PROX1 is a gene that encodes a protein that may play a key role in the development of the lymphatic system. This report describes impaired lymphatic drainage, with non-immune hydrops fetalis, congenital bilateral chylothorax, chylous ascites, and the need for peritoneal dialysis in a preterm neonate born at 32 weeks of gestation. The child died at about seven months of life. Clinical Exome Sequencing revealed the novel heterozygous variant c.502C > T in the PROX1 gene, which determines the change p.Arg168Trp at the protein level. This de novo missense variant was not detected in the analyzed parental DNA samples and has not been previously described in the literature. Although the identified PROX1 variant represents a biologically plausible contributor to the phenotype, causality cannot currently be established, and additional environmental or maternal factors cannot be excluded. Identifying this variant in affected individuals can have implications for perinatal and postnatal management and genetic counseling. To the best of our knowledge, this is the first case reported of a child carrier of a PROX1 variant with hydrops fetalis. PROX1 screening could be requested in prenatal diagnosis of hydrops fetalis and included in Next-Generation DNA Sequencing panels.

Central conducting lymphatic anomaly (CCLA) is a devastating disorder where precision medicine can be lifesaving. Diagnosing CCLA is challenging due to its broad spectrum of symptoms, including nonimmune fetal hydrops, chylothorax, chylous ascites, or lymphedema. For that reason, genetic diagnosis is essential to uncover new genes and variants causing this debilitating disease. A patient with complex congenital heart disease presented with post-operative refractory chylothorax. Lymphatic imaging demonstrated abnormal intercostal lymphatic perfusion consistent with CCLA and suggestive of a RASopathy, a group of genetic disorders characterized by dysregulated RAS-MAPK signaling. Genetic testing showed a variant of uncertain significance (p.(Ala308Val)) in SHOC2, a scaffolding protein that regulates RAS-MAPK signaling but has not yet been described in CCLA. Trametinib, a MEK1/2 inhibitor, was trialed without improvement. A conversion/extension assay was used to evaluate pathogenicity of the VUS compared to a known pathogenic variant. Zebrafish transiently expressing the wild type human SHOC2 protein or SHOC2 p.(Ala308Val) protein in the developing lymphatic and venous endothelium were used to evaluate the effect on the vasculature. Western blot was used to explore the underlying molecular mechanisms. Major to minor axis ratio was significantly increased in developing embryos injected with SHOC2 r.923c>u mRNA, indicating pathogenicity through dysregulation of MAPK/mTOR signaling. Zebrafish transiently expressing SHOC2 p.(Ala308Val) in the lymphovenous endothelium developed pericardial edema and cystic malformations of the caudal plexus and dilation of the thoracic duct. In concordance with the lack of clinical response to trametinib, immunoblot results indicate that SHOC2 p.(Ala308Val) may be inducing lymphatic malformations through non-canonical mTOR signaling rather than dysregulated RAS-MAPK signaling. SHOC2 is a novel cause of central conducting lymphatic anomaly. Future research should investigate the cellular and molecular mechanisms as well as therapeutics.

A 34-year-old female underwent robotic-assisted laparoscopic sleeve gastrectomy and was readmitted with large-volume chylous ascites. Initial non-operative management with aspiration and drainage was attempted but failed, leading to reaccumulation. This necessitated re-operation. Chyloperitoneum after sleeve gastrectomy is rare.

Primary effusion lymphoma (PE) is a rare form of non-Hodgkin lymphoma characterized by malignant lymphatic effusion in the pleural cavity. Non-traumatic chylothorax is usually caused by lymphomas with a discrete lymph node mass. Our report presents a case where chylothorax and chylous ascites were clinical presentation of primary effusion lymphoma (PEL), a rare entity that does not show the typical presence of an identifiable malignant mass. Managing PEL complicated by chylothorax is generally more challenging and has a poor prognosis, as illustrated by a patient in this case who died weeks after diagnosis.

We describe a case of refractory chylous ascites (RCA) successfully managed with a Denver shunt (DS) after conversion surgery for unresectable locally advanced pancreatic cancer. A 55-year-old woman developed RCA 6 months after distal pancreatectomy with celiac axis and portal vein resection. Conservative therapy, lymphangiography, and repeated paracentesis were ineffective. After confirming negative cytology, culture, and endotoxin tests, DS placement on postoperative day 425 resulted in rapid resolution of ascites, accompanied by improvement in body weight and hypoalbuminemia. No early major complications were observed after DS placement, and she was discharged safely. Although the shunt was removed 29 months later because of internal jugular vein thrombosis, no reaccumulation of ascites was observed thereafter. The patient remains alive without reaccumulation of ascites or tumor recurrence 60 months after curative resection. Although careful patient selection is essential because of potential complications, DS may serve as an effective salvage option for postoperative RCA when conservative approaches fail.

A 4-month-old female presented with progressive abdominal distention and feeding difficulties. Diagnostic laparoscopy with peritoneal drainage yielded 970 mL of milky ascites. Fluid analysis confirmed chylous ascites (triglyceride level, 3177 mg/dL; lymphocyte predominance, 94.8%) with negative culture and cytology results. Contrast-enhanced abdominal computed tomography revealed massive ascites without intra-abdominal lesions or significant lymphadenopathy. Despite conservative therapy and continuous high-output drainage (approximately 500 mL/day), the leak persisted. Planar lymphoscintigraphy with technetium-99m radiotracer injected subcutaneously into the dorsum of both feet confirmed lymphatic leakage into the ascites and provided regional guidance regarding the suspected source; however, no discrete focal hotspots were identified. Based on these scintigraphic findings, intraoperative near-infrared fluorescence lymphography using indocyanine green was performed the following day, enabling real-time visualization of active leakage and facilitating targeted laparoscopic treatment. Targeted electrocautery ablation markedly reduced leakage on real-time fluorescence imaging, and a fibrin sealant was subsequently applied. The patient ultimately achieved full oral feeding and showed no recurrence of ascites at the 2-year follow-up. This case illustrates a practical sequential imaging approach for refractory pediatric chylous ascites: lymphoscintigraphy for functional confirmation and regional guidance, followed by intraoperative indocyanine green fluorescence for focal confirmation and targeted treatment.

This presentation highlights a series of challenging reconstructive microsurgery cases encountered over the past 45 years. Selected cases from a collection of 500 unusual scenarios demonstrate innovative techniques developed to address complex reconstructive problems, aiming to stimulate discussion and further advancements in the field. These include refinements in microvascular anastomosis, novel approaches to esophageal reconstruction, treatment for intractable chylous ascites, techniques for small vessel anastomosis, solutions for vessel-depleted necks, and strategies for managing complications.

The occurrence of isolated (without accompanying chylothorax) chylous ascites after a VATS-esophagectomy is never documented in literature yet. We present a case of a 64-year-old patient who underwent a VATS esophagectomy for carcinoma esophagus and developed such a complication. We usually clip the thoracic duct in mediastinum intraoperatively. Therefore, the leak was unlikely to resolve conservatively as the distal passage of lymph was blocked and the leak site was under constant retrograde pressure. Hence, it was essential to intervene quickly to prevent nutritional deficits in patients by prolonging the conservative trial. We identified the source of the leak at the cisterna chyli through lymphangiography. After evaluating the situation, we decided to embolize the cisterna chyli under interventional radiology (IR) guidance. As the cases reported for cisterna chyli direct embolization are none in literature, this opens newer arenas in interventional radiology for such specific case management.

Chylous ascites (CA) is the accumulation of chylous lymphatic fluid within the abdominal cavity, usually resulting from laceration of the cisterna chyli or one of its major tributaries during retroperitoneal surgery. If left untreated, CA may become life-threatening. Current treatment recommendations favor a stepwise approach, beginning with conservative measures, followed by percutaneous interventions and, in refractory cases, surgical shunting procedures. Conservative management typically consists of dietary restriction of long-chain triglycerides, escalation to total parenteral nutrition (TPN), and adjunctive pharmacotherapy with somatostatin analogues. In most reported cases, these measures result in cessation of chylous leakage within several days. We report a case of CA after robotic-assisted retroperitoneal lymph node dissection (RPLND) in a 35-year-old male with testicular seminoma. Conservative management included paracentesis with drain insertion, TPN, and pharmacotherapy with octreotide. Ascitic fluid analysis confirmed CA with a triglyceride level of 420 mg/dL. Because chylous leakage did not cease after 60 days of hospital-based management, home-based TPN via a central venous port was initiated. Chylous leakage finally resolved after 80 days of conservative treatment. One year later, the patient remained well and had experienced no recurrence of either CA or seminoma. This case demonstrates that conservative treatment of CA may occasionally require a prolonged course and considerable patience from both the patient and the treating team.

Chyloperitoneum is a rare cause of ascites that results from the leakage of lipid-rich lymph into the abdominal cavity. Numerous etiologies can cause chylous ascites, with the most common causes being malignancy, cirrhosis, infection, and post-procedural lymphatic duct injury in adults. We describe a case of delayed chylous ascites formation after a pancreaticoduodenectomy (Whipple) procedure with lymphocele formation and slow leakage into the peritoneal cavity. Prompt recognition and diagnosis are paramount given the high mortality rate, and the management of this condition includes treating the underlying cause, symptom management, nutritional modification, and, in select cases, surgical interventions such as embolization.