[Giant lipomas or retroperitoneal liposarcomas? Controversies in their diagnosis and treatment]. / ¿Lipoma gigante o liposarcoma retroperitoneal? Controversias en su diagnóstico y tratamiento.

BACKGROUND: Retroperitoneal lipomas are extremely rare tumors that must be differentiated from well-differentiated liposarcomas (WD-LPS). OBJECTIVES: To summarize the evidence about giant retroperitoneal lipomas or liposarcomas; and to elaborate recommendations for their management. DATA SOURCES: A systematic literature search from January 1985 to December 2019 and a review of our own cases was performed. RESULTS: Our series comprises four patients, two females and two males. The diagnosis was incidental in two cases. The medium size was 26 cm, being two cases located exclusively in the retroperitoneum, one in the inguinal region and one in the buttock via pelvic space. All cases were surgically removed being confirmed the initial diagnosis of retroperitoneal lipomas in two cases, as the rest two cases were classified as WD_LPS after MDM2/CDK4 genetic analysis. The review of the available literature plus our own cases revealed 30 cases, of which 58% were woman. Only two cases were asymptomatic. The main symptom was abdominal mass (53%) followed by abdominal pain (40,6%). The median size of the lesions was 24,9 cm with a median weight of 4.576,3 g. All cases were surgically removed, being necessary to remove contiguous organs in only four cases (12,5%). CONCLUSIONS: Retroperitoneal lipoma is a rare tumor which must be differentiated from WD-LPS. This is a very difficult task, being necessary to determinate MDM2 status (by FISH or MLPA), present in liposarcoma but not in lipomas, for its correct diagnosis. The treatment must be based on a complete surgical resection with negative margins.

Novel Mutation (Gly212Val) in the PS2 Gene Associated with Early-Onset Familial Alzheimer's Disease.

Mutations in the presenilin 2 gene (PS2) are an extremely rare cause of early-onset autosomal dominant Alzheimer's disease (AD), accounting for only 5% of these families. These cases represent a particular model of AD, and the scarcity of reports on their clinical phenotypes makes them of great interest. We report a family with early-onset autosomal dominant AD in four members, where the two living siblings were found to carry the novel PS2 mutation Gly212Val (exon 7, transmembrane domain IV) with highly predicted pathogenicity. Age at onset ranged from 60 to 65 years and three of the cases died between ages 74 and 76 years. Clinical phenotype was quite homogeneous among affected members of the family, and overall features, including cognitive decline, tau/p-tau and amyloid-ß cerebrospinal fluid markers, neuroimaging, and neuropathology were consistent with typical AD. Lewy bodies were present but restricted to the amygdala.