World Journal of Clinical Cases

Low-grade appendiceal mucinous neoplasm: A case report

BACKGROUND Low-grade appendiceal mucinous neoplasms are papillary or flat mucinous tumors with low-grade cytologic atypia. They are the most frequent source of pseudomyxoma peritonei. They can be easily misdiagnosed, due to unspecific symptoms, with acute appendicitis, retroperitoneal tumors or adnexal mass. Cases of huge appendiceal mucinous neoplasms are even more extremely rare. CASE SUMMARY We report a 54-year-old patient who presented with a 10-month history of constant dull distension accompanied by nausea. A surgical procedure of total hysterectomy, bilateral adnexectomy, appendectomy, greater omentectomy and right hemicolectomy was performed as a result of the findings on ultrasound, computed tomography scan and magnetic resonance imaging. Diagnosis was made after the pathological examination, which revealed low-grade appendiceal mucinous neoplasm. The patient received hyperthermic intraperitoneal chemotherapy with cisplatin and was discharged from the hospital. CONCLUSION Low-grade appendiceal mucinous adenomas are rare tumors that are easily misdiagnosed, and a more thorough clinical workup is required to make a definitive diagnosis.

Primary ileal squamous cell carcinoma: A case report and review of literature

BACKGROUND Primary ileal squamous cell carcinoma (PISCC) is a rare malignant tumor of the ileum. Its development is an exceptional phenomenon, as the ileal mucosa is lined exclusively by simple columnar epithelium, with no native squamous epithelium under physiological conditions. PISCC accounts for fewer than 0.001% of all intestinal malignancies. As of 2025, only 12 confirmed cases have been documented in the global literature, predominantly as isolated case reports. CASE SUMMARY A 47-year-old female developed abdominal pain two years after chemotherapy for ovarian low-grade serous carcinoma (International Federation of Gynecology and Obstetrics stage IC1). Positron emission tomography/computed tomography showed localized thickening of the small intestinal wall in the right pelvic region with increased metabolic activity, suggesting implantation metastasis. The patient underwent partial ileal resection, intestinal anastomosis, appendectomy, omentectomy, and pericolic lymphadenectomy. Histopathological and immunohistochemical analyses confirmed a primary ileal low-grade squamous cell carcinoma. Postoperatively, the patient received intravenous doxorubicin plus carboplatin combined with anti-angiogenic targeted therapy. After six cycles, the regimen was changed to paclitaxel plus carboplatin with bevacizumab. Following five cycles, maintenance therapy with intravenous bevacizumab monotherapy was initiated, supplemented with adjunctive hepatoprotective agents. At the 30-month postoperative follow-up, the patient remained progression-free with no clinical or radiologic evidence of recurrence or distant metastasis. CONCLUSION Accurate diagnosis of PISCC requires integration of clinical history, systemic examination, histopathology, and immunohistochemical profiling to reduce misdiagnosis and missed diagnosis.

Ovarian-adnexal reporting and data system ultrasound evaluation and pathological characteristics of ovarian collision tumor

BACKGROUND Collision tumor are neoplasms, including two histologically distinct tumors that coexist in the same mass without histological admixture. The incidence of collision tumor is low and is rare clinically. AIM To investigate ultrasound images and application of ovarian-adnexal reporting and data system (O-RADS) to evaluate the risk and pathological characteristics of ovarian collision tumor. METHODS This study retrospectively analyzed 17 cases of ovarian collision tumor diagnosed pathologically from January 2020 to December 2023. All clinical features, ultrasound images and histopathological features were collected and analyzed. The O-RADS score was used for classification. The O-RADS score was determined by two senior doctors in the gynecological ultrasound group. Lesions with O-RADS score of 1-3 were classified as benign tumors, and lesions with O-RADS score of 4 or 5 were classified as malignant tumors. RESULTS There were 17 collision tumors detected in 16 of 6274 patients who underwent gynecological surgery. The average age of 17 women with ovarian collision tumor was 36.7 years (range 20-68 years), in whom, one occurred bilaterally and the rest occurred unilaterally. The average tumor diameter was 10 cm, of which three were 2-5 cm, 11 were 5-10 cm, and three were > 10 cm. Five (29.4%) tumors with O-RADS score 3 were endometriotic cysts with fibroma/serous cystadenoma, and unilocular or multilocular cysts contained a small number of parenchymal components. Eleven (64.7%) tumors had an O-RADS score of 4, including two in category 4A, six in category 4B, and three in category 4C; all of which were multilocular cystic tumors with solid components or multiple papillary components. One (5.9%) tumor had an O-RADS score of 5. This case was a solid mass, and a small amount of pelvic effusion was detected under ultrasound. The pathology was high-grade serous cystic cancer combined with cystic mature teratoma. There were nine (52.9%) tumors with elevated serum carbohydrate antigen (CA)125 and two (11.8%) with elevated serum CA19-9. Histological and pathological results showed that epithelial-cell-derived tumors combined with other tumors were the most common, which was different from previous results. CONCLUSION The ultrasound images of ovarian collision tumor have certain specificity, but diagnosis by preoperative ultrasound is difficult. The combination of epithelial and mesenchymal cell tumors is one of the most common types of ovarian collision tumor. The O-RADS score of ovarian collision tumor is mostly ≥ 4, which can sensitively detect malignant tumors.

Clinical analysis of 12 cases of ovarian neuroendocrine carcinoma

BACKGROUND Neuroendocrine neoplasms of the female genital tract are rare. AIM To enhance our clinical understanding of neuroendocrine carcinoma (NEC) of the ovary. METHODS A retrospective review was conducted on 12 patients diagnosed with NEC of the ovary, analyzing clinicopathological characteristics, treatment modalities, and survival status. RESULTS The median age at diagnosis was 34.5 years (range: 20 to 62 years). Among the 12 cases, 9 were small cell carcinoma of the ovary and 3 were large cell NEC. Five cases were stage I tumors, one case was stage IV, and six cases were stage III. Eleven patients underwent surgery as part of their treatment. All patients received adjuvant chemotherapy. Among the 12 patients, one patient received radiotherapy, and one patient with a BRCA2 mutation was administered PARP inhibitor maintenance after chemotherapy. The median progression-free survival was 13 months, and the median overall survival was 19.5 months. Four cases remained disease-free, while eight cases experienced tumor recurrence, including three cases that resulted in death due to disease recurrence. CONCLUSION NEC of the ovary is a rare condition that is more common in women of childbearing age and is associated with aggressive behavior and poor clinical outcomes. Surgical resection remains the mainstay of treatment, with some patients benefiting from adjuvant chemoradiation therapy.