Retroperitoneal T-cell lymphoma with cystitis and megacolon in a young feline leukaemia virus-positive cat.

This is a case of a 66-year-old female with a past medical history of stage III clear cell ovarian carcinoma (CCOC), status post chemotherapy and radical hysterectomy, who was incidentally found to have a metastatic retroperitoneal mass ten years later during a workup for persistent and vague thigh pain. Her pain was initially treated conservatively, and she was told to follow up in 3 months after attempting conservative measures such as over-the-counter pain medications and physical therapy. Despite adhering to these recommendations, here pain persisted, and a subsequent MRI revealed an unresectable presacral mass that was consistent with metastatic recurrence of clear cell carcinoma, for which the patient agreed to proceed with recommended palliative radiation therapy.

A 3-month-old female infant was admitted for incessant crying for 3 days. Examination revealed a rapidly growing massive retroperitoneal mass that was difficult to resect. Needle biopsy confirmed infantile fibrosarcoma. Initial chemotherapy with the VAC regimen (vincristine, actinomycin D, and cyclophosphamide) was administered, but the response was poor. The common fusion in infantile fibrosarcoma is ETV6-NTRK3, and next-generation sequencing detected an RBPMS-NTRK3 gene fusion in this patient. To our knowledge, this is the first reported case of infantile fibrosarcoma with RBPMS-NTRK3 fusion in China. Treatment with larotrectinib resulted in marked tumor shrinkage.

ABSTRACTIntroductionWe present a technique that combines a fluorescent ureteral catheter with Firefly near‐infrared fluorescence imaging to identify the ureter and avoid injury during robot‐assisted resection of a retroperitoneal cystic tumor.Case PresentationComputed tomography revealed a 6‐cm retroperitoneal cystic mass anterior to the abdominal aorta near the lower pole of the left kidney that adhered to the left ureter in a 53‐year‐old man. A fluorescent ureteral catheter was placed preoperatively, and robot‐assisted transperitoneal resection was performed. Firefly imaging enabled clear visualization of the ureter, allowing safe dissection and tumor identification. The tumor was excised without cyst rupture. The console time was 4 h 13 min, with minimal blood loss. Pathology confirmed schwannoma.ConclusionWe demonstrated the feasibility and clinical benefits of integrating a fluorescent ureteral catheter with Firefly fluorescence imaging for intraoperative ureteral identification during robot‐assisted surgery. This fluorescence‐guided approach improves dissection accuracy and helps prevent ureteral injury.

Primary retroperitoneal tumors are rare and can encompass a large range of pathologies, including both benign and malignant etiologies. Retroperitoneal tumors with a vascular component constitute a small percentage of these tumors, and include intravascular and extravascular leiomyosarcoma, paraganglioma, extrarenal angiomyolipoma, Castleman disease, angiosarcoma, hemangioma, cystic lymphangioma, and inflammatory myofibroblastic tumor. Cross-sectional imaging is often valuable to characterize vascular retroperitoneal masses and delineate their relationship with surrounding anatomical structures, aiding in surgical planning. This article aims to review the imaging features of these vascular retroperitoneal tumors and presents a diagnostic approach to aid in diagnosing these tumors.

Abstract Introduction While obesity is a recognized contributor to erectile dysfunction (ED), the impact of early-life obesity on the long-term function of the corpus cavernosum (CC) and pudendal artery (PA) is not well defined. We hypothesized that nutritional overload in early development triggers cellular senescence and structural changes, impairing neurovascular components of erectile function in adulthood. Objective We hypothesized that nutritional overload in early development triggers cellular senescence and structural changes, impairing neurovascular components of erectile function in adulthood. To determine whether early-life overnutrition induces long-term structural and functional alterations in the corpus cavernosum and pudendal artery. We aimed to assess cavernous and vascular reactivity, along with molecular markers of senescence and tissue remodeling, using a rat model of postnatal nutritional overload. Methods Wistar rats were nursed in small litter (SL; 3 pups/dam) to induce postnatal overnutrition or in normal litter (NL; 10 pups/dam) as controls. After weaning on postnatal day (PND) 21, animals were maintained on standard chow until PND160. Body weight, fat pad mass, and systolic blood pressure (SBP) were recorded. Functional assays in CC and PA evaluated responses to phenylephrine (PE), acetylcholine (ACh), and electrical field stimulation (EFS). Transcriptomic profiling by RNA sequencing and gene validation via RT-qPCR were conducted to investigate markers of senescence and tissue remodeling. Results Final body mass did not differ between groups, but SL rats exhibited higher retroperitoneal and perigonadal fat mass, along with elevated SBP (SL: 120.5 ± 1.2 mmHg vs NL: 114.9 ± 0.58 mmHg). In the CC, EFS-induced relaxation was reduced in SL animals (16 Hz: SL 2.39 ± 0.53 mN vs NL 3.06 ± 0.28 mN), while PE- and EFS-induced contractions were increased and partially reversed by indomethacin, suggesting prostanoid involvement. In the PA, ACh-mediated relaxation was significantly impaired (Emax: SL 28 ± 6% vs NL 68 ± 5.5%), without changes in PE-induced tone. Transcriptomic analysis revealed 124 differentially expressed genes (DEGs) in the CC, 99 in male PA, and 252 in female PA. Enrichment mapping in male tissues highlighted pathways involved in extracellular matrix remodeling, metabolic control, and secretin-related GPCR signaling (e.g., Col1a1, Fstl3, Adamts6, Thbs6, PI3K-Akt-mTOR). In contrast, DEGs in female PA were enriched for innate immune and metabolic/hormonal response pathways. RT-qPCR in CC confirmed increased Bgn and Col1a2, along with altered expression of Calcrl, Vipr2, and Glp1/2r, consistent with senescence-associated remodeling. Cross-tissue comparison identified 11 shared genes, possibly involved in neurovascular tone, metabolic stress responses, and architectural remodeling. Conclusions Early-life obesity induces persistent structural and functional alterations in erectile and pudendal tissues, likely contributing to erectile dysfunction in adulthood. These changes appear to be mediated by pathways involving senescence, fibrosis, and secretin GPCR signaling. Additionally, the identification of shared molecular signatures across tissues highlights a potential neurovascular-metabolic axis disrupted by early metabolic stress. Ongoing studies aim to elucidate the specific roles of these candidate genes and pathways in the pathophysiology of obesity-induced sexual dysfunction. Disclosure No

A novel tocopherol derivative suppresses obesity in high-fat diet-induced obese mice.

Leiomyosarcoma of the inferior vena cava (IVC) is a rare and aggressive malignancy, with poor prognosis and no universally accepted treatment protocol. We present the case of a 69-year-old male with an IVC leiomyosarcoma, which extended from the common iliac veins to the right renal vein. Initial imaging showed a retroperitoneal mass with suspected IVC involvement. Histopathological examination confirmed leiomyosarcoma, and the patient underwent four chemotherapy cycles with doxorubicin, followed by surgical resection. A multidisciplinary approach, including general, vascular, and urologic surgeons, was employed. The tumor was excised en bloc with the IVC and right kidney. No prosthetic IVC reconstruction was necessary due to the lack of hemodynamic changes after clamping. Postoperative recovery was uneventful except for mild renal impairment. Molecular profiling of the tumor using next-generation sequencing (NGS) identified mutations in TP53, RB1, KMT2C, TSC2, and other genes associated with chromatin stability and tumor suppression. The patient experienced a local recurrence at four months and was treated with chemotherapy. This case underscores the importance of personalized treatment strategies, including surgical decision-making, chemotherapy, and molecular characterization, in managing rare tumors like IVC leiomyosarcoma. Further research is needed to explore potential oncogenic targets and improve prognosis.

Pharmacokinetic failure of obinutuzumab due to massive third-space sequestration in a patient with high-burden follicular lymphoma: A rationale for therapeutic drug monitoring and dose intensification

Foetus-In-Foetu (FIF) is a congenital anomaly that involves the presence of a deformed parasitic twin within its host, most commonly presenting as a retroperitoneal mass at birth. Present case is of a 1.5-month-old female who was referred for elective excision of a gigantic abdominal mass diagnosed antenatally on an anomaly scan in the third trimester. Postnatal imaging showed an enormous retroperitoneal solid-cystic mass with displacement of the surrounding organs, Magnetic Resonance Imaging (MRI) showed consistent findings of a benign mature cystic teratoma. The clinical presentation was in the form of repeated vomiting with feeds, without systemic compromise. Induction of anaesthesia was done by balanced technique, utilising intravenous propofol, fentanyl and atracurium, followed by pressure-controlled ventilation and sevoflurane with oxygen-air for maintenance. Following induction, a single-shot caudal block using 0.2% ropivacaine (0.5 mL/kg) was given under strict asepsis with a 25G short-bevel styletted needle. It gave adequate analgesia for 6-8 hours without any complications. Surgical resection was by removal of the mass and right kidney with minimal blood loss and no transfusion or inotropic support. The postoperative course was uneventful and histopathological study revealed an immature teratoma with features of FIF type containing vertebral and limb elements. The current case emphasises the need for tailored anaesthetic approaches to neonatal FIF, with special reference to the usefulness of caudal analgesia in effective pain relief and opioid-sparing regimen. It also emphasises the imaging diagnostic significance, surgical removal as a gold standard for therapy and follow-up over a long period due to the risk of malignant transformation.

Abstract Introduction/Objective Extracavitary primary effusion lymphoma (EC-PEL) is a rare and aggressive HHV8 and EBV-associated B-cell lymphoma that presents as a solid tumor rather than a typical effusion. With few reported cases, it remains underrecognized. EC-PEL often affects immunocompromised individuals, particularly those with HIV. Methods/Case Report A 46-year-old HIV-positive male presented with abdominal pain, nausea, vomiting, and fever. Imaging revealed a large retroperitoneal mass with pancreatic invasion, encasement of vascular structures, and retroperitoneal lymphadenopathy. Fine needle aspiration of the mass showed numerous dispersed neoplastic cells with immunoblastic, plasmablastic, or anaplastic features. Immunostains showed that the neoplastic cells were positive for CD138, MUM-1, CD4, CD30, HHV-8 and EBER, while negative for CD3, CD5, CD20, PAX5, CD79a, ALK, Cyclin D1 and TdT. In situ hybridization studies demonstrated a lambda-restricted pattern, consistent with diagnosis of EC-PEL. Clonal B cell immunoglobulin kappa rearrangement was detected by PCR. Bone marrow biopsy was negative. The patient underwent chemotherapy initially, but his condition deteriorated and passed away two months after the diagnosis. Results NA Conclusion EC-PEL can pose a diagnostic challenge due to the absence of common B- and T-cell markers. Early recognition of this rare entity, along with appropriate tissue acquisition, is crucial. Adequate cytology specimens can lead to an accurate diagnosis.

Abstract Context Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous and aggressive malignancy with varied clinical presentations, molecular features, and prognostic factors. This retrospective study aimed to analyze 23 distinct DLBCL cases, emphasizing common clinical, molecular, and genetic characteristics, especially in the elderly female population. Design A cohort of 23 DLBCL patients was retrospectively reviewed, with 72% being elderly females over 70 years. Accurate diagnosis was confirmed through histology, immunohistochemistry (IHC), fluorescence in situ hybridization (FISH), next-generation sequencing (NGS), and B-cell rearrangement studies. The cell origin classification of dividing DLBCL into germinal center type (GCB) or activated b cell type (ABC) was used based on IHC expression of CD10, BCL6 and MUM-1/IRF4. Results The most frequent and prominent anatomic locations were cervical lymph nodes and retroperitoneal masses. MYC, BCL2, and BCL6 rearrangements were identified in four 17.4 %(4/23) , 17.4%(4/23) and 21.7%(5/23) cases, respectively. A rare and remarkable case of triple-hit lymphoma was observed in a 3-year-old female, exhibiting rearrangements in all three genes. One case of DLBCL-ABC type was found to have MYD88 p.L268P mutation along with CD79B mutation,B lymphocyte induced maturation protein-1 (BLIPM-1) mutation and CDKN2A deletion. Poor prognostic markers, including biallelic TP53 mutations, CDK2A deletions and MYC rearrangement with BCL2 /BCL6 translocations were detected in select cases. Additionally, eight cases showed no conventional DLBCL FISH panel aberrations, highlighting significant genetic and molecular diversity. Conclusion This study underscores the remarkable molecular complexity and clinical heterogeneity of DLBCL, particularly in elderly females. It highlights the critical importance of advanced and comprehensive diagnostic techniques, such as FISH, NGS, and B-cell rearrangement studies. The identification of triple-hit lymphoma and the mutational prognostic markers emphasises the need for an accurate and nuanced diagnostic approach. Furthermore, the detection of prognostic markers significantly influences the therapeutic strategy and clinical outcomes.. The absence of conventional FISH panel aberrations demonstrates the considerable genetic diversity of DLBCL.

ABSTRACTPrimary presacral clear cell carcinoma (CCC) of Müllerian origin is extremely rare. Malignant transformation of endometriosis is a known phenomenon, though typically involving the ovaries or pelvic peritoneum. Retroperitoneal presentation, especially decades after definitive surgery, is exceedingly uncommon. A 60‐year‐old woman presented with a large retroperitoneal/presacral pelvic mass leading to hydronephrosis, 20 years after total abdominal hysterectomy and bilateral salpingo‐oophorectomy for endometriosis. MRI showed a cystic‐solid mass with mural nodularity. Surgical exploration revealed dense retroperitoneal adhesions with involvement of the rectosigmoid and the appendix. En bloc resection was performed in posterior exenterative fashion. Histopathology confirmed clear cell carcinoma arising from endometriotic foci, fulfilling Sampson's criteria. Postoperative management included adjuvant paclitaxel‐carboplatin chemotherapy. The patient recovered uneventfully and was scheduled for ileostomy reversal. This case illustrates the potential late malignant transformation of endometriosis into Müllerian CCC even decades after hysterectomy and oophorectomy. Endometriosis‐associated carcinoma should be considered in the differential diagnosis of retroperitoneal pelvic masses, particularly in women with prior endometriosis.

Supernumerary kidney is an extremely rare congenital anomaly, defined by the presence of an additional kidney with its own capsule, blood supply, and collecting system. Even more unusual is the occurrence of a supernumerary kidney associated with a fusion anomaly such as a sigmoid kidney, in which the renal units are joined in an S-shaped configuration. We report the case of a 33-year-old woman in whom a supernumerary kidney forming a sigmoid fusion pattern was identified an abdominal CT performed for abdominal pains accentuated in the lumbar area. Imaging demonstrated three renal units, with the lower supernumerary kidney fused to the contralateral kidney in a sigmoid arrangement, each possessing its own collecting system and vascular supply. No associated obstruction, calculi, or infection were observed. Recognition of such rare anomalies is important, as they may be mistaken for renal or retroperitoneal masses and can present significant challenges during surgical or interventional procedures. This case contributes to the limited literature on supernumerary kidneys with sigmoid fusion and underlines the value of detailed radiological evaluation for accurate diagnosis and management planning.

Disclosure: S. Modi: None. A. Sahu: None. L. Belalcazar: None.Background: The diagnosis of pheochromocytoma relies on increased catecholamine levels and typical imaging characteristics. However, end-stage renal disease (ESRD) brings diagnostic challenges, with an impact on defining clinical, biochemical, and imaging criteria. We present a case of a patient with a pheochromocytoma and discuss the diagnostic and therapeutic intricacies posed by his long history of ESRD. Clinical Case: A 43-year-old male with an 8-year history of hypertension and ESRD on dialysis presented to the hospital for excision of an infected arteriovenous graft and permcath removal. He had no symptoms suggestive of catecholamine excess. Blood pressure on admission was 144/84 mmHg and heart rate 83 beats per minute. A CT venogram with contrast, ordered for fistula workup, revealed an incidental retroperitoneal mass. Further evaluation with a CT abdomen with contrast showed a right adrenal mass measuring 4.8 x 5.4 x 6.3 cm with an attenuation of 74 Hounsfield units (HU), but an unexpected increased absolute washout of 87%. Plasma metanephrines (MN) and normetanephrine (NMN) were obtained and found to be 4.53 nmol/L (Ref 0-0.49 nmol/L) and 15.80 nmol/L (Ref 0-0.89 nmol/L), respectively, confirming the presence of a pheochromocytoma. Patient received ten days of alpha blockade with doxazosin 8 mg twice a day; metoprolol 12.5 mg twice a day was added three days prior to surgery for beta blockade. He underwent successful laparoscopic right adrenalectomy. Pathology confirmed a 5 cm pheochromocytoma. Conclusion: This case illustrates how ESRD may complicate the diagnosis of pheochromocytoma. In this patient, worsening hypertension attributed to his renal disease likely delayed the diagnosis of pheochromocytoma. Although in ESRD MN and NMN are typically elevated, they remain within 1.5 times the reference range unless a catecholamine-producing tumor is present. In our patient, the adrenal mass had characteristic high attenuation and plasma MN and NMN levels that were clearly elevated (9 and 17 times the upper limit of normal, respectively), even in the setting of ESRD. Furthermore, the patient’s underlying ESRD explains the atypical increased contrast washout seen on adrenal imaging. ESRD causes decreased renal clearance and contrast retention. Retained iodine increases tissue attenuation, elevating post-contrast HU and creating a large pre- and post-contrast difference that artificially elevates the absolute washout as seen in our patient.Presentation: Saturday, July 12, 2025

Introduction : Retroperitoneal liposarcoma (RLPS) is a rare mesenchymal malignancy characterized by large tumor size at diagnosis and a high propensity for local recurrence. Giant RLPS, particularly the high-grade dedifferentiated subtype, presents formidable diagnostic and therapeutic challenges. Case Illustration : We present the case of a 64-year-old male with a one-year history of progressive abdominal distension. Physical examination revealed a massive, firm abdominal mass. Contrast-enhanced computed tomography (CT) identified a 35 x 25 x 20 cm heterogeneous retroperitoneal mass with both fatty and large non-lipomatous components, consistent with dedifferentiated liposarcoma. The patient underwent an exploratory laparotomy with a successful en bloc compartmental resection, which included the tumor, the right kidney, the right adrenal gland, and a segment of the ascending colon. The resected specimen weighed 10.4 kg. Histopathology confirmed a grade 3 dedifferentiated liposarcoma arising from a well-differentiated liposarcoma, with negative surgical margins (R0). The patient had an uneventful postoperative recovery and is undergoing surveillance. Discussion : This case highlights the central role of radical surgical resection as the only potentially curative modality for primary RLPS. The discussion provides a comprehensive review of the diagnostic utility of cross-sectional imaging, the principles of compartmental surgery to achieve negative margins, and the current, evolving landscape of adjuvant therapies. We critically analyze the results of the landmark EORTC-STRASS trial, which failed to show an overall benefit for preoperative radiotherapy but suggested a potential benefit in the liposarcoma subgroup, creating an ongoing clinical controversy. The limited role of systemic therapy outside of the advanced or metastatic setting is also reviewed. Conclusion : The management of giant RLPS is complex and necessitates a multidisciplinary approach at a specialized sarcoma center. Complete surgical resection remains the cornerstone of treatment, while the role of neoadjuvant therapies continues to be refined through histology-specific clinical trials.

ABSTRACT Introduction: Primary retroperitoneal masses are neoplasms that originate within the retroperitoneal space, independent of any retroperitoneal organs. Although rare, they present significant diagnostic and therapeutic challenges. Materials and Methods: This study was performed in the Department of Pathology and Lab Medicine at AIIMS Raipur over a period of 2 years. It included both retrospective and prospective cases. Relevant clinical details and radiological investigations were reviewed. Histopathological findings and results from ancillary studies were analyzed and correlated with the clinical data. Results: The study reported 15 cases of primary retroperitoneal masses, with a higher occurrence in males. Most patients were in their 50s to 60s. Both benign and malignant neoplasms were observed. Three uncommon cases included one extra-skeletal osteosarcoma and two extra-skeletal Ewing sarcomas. Conclusion: Retroperitoneal tumors present diagnostic challenges and therapeutic complexities due to their rarity, often late presentation, and anatomical location near vital structures in the retroperitoneal space. Accurate diagnosis is crucial for appropriate management and prognostication.

ABSTRACTXanthogranulomatous oophoritis is an extremely rare, chronic inflammatory condition of the ovary characterized by the replacement of normal ovarian tissue with lipid‐laden macrophages, plasma cells, and lymphocytes. When the genital tract is involved, this most commonly affects the endometrium, whereas ovarian and fallopian tube involvement is rare. It is often misdiagnosed due to its nonspecific clinical and radiological features, which can mimic neoplastic or infectious pathologies. This case report highlights a rare presentation in a pediatric patient and emphasizes the diagnostic challenges encountered, especially in low‐resource settings. To the best of our knowledge, this is the first reported case of its kind in Tanzania. We report a rare case of an 8‐year‐old girl who presented to our specialty hospital in Northern Tanzania with a history of progressive abdominal distension for 8 months. An abdominal CT scan with contrast revealed a large, heterogeneous, enhancing retroperitoneal mass with central necrosis, measuring 13 × 13 × 10 cm. The mass displaced the intestines superolaterally, compressed the urinary bladder inferiorly, and displaced the ureters laterally, resulting in bilateral hydroureteronephrosis. It abutted the bilateral iliac arteries and compressed the sigmoid colon. Multiple enlarged para‐aortic, periportal, and mesorectal lymph nodes were visualized, the largest measuring 2 × 2 cm. There was minimal free intraperitoneal fluid, and a CT scan of the chest with contrast revealed two micronodules in the anterior segment of the right upper lobe of the lung. Radiological findings were suggestive of a retroperitoneal tumor with pulmonary metastases. Based on clinical and radiological findings, a working diagnosis of Neuroblastoma was made. The patient was initiated on a standard Neuroblastoma chemotherapy protocol and received three cycles, which resulted in a significant reduction in tumor size. Subsequently, she underwent an exploratory laparotomy, during which a left salpingo‐oophorectomy was performed. Postoperative recovery was uneventful and the patient was discharged in stable condition. The final histopathological report showed xanthogranulomatous salpingo‐oophoritis, thus excluding the initial diagnosis of malignancy.

Primary testicular lymphoma (PTL) is a rare, aggressive extranodal non-Hodgkin’s lymphoma, most commonly affecting older men. Bilateral testicular involvement is particularly uncommon and indicates a poorer prognosis. We report the case of a 58-year-old male presenting with bilateral scrotal swelling, systemic symptoms, and significant retroperitoneal lymphadenopathy. Imaging revealed a lobulated retroperitoneal mass encasing major vessels and bilateral testicular enlargement with necrosis. Bilateral orchiectomy followed by histopathology confirmed diffuse large B-cell lymphoma, nongerminal center type. FDG PET-CT showed extensive nodal involvement and intense uptake in the third ventricle, suggestive of possible central nervous system (CNS) dissemination. The disease was staged as Ann Arbor stage IV, and the patient was referred for systemic chemotherapy with CNS-directed prophylaxis. This case underscores the importance of early recognition, multimodal imaging, and histopathological confirmation in diagnosing PTL and highlights the need for CNS surveillance and multidisciplinary management in advanced presentations.

A boy in early childhood presented to the emergency department due to headache and eye pain. Blood pressure was not recorded with intake of vital signs. A CT head was obtained, which was negative. On return from CT, he was found to be in hypertensive emergency, with blood pressures of 190s/140s in all four extremities. A renal bladder ultrasound with Doppler showed a left retroperitoneal mass, and abdominal CT with contrast confirmed a mass consistent with a neuroblastoma. He was admitted to the PICU for blood pressure stabilisation and subsequently transferred to the oncology service where he was definitively diagnosed with neuroblastoma and started on chemotherapy. This case is an unusual presentation of a neuroblastoma as a hypertensive emergency. It highlights the importance of obtaining triage blood pressure for acute care paediatric patients and of creating a follow-up plan with families for abnormal readings and not prematurely attributing them to patient cooperation.