Pediatric urolithiasis, though uncommon, carries significant morbidity when driven by underlying metabolic disorders. Classical homocystinuria, caused by cystathionine beta-synthase (CBS) deficiency, is a rare autosomal recessive inborn error of sulfur amino acid metabolism. While ectopia lentis, skeletal anomalies, and thromboembolic events define its classical triad, urolithiasis presenting within the first year of life remains exceptionally rare in surgical literature. A one-year-old male, born to consanguineous parents with known homocystinuria, presented with gravel-like urinary deposits since five months and progressive dysuria since six months. Ultrasonography revealed a 10 mm right renal calculus, a 23 mm vesical calculus, and features of chronic cystitis. He underwent cystolithoscopy, open cystolitholapaxy, and double-J (DJ) stenting. Repeat imaging at two months revealed a 17 mm right staghorn calculus with mild hydronephroureterosis. Intraoperatively, an intraparenchymal pelvis was encountered with the staghorn calculus densely adherent to the indwelling stent, precluding conventional retrieval. Nephrectomy was deferred in favour of nephron-sparing surgery. The calculus was extracted en bloc, a fresh DJ stent inserted, and watertight ureteral re-anastomosis performed. Homocystinuria can drive aggressive multi-level urolithiasis in infancy. Open pyelolithotomy with ureteral re-anastomosis remains a viable nephron-saving strategy when minimally invasive approaches are anatomically unfeasible. Sustained metabolic-surgical multidisciplinary management is essential for long-term renal preservation.

Total laparoscopic hysterectomy (TLH) for enlarged uteri presents a significant challenge for surgeons due to limited surgical field exposure, increasing the risk of injury to the bowel, bladder, ureters, and blood vessels. To minimize these intraoperative complications, a surgical approach known as "The Ship Theory" has been developed at our center. According to this concept, the uterus is likened to a large vessel moored within the pelvis. As its supporting ligaments ("anchors") are progressively released, the uterus gains mobility, allowing it to migrate into the abdominal cavity. This enhanced mobility improves visualization and facilitates surgical access, enabling a safer and more effective TLH for large uteri. Using this approach, we successfully performed this procedure on a 51-year-old female patient with uterine leiomyomas and metrorrhagia. Preoperative imaging revealed a uterus measuring 189 × 158 × 148 mm. Institutional review board and ethics committee approval was obtained. The total operative time was approximately 90 min, with an estimated blood loss of less than 50 mL. The patient was discharged 48 h postoperatively without complications. This technical report demonstrates that the application of a minimally invasive surgical technique for uteri with significant spatial constraints-as outlined in "The Ship Theory"-is not only feasible but can be successfully executed when performed in a systematic and structured manner.

Spindle cell rhabdomyosarcomas (SCRMS), recognized by the 2020 World Health Organization Classification of Tumors of Soft Tissue and Bone as a distinct entity, comprise a family of malignant skeletal muscle tumors sharing spindle cell morphology. To date, members of this family include (1) MyoD1-mutated SCRMS/sclerosing rhabdomyosarcomas (RMS), (2) intraosseous SCRMS with FET::TFCP2 or MEIS1::NCOA2 fusions, and (3) infantile/congenital SCRMS harboring NCOA1/2 or VGLL3 rearrangements. A rare, emerging subtype of SCRMS has been reported to harbor recurrent ZFP64::NCOA3 fusions. We studied 14 cases of this rare SCRMS subtype. The tumors presented in 11 men and 3 women (median age, 39.5 years; range, 22-69 years) and involved the thigh (4), lower leg (2), gluteal soft tissues (2), abdominal wall (1), mediastinum (1), subperiosteal surface of third rib (1), glottis (1), prostate (1), and pelvis (1). Morphologically, 11 tumors showed uniform spindle cell morphology with a fascicular architecture, whereas the remaining 3 tumors demonstrated focal or predominant round cell morphology. Extensive chondro-osseous differentiation was seen in 2 cases. By immunohistochemistry, tumors were variably positive for both desmin and MyoD1 (6 tumors), desmin, MyoD1, and myogenin (1 tumor), desmin alone (3 tumors of which only 1 was also tested for MyoD1), or MyoD1 alone (3 tumors). Smooth muscle actin was noted in 6 of 10 tested cases, and 2 of 5 tested cases showed ALK expression. A ZFP64::NCOA3 fusion was detected in 8 tumors, and a ZFP64::NCOA2 fusion was detected in 6 tumors. Methylation studies showed all but 1 tested tumor to form a tight cluster, clearly separate from other RMS subtypes and non-RMS morphologic mimics. Clinical follow-up (10/14 cases; median, 35 months; range, 3-108 months) demonstrated local recurrence in 2 patients and distant metastases in 5 patients (median, 12 months; range, at presentation - 106 months). At the time of last follow-up, 5 patients were alive without evidence of disease, 3 patients were alive with disease, and 2 patients died of disease at 34 and 108 months. We conclude that SCRMS with ZFP64::NCOA2/3 fusions represents a distinct, clinically aggressive sarcoma characterized by fascicular and sometimes round cell morphology, occasional chondro-osseous differentiation, and variable skeletal muscle marker expression. Recognition of this emerging subtype of SCRMS may have prognostic and therapeutic implications.

The FRMD5-associated neurodevelopmental disorder is characterized by early-onset abnormal eye movements, seizures, ataxia, nonepileptic myoclonus, and developmental delay with only symptomatic treatment available. Opsoclonus-myoclonus-ataxia syndrome has similar features with well-established immunomodulatory treatment. We present a case of a patient with a de novo FRMD5 variant responsive to steroid pulse therapy and provide phenotypic-genotypic correlation based on our case and reported data.

Neuroblastoma is the most common extra-cranial solid tumor in children under the age of five years and is the second most prevalent malignancy in children after acute lymphoblastic leukemia. We are presenting two cases of neuroblastoma in children presented as intra-pelvic masses. The first patient presented with urinary retention while the second patient presented with ataxia. The initial imaging including ultrasound, CT scan, and MRI showed a large solid mass in the pelvis in both patients with extension to the spinal canal through the neural foramina at different levels. The histopathological results confirmed pelvic neuroblastomas. These cases highlight the rare locations of neuroblastoma in children and emphasize the variable presentations of this rare location. Knowledge of possible presentations of neuroblastoma aids early detection and expedites the proper management, especially in emergency settings.

The wide application of RNA sequencing in clinical practice has allowed the discovery of novel fusion genes, which have contributed to a refined molecular classification of rhabdomyosarcoma (RMS). Most fusions in RMS result in aberrant transcription factors, such as PAX3/7::FOXO1 in alveolar RMS (ARMS) and fusions involving VGLL2 or NCOA2 in infantile spindle cell RMS. However, recurrent fusions driving oncogenic kinase activation have not been reported in RMS. Triggered by an index case of an unclassified RMS (overlapping features between ARMS and sclerosing RMS) with a novel FGFR1::ANK1 fusion, we reviewed our molecular files for cases harboring FGFR1-related fusions. One additional case with an FGFR1::TACC1 fusion was identified in a tumor resembling embryonal RMS (ERMS) with anaplasia, but with no pathogenic variants in TP53 or DICER1 on germline testing. Both cases occurred in males, aged 7 and 24, and in the pelvis. The 2nd case also harbored additional alterations, including somatic TP53 and TET2 mutations. Two additional RMS cases (one unclassified, one ERMS) with FGFR1 overexpression but lacking FGFR1 fusions were identified by RNA sequencing. These two cases and the FGFR1::TACC1-positive case clustered together with the ERMS group by RNAseq. This is the first report of RMS harboring recurrent FGFR1 fusions. However, it remains unclear if FGFR1 fusions define a novel subset of RMS or alternatively, whether this alteration can sporadically drive the pathogenesis of known RMS subtypes, such as ERMS. Additional larger series with integrated genomic and epigenetic datasets are needed for better subclassification, as the resulting oncogenic kinase activation underscores the potential for targeted therapy.

PELVIS syndrome describes the constellation of perineal hemangioma, external genitalia malformations, lipomyelomeningocele, vesicorenal abnormalities, imperforate anus, and skin tag. A 2-month-old girl presented with infantile hemangioma on her perineum and genitalia with imperforate anus, rectovaginal fistula and perineal skin tag at birth. Under the impression of PELVIS syndrome, consequential spinal sonography was conducted and revealed an intrasacral meningocele without clinical neurologic deficit. The anorectal malformation was surgically corrected, she was taking oral propranolol for the cutaneous lesion, and she showed improvement and no complications.

An inflammatory myofibroblastic tumour (IMT) is an uncommon neoplasm composed of inflammatory cells and myofibroblasts in a fibrous stroma. They are mostly seen in the lungs and rarely involve the gastrointestinal tract. An 8-month-old infant presented with a history of lower abdominal lump for 2 months. Her CT scan confirmed a large, lobulated mass in the retroperitoneum arising from the pelvis. The mass was found to be arising from the sigmoid colon on laparotomy which was excised. Histopathology showed a cellular tumour composed of spindle cells and inflammatory lymphocytic infiltrate. Immunohistochemistry revealed positive staining for anaplastic lymphoma kinase and smooth muscle actin, confirming the diagnosis of IMT. The patient is doing well at her 6-month follow-up. Ours is the youngest case of sigmoid IMT among the only other series of eight cases reported in the literature indicating its rarity.

Most osteoarticular infections (OAI) occur via the hematogenous route, affect children under 5 years of age old, and include osteomyelitis, septic arthritis, osteoarthritis and spondylodiscitis. Early diagnosis and prompt treatment are needed to avoid complications. Children with suspected OAI should be hospitalized at the start of therapy. Surgical drainage is indicated in patients with septic arthritis or periosteal abscess. Staphylococcus aureus is implicated in OAI in children at all ages; Kingella kingae is a very common causative pathogen in children from 6 months to 4 years old. The French Pediatric Infectious Disease Group recommends empirical antibiotic therapy with appropriate coverage against methicillin-sensitive S. aureus (MSSA) with high doses (150 mg/kg/d) of intravenous cefazolin. In most children presenting uncomplicated OAI with favorable outcome (disappearance of fever and pain), short intravenous antibiotic therapy during 3 days can be followed by oral therapy. In the absence of bacteriological identification, oral relay is carried out with the amoxicillin/clavulanate combination (80 mg/kg/d of amoxicillin) or cefalexin (150 mg/kg/d). If the bacterial species is identified, antibiotic therapy will be adapted to antibiotic susceptibility. The minimum total duration of antibiotic therapy should be 14 days for septic arthritis, 3 weeks for osteomyelitis and 4-6 weeks for OAI of the pelvis, spondylodiscitis and more severe OAI, and those evolving slowly under treatment or with an underlying medical condition (neonate, infant under 3 months of old, immunocompromised patients). Treatment of spondylodiscitis and severe OAI requires systematic orthopedic advice.