39-year-old man with HIV who developed progressive and refractory anorectal GCA. Despite initially non-cancerous pathology results, there were concerns regarding a malignant component to the mass. Multidisciplinary discussions led to the decision to pursue definitive radiation therapy. This case report and review of the literature highlight the role of radiation in the management of GCA and the importance of a multidisciplinary approach in the treatment of complex cases.

UNASSIGNED: Since 1964, there has been a scarcity of reported cases of primary ameloblastoma (AM) or ameloblastic carcinoma (AMCa) of the skull. The clinical presentation and distinctive features of this uncommon condition at specific anatomical sites remain unclear. We report a case of malignant transformation of a primary AM of the skull situated in the frontal-temporal-parietal region and highlight its similarities to other cases reported in the literature.
UNASSIGNED: A 53-year-old female patient presented with a 20-day history of headaches and bilateral lower limb weakness for 10 days. Physical examination revealed slow and unsteady gait. An occupying lesion was observed in the right frontal-temporal-parietal region of the skull on the Cranial imaging. A right cranial bone tumor margin expansion resection was performed. The patient\'s motor functions recovered normally after surgery. Postoperative imaging examinations showed10 tumor resection. Follow-up imaging examinations showed tumor recurrence. The patient underwent resection of the recurrent tumor. Postoperative pathological analysis revealed malignant transformation of the AM.Follow-up imaging examinations showed tumor recurrence again. The patient was admitted for stereotactic radiotherapy. Follow-up imaging examinations demonstrated no evidence of tumor recurrence and subsequent chest CT revealed no signs of metastasis.
UNASSIGNED: Primary AM or AMCa of the skull is increasingly being described in the literature, but detailed reports on the malignant transformation of primary AM of the skull are lacking. The pathogenesis of this condition remains unclear. Aggressive treatment and close follow-up may be crucial for preventing disease recurrence and malignant transformation.

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.