International Cancer Conference Journal最新文献

Mature cystic teratomas are common benign ovarian neoplasms, but rupture is a rare complication, occurring in less than 5% of cases. Peritonitis with granulomatous lesions following rupture, mimicking peritoneal carcinomatosis, is extremely rare and is not typically reported as a complication. We report the case of a 48-year-old Caucasian female with lower abdominal pain and suspected four-quadrant peritonitis. A 7.9 cm teratoma was identified on CT scan. Exploratory laparoscopy revealed numerous adhesions and fibrinous exudate. Initially, cytoreductive surgery and hyperthermic intraperitoneal chemotherapy were recommended due to a highly suspected malignancy, initially thought to be pseudomyxoma peritonei. However, laparotomy revealed over 50 encapsulated mucoid micronodular lesions and pronounced adhesions throughout the entire abdominal cavity. Despite the macroscopic appearance, no evidence of malignancy was found in any of the numerous frozen sections sent for analysis. Histopathology confirmed a mature cystic teratoma with multifocal foreign body granulomas. No malignancy was detected. It is likely that multiple (silent) ruptures of the mature cystic teratoma were responsible for this unusually pronounced inflammatory response in the whole abdomen. This case report presents a rare and unusual complication of a mature cystic teratoma, where it mimics peritoneal carcinomatosis, leading to an initial misdiagnosis. While ruptured mature cystic teratomas are known, the granulomatous inflammation and peritonitis that mimicked pseudomyxoma peritonei have not been reported in the literature. This novel presentation could significantly affect diagnostic protocols in similar cases, as it provides insight into how granulomatous reactions can present similarly to malignancy, potentially leading to unnecessary aggressive treatments such as cytoreductive surgery and hyperthermic intraperitoneal chemotherapy.

Immune-related adverse events (irAE) are a concern during immune checkpoint inhibitor therapy (ICI), and vasculitis is a rheumatic irAE. Granulomatosis with polyangiitis (GPA) is an anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis characterized by necrotizing granulomatosis. GPA in the mammary glands is rare and causes granulomatous mastitis. We describe an older woman with metastatic hepatocellular carcinoma who was receiving ICI therapy. She developed a rapidly growing painful mass in her right breast. Biopsy of the breast revealed necrotizing granulomatous mastitis, which implied an association with autoimmune disease. We detected c-ANCA (proteinase 3)-positivity and a nodule forming a cavity in her right lung; lung biopsy revealed granulomatosis. We diagnosed GPA, possibly arising as an irAE. Prompt initiation of prednisolone therapy led to complete resolution of clinical symptoms within 2 weeks. This case represents the first known report of rare autoimmune mastitis with GPA flared after ICI therapy.

Intramedullary spinal cord metastasis (ISCM) is a rare condition. ISCM from esophageal cancer is extremely uncommon. We report a rare case of lumbar ISCM from esophageal cancer in a woman in her 70 s, initially diagnosed with clinical stage IVA (cT4bN1M0) esophageal cancer. She underwent definitive radiotherapy (60 Gy in 30 fractions) with concurrent chemotherapy of 5-fluorouracil and cisplatin (FP), followed by two additional cycles of FP chemotherapy. A complete response was maintained for 1 year and 7 months post-radiotherapy by endoscopy. However, the patient began to experience mild bladder and rectal dysfunction and back pain. 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) revealed high FDG uptake in the spinal cord cavity at the L1 level and contrast-enhanced spinal magnetic resonance imaging (MRI) showed an intramedullary tumor corresponding to the areas of FDG accumulation. Based on the appearance of new lesions and elevated tumor markers, the lesion was diagnosed as ISCM from esophageal cancer rather than a primary spinal cord tumor, and palliative radiotherapy (20 Gy in 5 fractions) was promptly administered. Two months after radiotherapy, the patient's neurologic symptoms improved, and she continued treatment with immune chemotherapy. To our knowledge, this is the first reported case of immune checkpoint inhibitors after the diagnosis of ISCM from esophageal cancer. Although rare, ISCM should be considered in cancer patients presenting with new neurological symptoms, and timely multidisciplinary intervention is essential for optimal management.

Anal cancer is a rare malignancy that accounts for only 0.3% of all cancer cases. Clinical data on treatment strategies for patients with special conditions, such as impaired renal function or those undergoing dialysis, are limited. Herein, we report a case highlighting the efficacy and safety of a combination regimen of mitomycin C (MMC), 5-fluorouracil (5-FU), and radiotherapy (RT) in a patient undergoing dialysis. A 65 year-old woman undergoing hemodialysis three times per week for chronic kidney disease associated with polycystic kidney disease presented with hematochezia. Biopsy confirmed human papillomavirus (HPV)-related anal squamous cell carcinoma, clinical stage cT1N0M0 (Stage I). The patient underwent two cycles of MMC and 5-FU combined with RT. The adverse events included grade 3 neutropenia, grade 3 thrombocytopenia, grade 2 nausea, grade 1 vomiting, and grade 3 diarrhea. Post-treatment endoscopic and histological evaluations confirmed a complete response. This case suggests that MMC + 5-FU + RT may be a viable treatment option with manageable toxicity, even in patients with anal canal cancer undergoing dialysis.

Gastrointestinal stromal tumors (GISTs) harboring the PDGFRA D842Y mutation are extremely rare, and their clinicopathological features have not been characterized to date. Hyogo Medical University has maintained a genetic database of GISTs, including resection cases from Niigata University, since 2003. This database contains information on patient demographics, tumor genotypes (KIT and PDGFRA), tumor size, histological features, and immunohistochemical findings. As of December 2024, 1,024 primary GIST cases had been analyzed, and four cases harboring the PDGFRA D842Y mutation were identified and included in this study. All four patients (three men, aged 57-82 years) had large gastric tumors, measuring 9.8-18.7 cm in diameter. All tumors harbored a c.2527G > T substitution in exon 18 of PDGFRA, resulting in a D842Y mutation. Histologically, all tumors exhibited epithelioid morphology. KIT expression was absent or markedly reduced, whereas DOG1 was consistently strongly expressed. Three patients presented with an acute abdomen and subsequently underwent surgery. The remaining patient had an unresectable tumor and received tyrosine kinase inhibitor therapy; however, sequential treatment with imatinib and sunitinib was clinically ineffective. PDGFRA D842Y-mutant GISTs share histopathological features with D842V-mutant tumors, including gastric origin, epithelioid morphology, and low KIT expression. However, their clinical behavior differs: D842Y-mutant GISTs consistently present as large, hypervascular tumors associated with acute complications. The therapeutic efficacy of tyrosine kinase inhibitors remains unclear, underscoring the need for further case accumulation to better define the clinical course and determine optimal treatment strategies for this rare subtype.

This case highlights the potential for early emergence of neuroendocrine differentiation in patients with metastatic castration-sensitive prostate cancer undergoing triplet therapy with androgen deprivation therapy, darolutamide, and docetaxel, even with marked prostate-specific antigen (PSA) suppression. In this patient, although some lesions initially responded to treatment, new metastases and radiological progression were observed early after triplet therapy was initiated. These atypical progression patterns raised the suspicion of neuroendocrine prostate cancer (NEPC), confirmed by percutaneous biopsy of an enlarged right external iliac lymph node. This enabled the timely modification of the treatment strategy. Furthermore, retrospective immunohistochemical reevaluation of the diagnostic prostate biopsy specimen obtained at the referring hospital using only four cores revealed focal neuroendocrine differentiation within the poorly differentiated Gleason pattern 5 areas, suggesting that de novo NEPC features may have been present at the time of diagnosis. As triplet therapy has become more widespread, the incidence of NEPC may increase. Clinicians should maintain a high level of vigilance for discordant PSA progression and consider early biopsy of metastatic lesions to ensure accurate diagnosis and appropriate therapeutic decision-making.

Emphysematous osteomyelitis (EOM) is defined as the presence of gas forming bacteria within bones. It is seen in patients with morbid conditions like immunosuppression, diabetes, patients on chemotherapy, in cancer patients and in intravenous drug abusers. We present two cases of emphysematous osteomyelitis in patients with hematological malignancies; lymphoma and leukemia. Both the patients had similar clinical presentations with fever, localized swelling, and pain. Both patients underwent sonography (USG) and contrast-enhanced computed tomography (CECT) and imaging diagnosis of EOM was made. Microbiological confirmation of the causative organism was done and patients were started on appropriate antibiotics. Both patients responded very well to the treatment. Imaging findings and treatment outcomes are discussed, highlighting the challenges in managing this rare complication.

Hereditary leiomyomatosis and renal cell carcinoma syndrome (HLRCC) is an autosomal dominant disorder caused by germline loss-of-function mutations in the fumarate hydratase (FH) gene. It is characterized by cutaneous and uterine leiomyomas and an increased risk of highly aggressive renal cell carcinoma (RCC), often associated with poor prognosis. We report the case of a 31-year-old Japanese woman diagnosed with unresectable RCC with nodal and adrenal metastases. Histopathological analysis of a biopsy specimen suggested papillary RCC; however, cancer genome profiling revealed a presumed germline pathogenic variant in FH. Subsequent germline testing confirmed the FH mutation, establishing the diagnosis of HLRCC-associated RCC. Cascade genetic testing identified several asymptomatic relatives carrying the same germline FH variant. Immunohistochemistry (IHC) revealed unexpected positivity for FH and S-(2-succinyl) cysteine in tumor cells. Although FH loss is a hallmark of HLRCC-associated renal cell carcinoma, rare cases, such as this one, may exhibit retained FH expression on IHC. The patient was treated with a combination of lenvatinib and pembrolizumab, achieving a sustained partial response for 18 months following treatment initiation.

Supplementary information: The online version contains supplementary material available at 10.1007/s13691-025-00811-9.

Well-leg compartment syndrome is a rare yet serious postoperative complication that may develop in limbs not directly involved in surgery. Prompt diagnosis and intervention are essential for limb preservation and optimal recovery. Several risk factors have been identified; however, preoperative prediction remains challenging. This report highlights the importance of early diagnosis through compartment pressure measurement in managing well-leg compartment syndrome following pelvic surgery. A 59-year-old female patient with cervical cancer underwent an open radical hysterectomy. In the immediate postoperative period, she reported right calf pain. As she could not communicate effectively during recovery, intramuscular compartment pressure was promptly measured using an 18-gauge needle and an arterial pressure monitoring system. Elevated pressure confirmed the diagnosis, and an emergency fasciotomy was performed. Rehabilitation and contracture prophylaxis were initiated the following day. The patient regained independent ambulation and completed postoperative chemoradiotherapy, with no evidence of recurrence. Early intervention facilitated a favorable outcome.

Urachal cancer is a rare malignancy, and cases with neuroendocrine features are extremely uncommon. We present a man in his 30s with gross hematuria. Imaging revealed a nodular mass in the bladder dome with lung metastases. Histopathology after transurethral and open resection revealed a large cell neuroendocrine carcinoma arising from the urachus. Comprehensive genomic profiling (CGP) identified FGFR2-TACC2 fusion, TP53 mutation, and Rb1 loss. These findings suggest that targeted therapy may be considered in such rare and aggressive variants.