Vessel-Guided Mesohepatectomy for Liver Partition and Staged Major Parenchyma-Sparing Hepatectomies with Super-Selective Portal Vein Embolization or Enhanced ALPPS to Achieve R0 Resection for Colorectal Liver Metastases at the Hepatocaval Confluence.

Background. R0 minor parenchyma-sparing hepatectomy (PSH) is feasible for colorectal liver metastases (CRLM) in contact with hepatic veins (HV) at hepatocaval confluence since HV can be reconstructed, but in the case of contact with the first-order glissonean pedicle (GP), major hepatectomy is mandatory. To pursue an R0 parenchyma-sparing policy, we proposed vessel-guided mesohepatectomy for liver partition (MLP) and eventually combination with liver augmentation techniques for staged major PSH. Methods. We analyzed 15 consecutive vessel-guided MLPs for CRLM at the hepatocaval confluence. Patients had a median of 11 (range: 0-67) lesions with a median diameter of 3.5 cm (range: 0.0-8.0), bilateral in 73% of cases. Results. Grade IIIb or more complications occurred in 13%, median hospital stay was 14 (range: 6-62) days, 90-day mortality was 0%. After a median follow-up of 17.5 months, 1-year OS and RFS were 92% and 62%. In nine (64%) patients, MLP was combined with portal vein embolization (PVE) or ALPPS to perform staged R0 major PSH. Future liver remnant (FLR) volume increased from a median of 15% (range: 7-20%) up to 41% (range: 37-69%). Super-selective PVE was performed in three (33%) patients and enhanced ALPPS (e-ALPPS) in six (66%). In two e-ALPPS an intermediate stage of deportalized liver PSH was necessary to achieve adequate FLR volume. Conclusions. Vessel-guided MLP may transform the liver in a paired organ. In selected cases of multiple bilobar CRLM, to guarantee oncological radicality (R0), major PSH is feasible combining advanced surgical parenchyma sparing with liver augmentation techniques when FLR volume is insufficient.

Development of associational fiber tracts in fetal human brain: a cadaveric laboratory investigation.

The advent of diffusion tensor imaging (DTI) in addition to cadaveric brain dissection allowed a comprehensive description of an adult human brain. Nonetheless, the knowledge of the development of the internal architecture of the brain is mostly incomplete. Our study aimed to provide a description of the anatomical variations of the major associational bundles, among fetal and early post-natal periods. Seventeen formalin-fixed fetal human brains were enrolled for sulci analysis, and 13 specimens were dissected under the operating microscope, using Klingler's technique. Although fronto-temporal connections could be observed in all stages of development, a distinction between the uncinate fascicle, and the inferior fronto-occipital fascicle was clear starting from the early preterm period (25-35 post-conceptional week). Similarly, we were consistently able to isolate the periatrial white matter that forms the sagittal stratum (SS), with no clear distinction among SS layers. Arcuate fascicle and superior longitudinal fascicle were isolated only at the late stage of development without a reliable description of their entire course. The results of our study demonstrated that, although white matter is mostly unmyelinated among fetal human brains, cadaveric dissection can be performed with consistent results. Furthermore, the stepwise development of the associational fiber tracts strengthens the hypothesis that anatomy and function run in parallel, and higher is the cognitive functions subserved by an anatomical structure, later the development of the fascicle. Further histological-anatomical-DWI investigations are required to appraise and explore this topic.

Upper transversal hepatectomy with double hepatic vein resection and reconstruction to treat colorectal cancer liver metastases at the hepatocaval confluence: a strategy to achieve R0 liver-sparing resection.

BACKGROUND: Repeated hepatectomies in the therapeutic route of patients with colorectal liver metastases (CRLM) may improve their long term survival. Hepatic vein (HV) resection and reconstruction allows parenchyma-sparing hepatectomy (PSH) and R0 resections for CRLM in contact with one HV. We aimed at verifying the feasibility of PSH with double HV resection and direct reconstruction for CRLM in contact with two HVs at the hepatocaval confluence. METHODS: Out of 106 consecutive PSH performed for CRLM deep-located in segments I-IVa-VII-VIII, four (3.7%) PSH were performed with resection of CRLM en bloc with two adjacent HVs which were both reconstructed with double direct HV anastomosis: 3 cases between right-HV and middle-HV and 1 case between middle-HV and left-HV. Two patients had previously undergone liver resection. Three patients had one single lesion and one had 5 CRLMs. RESULTS: Median size of CRLMs in contact with HVs was 25 mm (range 22-30 mm). At histological examination, all resections were R0 except one R1-vascular (detachment from glissonean pedicle): in all cases at least one HV and in 1 case both HVs were infiltrated by the tumor cells. After median follow-up of 18 (range 3.5-41.2) months, all HVs were patent. All patients were alive and in good general conditions, and 3 patients were disease free (one of them following a liver re-resection). One patient experienced a grade IIIa complication. Median hospital-stay was 11 (range 9-13) days. CONCLUSION: In patients with CRLMs involving two adjacent HVs at the hepatocaval confluence, liver resection with double HV resection and direct reconstruction is feasible and may be considered to guarantee oncological radicality (R0) and spare health parenchyma.

Incidentally discovered Meckel's diverticulum: should I stay or should I go?

BACKGROUND: The aim of this study was to assess the indication for surgical treatment of incidentally discovered Meckel's diverticulum (MD) on the basis of clinical and histological features. METHODS: The charts of patients undergoing surgery for MD were analysed. Two groups were identified: (1) patients who had incidentally discovered MD resected (incidental MD, IMD) and (2) patients who received first-line surgery for a complicated MD (CMD). Demographics and intraoperative and post-operative outcomes were compared. Histological findings were also analysed and compared. RESULTS: Sixty-five patients were included in the study. IMD was observed in 39 patients (60%), while CMD was observed in 26 (40%). Male gender was significantly more frequent in CMD (P = 0.020), and mean age was significantly higher in IMD (P = 0.025). Body mass index and the American Society of Anesthesiologists score >2 were similar in both groups. Laparoscopy was carried out in 36% of IMD and in 50% of CMD patients (P = 0.309). A tangential resection was performed in 92% of IMD and 73% of CMD patients (P = 0.07). No complications related to diverticular resection were found in IMD, while they occurred in 8% of CMD patients (P = 0.931). Meanly, diverticula were longer when complicated (P = 0.001). CMD showed significant histological differences and more frequent gastric ectopic mucosa (P = 0.039). A malignant tumour was incidentally found in IMD. CONCLUSION: As surgery is mandatory in CMD, the optimal management of IMD remains uncertain. Mucosal abnormalities may favour complications, but these cannot be identified before excision. Stapled diverticulectomy is safe and effective. A surgical approach to IMD may prevent complications at a very low cost.

Expression of calcium-binding proteins and selected neuropeptides in the human, chimpanzee, and crab-eating macaque claustrum.

The claustrum is present in all mammalian species examined so far and its morphology, chemoarchitecture, physiology, phylogenesis and ontogenesis are still a matter of debate. Several morphologically distinct types of immunostained cells were described in different mammalian species. To date, a comparative study on the neurochemical organization of the human and non-human primates claustrum has not been fully described yet, partially due to technical reasons linked to the postmortem sampling interval. The present study analyze the localization and morphology of neurons expressing parvalbumin (PV), calretinin (CR), NPY, and somatostatin (SOM) in the claustrum of man (# 5), chimpanzee (# 1) and crab-eating monkey (# 3). Immunoreactivity for the used markers was observed in neuronal cell bodies and processes distributed throughout the anterior-posterior extent of human, chimpanzee and macaque claustrum. Both CR- and PV-immunoreactive (ir) neurons were mostly localized in the central and ventral region of the claustrum of the three species while SOM- and NPY-ir neurons seemed to be equally distributed throughout the ventral-dorsal extent. In the chimpanzee claustrum SOM-ir elements were not observed. No co-localization of PV with CR was found, thus suggesting the existence of two non-overlapping populations of PV and CR-ir interneurons. The expression of most proteins (CR, PV, NPY), was similar in all species. The only exception was the absence of SOM-ir elements in the claustrum of the chimpanzee, likely due to species specific variability. Our data suggest a possible common structural organization shared with the adjacent insular region, a further element that emphasizes a possible common ontogeny of the claustrum and the neocortex.

Molecular characterization of 54 cases of false-negative fine-needle aspiration among 1347 papillary thyroid carcinomas.

BACKGROUND: Fine-needle aspiration (FNA) has been widely accepted as the most crucial step in the preoperative assessment of thyroid nodules, but the false-negative rates are generally reported to be between 3.6% and 10.2%. To lower the overall incidence of this false-negative testing, new reporting systems encourage the molecular testing of thyroid nodules. However, to the authors' knowledge, the role of molecular testing in false-negative FNA has not yet been evaluated. METHODS: In total, 1347 consecutive papillary thyroid carcinomas (PTCs) with both cytological and histological diagnoses were collected from the same center. A blinded revision of the false-negative cases was performed. An analysis of the BRAF and Ras genes in the false-negative cases was then performed. RESULTS: The false-negative rate at the time of primary FNA diagnosis was 4.8% (65 of 1347 cases). False-negative cases were 15 follicular variant PTCs, 2 classical variant, and 1 solid variant that lacked peculiar PTC cytomorphological features. Adequate cellular material for molecular analysis was available only in 54 of the 65 false-negative cases. Mutations were found in 6 cases (11%), and Ras alterations were present in 16 cases (29.6%). The addition of molecular analysis decreased the false-negative rate to 0.4% (5 of 1347 cases). CONCLUSIONS: The results of the current study confirm the feasibility of BRAF and Ras analysis in routine FNA. However, when the false-negative FNA rate is low, the cost-benefit analysis of the detection of BRAF and Ras mutations should be carefully evaluated. Consequently, the authors suggest that preoperative molecular assessment could be helpful for benign nodules, but only in the presence of clinical suspicion of malignancy.

Glomus tumor of the shoulder: A case report and review of the literature.

Glomus tumors are benign neoplasms that arise from neuromyoarterial glomus bodies, with clinical manifestations that include acute pain, cold intolerance and tenderness. Glomus tumors may occur anywhere in the skin, soft tissue or gastrointestinal tract, but are most frequently encountered in the nail bed of the hands. The present study reports the case of a 30-year-old female with a history of shoulder pain caused by a cystic neoformation. Following surgery, a microscopic examination revealed nests of small cells of a rounded and regular shape. The tumor cells exhibited positive expression for CD34 and smooth muscle actin. This study supports and confirms the fact that a glomus tumor is a benign neoplasm that may occur in multiple locations. Therefore, the significance of a histological and immunohistochemical approach for a correct characterization of this lesion is required.

Topography of Gng2- and NetrinG2-expression suggests an insular origin of the human claustrum.

The claustrum has been described in the forebrain of all mammals studied so far. It has been suggested that the claustrum plays a role in the integration of multisensory information: however, its detailed structure and function remain enigmatic. The human claustrum is a thin, irregular, sheet of grey matter located between the inner surface of the insular cortex and the outer surface of the putamen. Recently, the G-protein gamma2 subunit (Gng2) was proposed as a specific claustrum marker in the rat, and used to better delineate its anatomical boundaries and connections. Additional claustral markers proposed in mammals include Netrin-G2 in the monkey and latexin in the cat. Here we report the expression and distribution of Gng2 and Netrin-G2 in human post-mortem samples of the claustrum and adjacent structures. Gng2 immunoreactivity was detected in the neuropil of the claustrum and of the insular cortex but not in the putamen. A faint labelling was present also in the external and extreme capsules. Double-labelling experiments indicate that Gng2 is also expressed in glial cells. Netrin-G2 labelling was seen in neuronal cell bodies throughout the claustrum and the insular cortex but not in the medially adjacent putamen. No latexin immunoreactive element was detected in the claustrum or adjacent structures. Our results confirm that both the Gng2 and the Netrin-G2 proteins show an affinity to the claustrum and related formations also in the human brain. The presence of Gng2 and Netrin-G2 immunoreactive elements in the insular cortex, but not in the putamen, suggests a possible common ontogeny of the claustrum and insula.