Case Report: Robotically Assisted Excision of Cystic Tumor Located in a Difficult to Access Area in the Liver

Introduction: Cystic liver lesions may be benign cysts, parasitic infestations, or malignant tumors requiring surgical resection. Hilar location and relation to major vasculature present challenges in conventional surgical access and resection.Materials and Methods: We describe totally robotic excision of a cystadenoma in a 55-year-old woman without complication. Time points in the accompanying video (https://youtu.be/Tn_QPgpSHA4) are embedded within the text.Results: Advantages of the robotic technique lie in overcoming the natural restriction of conventional laparoscopic instruments, easier repair, and control of intraoperative vascular injuries using EndoWrist® instruments, ergonomic dissection close to major vasculature and reduced intraoperative blood loss as dissection is easier.Discussion: Indications for robotic surgery included the large size of the cystic lesion, its intrahepatic location, and compression of the inferior vena cava (IVC) and right and middle hepatic veins. Had robotic removal of the lesion not been feasible, the entire lobe of the liver would have required resection.

Liver metastasis mimicking a liver cyst of a thymoma in a 38-year-old immunocompromised patient

Cystic liver lesions (CLL) are common and, in the majority of cases, benign. However, the range of differential diagnoses of CLL is wide. A combination of medical history, blood test results, and imaging can help find the correct diagnosis. We report the case of a 38-year-old immunocompromised female patient with a history of thymectomy and postoperative radiation 3 years prior due to thymoma. Subsequently, the patient was referred to our department for clarification of a cystic liver lesion. During short-term follow-up, the lesion increased in size, and due to the contrast agent behavior in the ultrasound and MRI examination, the suspicion of a biliary cystadenocarcinoma was considered.Furthermore, imaging showed several subcentimetric liver lesions of unknown dignity. Finally, pericystectomy and atypical partial liver resection was performed. Histology revealed a cystic metastasis of the malignant B3 thymoma and a cavernous hemangioma. Liver metastases of a thymoma are rare, and this is the first case of a cystic liver metastasis of a thymoma. The presented case illustrates that in the management of CLLs beside imaging techniques, the medical history with previous conditions should be considered, especially in past malignancies.

Nonsense-associated alternative splicing as a putative reno-protective mechanism in Pkhd1cyli/Pkhd1cyli mutant mice

Autosomal recessive polycystic kidney disease (ARPKD) is a hereditary hepato-renal fibrocystic disorder and a significant genetic cause of childhood morbidity and mortality. Mutations in the Polycystic Kidney and Hepatic Disease 1 (PKHD1) gene cause all typical forms of ARPKD. Several mouse strains carrying diverse genetically engineered disruptions in the orthologous Pkhd1 gene have been generated. The current study describes a novel spontaneous mouse recessive mutation causing a cystic liver phenotype resembling the hepato-biliary disease characteristic of human ARPKD. Here we describe mapping of the cystic liver mutation to the Pkhd1 interval on Chromosome 1 and identification of a frameshift mutation within Pkhd1 exon 48 predicted to result in premature translation termination. Mice homozygous for the new mutation, symbollzed Pkhd1cyli, lack renal pathology, consistent with previously generated Pkhd1 mouse mutants that fail to recapitulate human kidney disease. We have identified a profile of alternatively spliced Pkhd1 renal transcripts that are distinct in normal versus mutant mice. The Pkhd1 transcript profile in mutant kidneys is consistent with predicted outcomes of nonsense-associated alternative splicing (NAS) and nonsense mediated decay (NMD). Overall levels of Pkhd1 transcripts in mutant mouse kidneys were reduced compared to kidneys of normal mice, and Pkhd1 encoded protein in mutant kidneys was undetectable by immunoblotting. We suggest that in Pkhd1cyli/Pkhd1cyli (cyli) mice, mutation-promoted Pkhd1 alternative splicing in the kidney yields transcripts encoding low-abundance protein isoforms lacking exon 48 encoded amino acid sequences that are sufficiently functional so as to attenuate expression of a renal cystic disease phenotype.

Robotic enucleation of a biliary adenofibroma

A 69-year-old man was referred to the hepatobiliary surgeons for mild enlargement of an asymptomatic cystic liver lesion found on routine screening in 2017 that measured 3.7×3.6×4.3 cm. Work-up with MRI revealed a complex multilocular cyst that had enlarged to 6.6×5.5×4.6 cm. Other work-up was unremarkable. He had a Eastern Cooperative Oncology Group score of 1; therefore, a surgical excision was planned due to the possibility for malignancy. A robotic approach with enucleation of the lesion was undertaken, with plans for return for a wider resection if pathological examination revealed malignancy. The lesion was noted to be a biliary adenofibroma, an exceptionally rare lesion that is thought to be benign, but requires excision due to potential malignant degeneration. The patient was discharged home the following day and has had minimal pain in his postoperative course.

Ductal Plate Malformations in Captive Snakes

Ductal plate malformations are abnormalities in the liver that arise from inappropriate or incomplete remodeling of the embryologic ductal plate. Various types of ductal plate malformations are reported in the human and veterinary literature, most commonly affecting domestic mammalian species but also fish. We investigated the occurrence and described the histopathologic features of ductal plate malformations in captive snakes. Malformations were identified in 18 snakes: 10 colubrids, 6 vipers, and 2 boids. There was no sex predilection, and the mean age was 17 years. The majority of lesions were incidental with most snakes having one or more comorbidities, most commonly neoplasia or systemic inflammation, that resulted in natural death or euthanasia. Ductal plate malformations in all livers were broadly characterized by a well-demarcated nodule of irregular bile ducts embedded within a varying amount of fibrous stroma. Malformations were further categorized based on the amount of fibrous stroma and dilation of the bile ducts as von Meyenburg complexes, cystic liver disease, and/or an intermediate hybrid subtype representative of cysts arising within von Meyenburg complexes. Histochemical and immunohistochemical staining, including Gomori’s trichome and pan-cytokeratin, respectively, were applied on select cases to confirm histologic features. Malignant transformation was not identified within this population.

The Cystic Hepatic Mesenchymal Hamartoma in an Adult Mistaken for Hydatid Disease: Case Report

: Hydatid cyst is one of the predominantly cystic liver lesions and is also a zoonotic disease that is highly endemic in the Mediterranean region. This condition has extensive differential diagnoses, such as hepatic mesenchymal hamartoma, a rare benign hepatic tumor, which commonly occurs in infants and children, and is extremely rare in adults. Its imaging findings vary from a cystic tumor to a solid mass occupying one or both lobes of the liver. We report an unusual case of a purely cystic mesenchymal hamartoma of the liver in a 60-year-old female patient. The patient had been treated with albendazole for several years; however, the final histopathology revealed mesenchymal hamartoma.