Long-term outcome after laparoscopic fenestration of simple liver cysts

BACKGROUND: Simple liver cysts (LCs) represent the most common benign liver disease, with a prevalence of 3-5%. Laparoscopic fenestration is considered the best treatment for symptomatic LCs, but few studies have analyzed the rate or type of recurrence during a long-term follow-up period (>5 years). METHODS: Between January 2000 and December 2010, 47 patients underwent laparoscopic fenestration for simple LCs. The indications were symptoms for 42 patients and an uncertain diagnosis for five patients. The follow-up assessment consisted of regular patient evaluations, with results of laboratory data and liver ultrasound. RESULTS: Conversion to laparotomy was not necessary in any case. The postoperative mortality and morbidity rates were nil. The mean follow-up period was 67 months (range 12-142 months), and 26 patients (55.3%) had a follow-up period longer than 5 years. During the follow-up period, 40 patients (85.1%) did not present with any type of recurrence. The overall recurrence rate was 14.9% (seven patients) based on five patients (10.6%) with radiologic asymptomatic recurrences detected by ultrasound or computed tomography (CT) scan and two patients (4.3%) with clinicoradiologic symptomatic recurrences. Both symptomatic recurrences involved LCs located in the right posterior segments. CONCLUSIONS: Laparoscopic fenestration provided complete relief of symptoms for about 95% of patients with simple LCs. Recurrence after surgery was experienced by 14.9% of the patients, but only in 4.3% (two patients) was this recurrence symptomatic requiring a second treatment. The site of recurrence was more frequently in the right posterior segments. Laparoscopic fenestration of symptomatic LCs can be considered a safe and effective procedure that can yield good long-term results

Planarian Stem Cell Heterogeneity

Planarian (Platyhelminthes, Triclads) are free-living flatworms endowed with extraordinary regenerative capabilities, i.e., the ability to rebuild any missing body parts also from small fragments. Planarian regenerative capabilities fascinated scientific community since early 1800, including high-standing scientists such as J.T. Morgan and C. M. Child. Today, it is known that planarian regeneration is due to the presence of a wide population of stem cells, the so-called neoblasts. However, the understanding of the nature of cells orchestrating planarian regeneration was a long journey, and several questions still remain unanswered. In this chapter, beginning from the definition of the classical concept of neoblast, we review progressive discoveries that have brought to the modern view of these cells as a highly heterogeneous population of stem cells including pluripotent stem cells and undifferentiated populations of committed progenies

Stem Cells, Patterning and Regeneration in Planarians: Self-Organization at the Organismal Scale.

The establishment of size and shape remains a fundamental challenge in biological research that planarian flatworms uniquely epitomize. Planarians can regenerate complete and perfectly proportioned animals from tiny and arbitrarily shaped tissue pieces; they continuously renew all organismal cell types from abundant pluripotent stem cells, yet maintain shape and anatomy in the face of constant turnover; they grow when feeding and literally degrow when starving, while scaling form and function over as much as a 40-fold range in body length or an 800-fold change in total cell numbers. This review provides a broad overview of the current understanding of the planarian stem cell system, the mechanisms that pattern the planarian body plan and how the interplay between patterning signals and cell fate choices orchestrates regeneration. What emerges is a conceptual framework for the maintenance and regeneration of the planarian body plan on basis of the interplay between pluripotent stem cells and self-organizing patterns and further, the general utility of planarians as model system for the mechanistic basis of size and shape