Hydatid disease of the pelvis is a rare form of echinococcosis infection and seldom occurs in bilateral ureteric obstruction resulting in hydroureteronephrosis. A male patient in his 50s presented with a history of progressive abdominal distension and pain since two months. The ultrasonography revealed a large multiloculated cystic lesion in the pelvis, resulting in the compression of bilateral ureters and thus leading to bilateral hydroureteronephrosis. The case presents a rare yet clinically relevant manifestation of hydatid disease of the pelvis and points to the necessity to consider hydatid cyst along with the list of differentiating cysts of the pelvis causing obstructive uropathy.

Autosomal dominant polycystic kidney disease (ADPKD) arises from mutations in polycystin-1/PKD1 or polycystin-2/PKD2 that induce injury-repair pathways and dysregulate cAMP and Yes-associated protein (YAP) signaling to promote cyst growth. Cystic kidneys with elevated cAMP levels also develop in mouse embryos lacking the BicC family RNA-binding protein 1 (Bicc1). To prevent embryonic lethality, we flanked Bicc1 exon 4 with loxP sites for conditional knockout (cKO) in renal tubules using inducible Pax8-rtTA-driven Cre in adults, or distal segment-specific deletion in utero using Ksp-Cre. Whereas Bicc1-deficient adult kidneys formed relatively few cysts within six months, distal nephron-specific deletion induced aggressive PKD-like disease. Automated renal tubule and cyst quantification (ARTCyQ), a novel machine-learning pipeline to analyze immunofluorescent stainings, revealed increasing ambiguity in nephron segment identity and activation of ADPKD-related pathways, including YAP signaling. Accordingly, transcriptional profiling revealed overlap with PKD and injury-repair signatures, supporting a role for Bicc1 in polycystin signaling.

Background/Objectives: Birt-Hogg-Dubé (BHD) syndrome is a rare autosomal dominant disorder caused by germline pathogenic variants in the folliculin (FLCN) gene. Although it carries a substantial lifetime risk of renal cell carcinoma, its earliest manifestations are typically pulmonary cysts and spontaneous pneumothorax, which are frequently misclassified as primary spontaneous pneumothorax, resulting in diagnostic delay and inadequate oncological surveillance. We aimed to characterise the real-world phenotypic spectrum of BHD encountered in a respiratory referral setting. Methods: We retrospectively describe seven consecutive patients with genetically confirmed BHD syndrome diagnosed at our tertiary referral centre between 2022 and 2024. Demographic data, smoking history, FLCN variants, pneumothorax episodes, high-resolution computed tomography (HRCT) findings, pulmonary function tests and extrapulmonary neoplasms were collected. Reporting followed the PROCESS 2020 guideline. Results: Mean age at genetic diagnosis was 53.1 years (range 41-64). All seven patients had multiple thin-walled pulmonary cysts on HRCT, with the typical basal, subpleural and paramediastinal distribution; three had a pneumothorax history. Despite largely preserved spirometry-mean forced expiratory volume in 1 s (FEV1) of 82.4% predicted-the diffusing capacity of the lung for carbon monoxide (DLCO) was reduced in five patients (mean of 67.4% predicted) and was the most frequently affected functional parameter, although the overall functional picture was heterogeneous. Five patients had solid neoplasms (one renal, one colorectal, one thyroid/parathyroid, one ovarian, one lung adenocarcinoma). Conclusions: In this referral-based case series, pulmonary cysts were a constant finding and DLCO was the most frequently reduced functional parameter, although the functional picture varied across patients. These descriptive observations are hypothesis-generating and require prospective, controlled validation-including comparison with other diffuse cystic lung diseases-before any diagnostic algorithm can be proposed.

BACKGROUND Hydatid disease, caused by Echinococcus granulosus, is an endemic parasitic infection that predominantly affects the liver. Although slow-growing and asymptomatic, large hepatic cysts lead to catastrophic vascular complications, including inferior vena cava (IVC) thrombosis and pulmonary embolism (PE). Although rare, life-threatening events require prompt recognition and multidisciplinary management to optimize outcomes. CASE REPORT A 68-year-old woman with paroxysmal atrial fibrillation presented with right upper-quadrant pain, fever, and poor oral intake for several weeks. Examination revealed abdominal distension, hepatomegaly, and mottled, cold lower limbs. Laboratory findings showed severe metabolic acidosis and leukocytosis, indicating significant systemic involvement and possible sepsis. Computed tomography (CT) angiography demonstrated a pulmonary embolism, a giant (29×18 cm) right hepatic cyst exerting a mass effect, and extensive thrombosis extending from the infrarenal IVC to both external iliac veins. Echocardiography showed extrinsic cardiac compression without signs of tamponade but with functional compromise related to mass effect. Management included anticoagulation, albendazole, broad-spectrum antibiotics, vasopressors, and continuous renal replacement therapy. Ultrasound-guided percutaneous drainage of the cyst yielded 4 L of purulent fluid, with transient improvement in limb perfusion suggesting partial decompression of venous outflow obstruction. An IVC filter was inserted, but despite intensive therapy, the patient developed refractory shock and died due to progressive hemodynamic collapse and multiorgan failure. CONCLUSIONS Massive hepatic hydatid cysts can precipitate IVC thrombosis and PE through mechanical compression or infection-related inflammation. Early diagnosis, multidisciplinary coordination, and timely surgical or percutaneous decompression are vital to prevent death.

Renal hydatid cysts rarely occur in children. The kidney is the third most frequently affected organ, following the liver and lungs, and presents diverse clinical manifestations. This report describes a previously healthy 14-year-old girl whose mother underwent hepatic hydatid cyst surgery a year earlier. The girl reported three months of left-sided lumbar pain. Clinical examination revealed a palpable, non-tender left flank mass. Imaging revealed two cystic lesions in her left kidney. She received a partial pericystectomy and recovered uneventfully. The family was counseled on how to prevent Echinococcus. Subsequent screening detected a pulmonary hydatid cyst in her 9-year-old brother.

Heterotopic pancreas (HP) is a rare congenital anomaly characterized by pancreatic tissue lacking anatomical and vascular continuity with the orthotopic pancreas. Although usually asymptomatic and incidentally diagnosed, HP may rarely become clinically significant due to inflammation, ulceration, bleeding, obstruction, or gastrointestinal perforation. Systemic conditions such as amyloidosis, chronic kidney disease (CKD), and chronic hemodialysis may further increase gastrointestinal vulnerability through vascular fragility, impaired mucosal healing, and recurrent splanchnic hypoperfusion. We present the case of a patient with systemic amyloidosis and end-stage CKD on maintenance hemodialysis through a recently created brachial-basilic arteriovenous fistula who developed progressive gastrointestinal symptoms followed by acute abdomen. Initial manifestations included nausea and projectile vomiting one day after fistula creation, followed by progressive right upper quadrant abdominal pain radiating to the lumbar region, semiliquid bowel movements, dehydration, and hemodynamic instability. Imaging studies suggested a perforated viscus with intra-abdominal inflammatory changes. Emergency exploratory laparotomy revealed perforation at the antro-duodenal junction with diffuse fibrinous peritonitis and multiple cystic peritoneal lesions suspicious for malignant disease. Surgical management consisted of segmental gastroduodenal resection, extensive peritoneal lavage, targeted peritoneal biopsies, cholecystectomy, and appendectomy. Histopathological examination demonstrated heterotopic pancreatic tissue associated with ulceration and perforation. Immunohistochemistry of the peritoneal lesions showed positivity for WT1 and calretinin, consistent with benign peritoneal inclusion cysts. This case highlights an exceptionally rare cause of gastrointestinal perforation and underscores the importance of integrating clinical evolution, systemic comorbidities, intraoperative findings, pathology, and immunohistochemistry into surgical decision-making. The coexistence of amyloidosis, CKD, and hemodialysis-related hypoperfusion likely contributed synergistically to mucosal vulnerability and perforation.

There are various radiopharmaceuticals and hybrid imaging techniques for evaluating pediatric patients in the acute care setting. The focus of this article is on common nuclear medicine applications in pediatric acute care. Brain scintigraphy is an important ancillary test for evaluation of brain death/death by neurologic criteria when the clinical examination or apnea test cannot be safely or completely performed. Ventilation-perfusion scintigraphy is considered as a safe and useful test for suspected pulmonary embolism in hemodynamically stable children, especially when the chest radiograph is normal or near normal and radiation reduction is important. 99mTc-pertechnetate scintigraphy is stated to be the best noninvasive nuclear medicine test for detecting ectopic gastric mucosa in Meckel's diverticulum, whereas 99mTc-labeled red blood cell scintigraphy is useful for evaluating active or intermittent lower gastrointestinal bleeding from different causes. Hepatobiliary scintigraphy provides functional assessment of biliary excretion and is useful for evaluation of acute cholecystitis, choledochal cysts, and bile leaks. 99mTc-DMSA renal cortical scintigraphy is a sensitive method for detecting acute pyelonephritis and renal cortical scarring, while 99mTc-MAG3 renal scintigraphy is used to evaluate early and late complications of renal transplantation. Bone scintigraphy is considered as a valuable imaging modality for evaluation of osteomyelitis, occult fracture, stress injury, sickle cell related bone pain, and selected cases of suspected physical abuse, especially when whole body assessment is needed. 18F-FDG PET/CT has an increasing role in selected children with fever of unknown origin and inflammatory disorders. Moving forward, continued refinement of pediatric administered activities, wider use of SPECT/CT and PET-based imaging and updated pediatric-specific guidelines are expected to further improve the role of nuclear medicine in acute pediatric care.

The long-term renal implications of conditions leading to male reproductive surgeries remain unclear. This study evaluated the potential causal relationships between genetic liability to undergoing these surgeries and kidney diseases. Genetic variants associated with four surgery-related phenotypes-testicular hydrocele surgery, testicular or scrotal surgery, circumcision, and vasectomy-were selected as instrumental variables. Mendelian randomization, meta-analysis, and exploratory mediation analyses were used to assess associations with 20 kidney outcomes. Results showed genetic liability to testicular hydrocele surgery was associated with higher odds of chronic kidney disease, IgA nephropathy, glomerulonephritis, cystic kidney disease, tubulo-interstitial nephritis, and kidney injury, and with lower odds of benign kidney tumors and renal stones. Genetic liability to testicular or scrotal surgery was associated with increased odds of renal colic, gout, malformations of the renal pelvis or ureters, renal stones, and kidney infections. Genetic liability to circumcision was associated with higher odds of congenital obstructive malformations, hypertensive heart/renal disease, malignant kidney neoplasms, and increased kidney volume, and with lower odds of kidney cysts, benign tumors, and chronic renal failure. Genetic liability to vasectomy was linked to reduced odds of pyelonephritis and malignant kidney neoplasms. Mediation analyses suggested partial contributions of immune and metabolic traits. This study provides evidence that genetic liability to undergoing male reproductive system surgeries-reflecting the underlying biological or pathological indications-is associated with distinct patterns of kidney disease susceptibility. Findings suggest that individuals with underlying conditions predisposing them to testicular hydrocele or scrotal surgery may benefit from attention to long-term kidney health.

Renal cysts in autosomal dominant polycystic kidney disease (ADPKD) frequently harbor small intracystic epithelial proliferations that arise in continuity with the cyst lining and are distinct from other recognized proliferative lesions or well-defined renal tumors and lack a formal designation. We aim to provide the histomorphologic, immunohistochemical (IHC), and molecular characteristics of these lesions, determine their incidence, and employ the term papillary hyperplasia (PH), consistent with the recent International Society of Urological Pathology (ISUP) consensus meeting report on precursor lesions of the kidney. A multi-institutional retrospective study of nephrectomies affected by ADPKD was reviewed for PH, histomorphologic features, and clinicopathologic data. PH was defined by intracystic tufted or papillary epithelial proliferations composed of a single layer of bland cuboidal epithelial cells with minimal amphophilic to eosinophilic cytoplasm. IHC stains and molecular analysis using whole-genome sequencing were performed on a subset of cases. Eighty-five nephrectomies from 48 patients demonstrated PH in 88% (75/85) of kidneys. Predominant architectural patterns were tufting (97%), papillary (72%), hobnail (72%), and micropapillary (51%). All PH exhibited low-grade nuclei without atypia, with amphophilic (95%) and/or eosinophilic cytoplasm (63%). The most well-developed PH per case measured 0.3 by 3.1 mm (mean height by width) and occurred within small cysts with an average diameter of 3 mm. PH were positive for KRT7, GATA3, L1CAM, variably positive for AMACR, and negative for CA9 and showed no definitive molecular alterations. PH are common microscopic findings in kidneys affected by ADPKD. PH show a distinct combined histomorphologic, IHC, and molecular profile.

Pathogenic variants in the WDR72 gene are known to cause hypoplastic amelogenesis imperfecta (AI) and have recently been linked to distal renal tubular acidosis (dRTA). This case report highlights an unusual presentation of WDR72-associated dRTA with renal cysts. A 12-year-old boy presented with difficulty walking, lower limb deformities, and significant growth retardation. On examination, hypoplastic AI, rickets, and short stature were present. Biochemical investigations showed hypokalemia, hypophosphatemia, elevated alkaline phosphatase, and hypercalciuria. Imaging revealed medullary nephrocalcinosis and renal cysts. Clinical exome sequencing identified a homozygous pathogenic nonsense variant in WDR72 (NM_182758.4): c.2934G > A (p.Trp978Ter), consistent with autosomal recessive inheritance. He was diagnosed with dRTA and managed with potassium citrate and phosphate supplementation. Over two years, the patient showed improved growth velocity and reduced hypercalciuria, though nephrocalcinosis and renal cysts persisted. This case of WDR72-associated dRTA complicated by renal cyst formation is an underrecognized phenotype of this rare disorder. It further highlights that delayed diagnosis and prolonged, uncorrected tubulopathy may result in structural renal injury that is not fully reversible with treatment. Systematic renal evaluation, including biochemical assessment and renal ultrasonography, is strongly warranted in all children presenting with AI, particularly in the presence of concurrent growth failure, electrolyte disturbances, or rachitic changes, to facilitate early diagnosis and mitigate the risk of long-term renal sequelae.