Lobe Size Research Articles

1:30 PM Abstract No. 196 - Baseline left portal vein and left liver lobe size predicts hypertrophy of the left liver lobe after right portal vein embolization

Purpose Postoperative liver failure is a concern for patients who undergo partial hepatectomy for malignant liver lesions. Selective portal vein embolization (PVE) aims to increase the volume of the future liver remnant prior to resection. Hypertrophy of the non-malignant segments of liver following PVE is variable. Our objective was to determine whether baseline portal vein and liver size assessed on computed tomography (CT) can predict the degree of hypertrophy of the liver lobe following PVE. Materials and Methods A retrospective cohort study of adult patients who underwent right PVE prior to partial hepatectomy at a single university hospital was undertaken. Patients who had prior resections, prior embolization, had left portal vein or bilateral selective embolization were excluded. Patients were identified from the liver cancer database and PACS. All patients had a CT scan before and after PVE. The cross-sectional area of the main and left portal veins on pre and post-embolization CT were assessed within 1cm of the bifurcation. Volumetric measurements of the left liver lobe on all pre and post-embolization scans was performed. The left lobe was defined as segments 1, 2, 3, 4a and 4b. Data was analysed by linear regression and is expressed as mean (SD) or as stated. Results Fifty-four patients who met our inclusion criteria underwent first time PVE between 2004 and 2011. Fifty-one (94%) patients had colorectal metastases and the mean age of patients was 61 (10) years. The mean time from baseline CT to PVE was 55 (40.5) days and from PVE to post-embolisation CT was 27 (15.5) days. Baseline left portal vein and left liver lobe size were the only significant predictors of post PVE left liver lobe hypertrophy. Every mm 2 increase in baseline left portal vein diameter predicted a 2 cm 3 increase in post PVE left liver lobe size (B = 2.02) (SE: 0.82, p = 0.017). Conversely every cm 3 increase in baseline left liver lobe size predicted a 0.05% reduction in percent increase of left liver lobe size post PVE (B = −0.05) (SE: 0.02, p = 0.002). Conclusion Baseline left portal vein and left liver lobe size predicts post PVE left lobe size in this small cohort. Our findings require validation in larger cohorts derived from multiple centres.

Strong correlation by ultrasonography of hepatomegaly and the presence of co-infection in HIV/HCV cirrhotic patients

ObjectivesProgression of hepatic fibrosis is accelerated in patients co-infected with human immunodeficiency virus and hepatitis C virus compared to hepatitis C virus mono-infected patients. This study aimed to compare ultrasound features and selected clinical and biochemical variables between patients with human immunodeficiency virus/hepatitis C virus co-infection (n=16) versus hepatitis C virus mono-infection (n=16). MethodsEach patient underwent abdominal ultrasound, and a specific evaluation was performed in order to detect findings consistent with chronic liver disease. Characterization of spleen size, liver structural pattern, diameter of the portal, spleen, and mesenteric veins was based on classical ultrasound parameters. Propensity score was used for control of selection bias and performed using binary logistic regression to generate a score for each patient. The Fisher and Mann–Whitney tests were used to evaluate categorical variables and continuous variables, respectively. ResultsOn univariate analysis right hepatic lobe size was larger in human immunodeficiency virus/hepatitis C virus patients (157.06±17.56mm) compared to hepatitis C virus mono-infected patients (134.94±16.95mm) (p=0.0011). The left hepatic lobe was also significantly larger in human immunodeficiency virus/hepatitis C virus patients (115.88±22.69mm) versus hepatitis C virus mono-infected patients (95.06±24.18mm) (p=0.0177). Also, there was a strong correlation between hepatomegaly and co-infection (p=0.005). ConclusionHuman immunodeficiency virus infection was the primary variable influencing liver enlargement in this population. Hepatomegaly on ultrasound was more common among cirrhotic human immunodeficiency virus/hepatitis C virus co-infected patients than among cirrhotic hepatitis C virus mono-infected patients. This aspect is very important in the management of human immunodeficiency virus/hepatitis C virus co-infected patients, because screening for hepatocellular carcinoma is necessary in this population.

HISTOLOGY AND HISTOMORPHOLOGY OF HORMONE TREATED SURATI BUFFALO UDDER TISSUE

In the global dairy scenario, India has the distinction of being the largest milk producing nation of the total milk production of 100.9 million tons in 2006-2007, about 55.6% has been contributed by buffalo. Buffalo is a more efficient milk producer than an indigenous cow. The present study was carried out to study the morphological changes associated with induced lactation in buffalo mammary gland tissue. Lactation was induced in four non-pregnant, non-lactating buffaloes by subcutaneous injections of estradiol-17β and progesterone for 10 d (@ 0.10 and 0.25 mg kg-1 b. w./d) respectively and Dexamethasone (@ 0.028 mg kg-1 b.w./d) treatment was given on 17th to 19th d. Milking was initiated on day 20. Biopsies of mammary glands were collected on 0, 7th, 14th and 21st day from each animal. Hormonal treatment of mammary tissues of 0 days had abundant connective and adipose tissues with very sparse lobuloalveolar structures. On the 7th day, there was a decrease in stroma, increase in epithelial cell area with increased lobulo-alveolar architecture. There was an accumulation of intracellular and intra-luminal secretions with more lipid droplets. From 7th to 21st day, these changes were progressive although variable amongst buffaloes. The average size of the lobule, alveoli as well as the number and volume of alveoli were significantly increased on the 21st day as compared to 0 day. Increase in size of lobule, alveoli and volume of alveoli and number of alveoli inferred that there was significant physiological changes in the ultrastructure of mammary gland of buffalo. These changes were similar to lactating mammary gland.

The VATLY Radio Telescope

A small radio telescope (SRT) has been installed on the roof of the Hanoi astrophysics laboratory VATLY. It is equipped with a 2.6 m diameter mobile parabolic dish remotely controlled in elevation and azimuth and with super-heterodyne detection around the 21 cm hydrogen line. First results of observations of the Sun and of the centre of the Milky Way are presented. They demonstrate the high quality of the telescope performance and are used to evaluate lobe size, signal to noise ratios, anthropogenic interferences and measurement accuracies. Particular attention is given to the measurement of the pointing accuracy. The rich measurement programme that is now at hand is briefly sketched.

Hereditary lissencephaly and cerebellar hypoplasia in Churra lambs

BackgroundLissencephaly is a rare developmental brain disorder in veterinary and human medicine associated with defects in neuronal migration leading to a characteristic marked reduction or absence of the convolutional pattern of the cerebral hemispheres. In many human cases the disease has a genetic basis. In sheep, brain malformations, mainly cerebellar hypoplasia and forms of hydrocephalus, are frequently due to in utero viral infections. Although breed-related malformations of the brain have been described in sheep, breed-related lissencephaly has not been previously recorded in a peer reviewed publication.ResultsHere we report neuropathological findings in 42 newborn lambs from a pure Churra breed flock, with clinical signs of weakness, inability to walk, difficulty in sucking and muscular rigidity observed immediately after birth. All the lambs showed near-total agyria with only a rudimentary formation of few sulci and gyri, and a severe cerebellar hypoplasia. On coronal section, the cerebral grey matter was markedly thicker than that of age-matched unaffected lambs and the ventricular system was moderately dilated. Histologically, the normal layers of the cerebral cortex were disorganized and, using an immunohistochemical technique against neurofilaments, three layers were identified instead of the six present in normal brains. The hippocampus was also markedly disorganised and the number and size of lobules were reduced in the cerebellum. Heterotopic neurons were present in different areas of the white matter. The remainder of the brain structures appeared normal. The pathological features reported are consistent with the type LCH-b (lissencephaly with cerebellar hypoplasia group b) defined in human medicine. No involvement of pestivirus or bluetongue virus was detected by immunohistochemistry. An analysis of pedigree data was consistent with a monogenic autosomal recessive pattern inheritance.ConclusionsThe study describes the clinical and pathological findings of lissencephaly with cerebellar hypoplasia in Churra lambs for which an autosomal recessive inheritance was the most likely cause. Histopathological features observed in the cerebral cortex and hippocampus are consistent with a possible failure in neuronal migration during brain development. This report suggests that lissencephaly should be considered in the differential diagnosis of congenital neurological disease in newborn lambs showing weakness, inability to walk and difficulty sucking.

A Novel Method of Beamforming to Improve the Space Diversity

At present, the systems of mobile communications demand major capacity in the services, therefore optimum space diversity is needed. In this paper, we propose a ne w method of beam-forming to improve the space diversity and achieve frequency reuse. Our proposal consists in solving a system of linear equations from an 8-elements linear antenna array that increases the size of the side lobes. This method i s compared with the algorithm of Dolph-Chebyshev. Our method shows competitive results in increasing the space diversi ty.

A 3D porous media liver lobule model: the importance of vascular septa and anisotropic permeability for homogeneous perfusion

The hepatic blood circulation is complex, particularly at the microcirculatory level. Previously, 2D liver lobule models using porous media and a 3D model using real sinusoidal geometries have been developed. We extended these models to investigate the role of vascular septa (VS) and anisotropic permeability. The lobule was modelled as a hexagonal prism (with or without VS) and the tissue was treated as a porous medium (isotropic or anisotropic permeability). Models were solved using computational fluid dynamics. VS inclusion resulted in more spatially homogeneous perfusion. Anisotropic permeability resulted in a larger axial velocity component than isotropic permeability. A parameter study revealed that results are most sensitive to the lobule size and radial pressure drop. Our model provides insight into hepatic microhaemodynamics, and suggests that inclusion of VS in the model leads to perfusion patterns that are likely to reflect physiological reality. The model has potential for applications to unphysiological and pathological conditions.

CARACTERIZACIÓN MACROSCÓPICA Y MICROSCÓPICA DE LAS GLÁNDULAS ANEXAS DEL APARATO REPRODUCTOR MASCULINO DE LA LLAMA (Lama glama).

The macroscopic and microscopic structure of the sexual glands of the reproductive tract of the male llama was characterized using eight adult animals. The macroscopic study was done in situ and using extracted organs and samples collected for histological evaluation. The macroscopic examination revealed the presence of two ampoules originating from the vas deferens, the absence of seminal vesicles, and a prostate gland with lobed body, isthmus and a disseminated portion, and two bulbourethral glands. Dilation of the final portion of the vas deferens suggests the presence of ampoules with glandular characteristics. The prostate body has lobular-like shape but without clear delimitations and shows extensions to the urethra in the form of stalks clearly defined in the disseminated portion. The weight and size of the prostatic lobes indicate that there is more glandular mass in the left lobe. The prostatic acini are surrounded by abundant trabeculae connective tissue infiltrated from the capsule tissue. Prostatic ducts have different presentations at their mouths. The two bulbourethral glands are symmetric in size and weight, and are surrounded by abundant skeletal muscle and little connective infiltration tissue. The ducts of the bulbourethral glands drain into a diverticulum that is directed toward the free portion of the penis. It is concluded that the male lama presents certain macroscopic and microscopic particularities in relation to the distribution and mouths of the sexual glands.

Evolution of the Late Ordovician plaesiomyid brachiopod lineage in Laurentia

Multivariate analysis of 197 well-preserved specimens among 11 species of late Late Ordovician (Katian and Hirnantian) plaesiomyid brachiopods from North America revealed two trends of morphological changes: (1) increasing globosity and dorsal convexity from the early to late Katian, and (2) coarser, but fewer ribs in species from the paleoequatorial intracratonic seas compared with species from the mid- to high-tropical pericratonic shelves and platforms. Another notable change, albeit not quantified, was the enlargement of cardinal process in plaesiomyids from early to late Katian, characterized by a predominantly trilobed cardinal process in the intracratonic species versus a bilobed cardinal process in pericratonic species. Increases in dorsal convexity and shell globosity are interpreted to have allowed for development of a larger lophophore, improving the capacity and efficiency of filter feeding and gas exchange. Smaller but more frequently bifurcating ribs would have led to more numerous setae near the margin of the shell, resulting in increased sensitivity to environmental stimuli. Increased size and number of lobes of the cardinal process would have allowed for larger diductor muscles to open a larger, heavier shell. In this study, two new species, Plaesiomys periosa sp. nov. and Plaesiomys lenzi sp. nov., are proposed, and two existing species are transferred from Dinorthis to Plaesiomys.

359 Intrasubject Variation in Estimates of Neonatal Intrahepatocellular Lipid using 1H Nmr Spectroscopy

Background and AimsTo date there are no reports of intra-subject variability for intrahepatocellular lipid (IHCL) assessed using 1H NMR spectroscopy in neonates. This study utilized a high-field (3-Tesla) MRI scanner...

A Morphological Study of the Left Atrial Appendage in Chinese Patients with Atrial Fibrillation

Using angiography, this study examined left atrial appendage (LAA) morphology in Chinese patients with atrial fibrillation (AF) or congenital atrial septal defects (ASD), to provide data that might aid the design of new LAA-occluding devices to prevent cardioembolism and stroke in patients with AF. Patients with AF or ASD were enrolled. The LAA was visualized angiographically; its dimensions were measured and the emptying fraction was calculated. A total of 45 patients with AF and 30 patients with ASD were included in the study. LAA morphology was classified into eight categories. The majority of patients with AF had tube-shaped LAAs with a single lobe; the most common LAA morphologies in patients with ASD were irregular or sphere-like, with multiple lobes. Patients with AF had significantly larger LAAs with significantly lower emptying fractions compared with LAAs of patients with ASD. The LAA demonstrated considerable morpho logical variability in terms of its size, shape and number of lobes. The design of new occluding devices must take into account the size and shape of the LAA in patients with AF.

Distinct copulation positions in Drosophila pachea males with symmetric or asymmetric external genitalia

Left-right asymmetric genitalia have appeared multiple times independently in insects and have been associated with changes in mating positions. However, there is little experimental data on how the evolution of genital asymmetries may have affected the evolution of mating positions or vice versa. As opposed to its closely-related species, Drosophila pachea has a conspicuous asymmetry in its male genitalia external lobes, with the left lobe being 1.49 ± 0.08 (SD) times longer and thinner than the right lobe. In a laboratory stock, we found that 20% of the males possess fully symmetric lobes. To better understand how asymmetric genitalia may affect mating, we compared D. pachea copulation behaviour between these mutant males and wildtype males. We found that D. pachea wild-type males adopt a one-sided mating posture with the male always one-sided 8.55° ± 1.79° (SD) towards the female’s right side. Within 45-min recordings, all wild-type males did mate whereas 39% of symmetric mutants failed to form a stable mating complex and did not mate. In successful copulations, symmetric mutants also adopted a right-sided mating posture but the angle between male and female bodies was significantly more variable compared to wild-type males. Our results suggest that lobe size asymmetry is required for the formation of a stable mating complex and for the positioning of the male according to a precise angle on the female. However, lobe size asymmetry is not required for D. pachea right-sided mating posture.

Analysis on Laminar Chaotic Mixing Based on Configuration of Streak Lobes in an Impeller-Agitated Vessel

In the case of laminar chaotic mixing in a stirred tank, our previous study theoretically revealed that the streakline originating from the tip of the impeller provides the formation of a mixing pattern and its outline comes close to the configuration of the streakline with respect to time. In the present study, the laminar chaotic mixing in a 3-D stirred tank was investigated experimentally by use of a new index, “streak lobes”, which were equivalent to the region surrounded by the streakline. The streak lobes were created by the minute perturbation wave (traveling wave) that is generated by the rotation of the impeller blade in a stirred tank. The amplitude and frequency of their traveling waves were dominant for the size (width and area) and/or number of streak lobes. The experimental results demonstrated that the large area of streak lobes in the 3-D velocity field resulted in good chaotic mixing, even if the number of streak lobes is small. In addition, the fluid exchange between top and bottom regio...

Association of magnetic resonance imaging identification of mesial temporal sclerosis with pathological diagnosis and surgical outcomes in children following epilepsy surgery

Mesial temporal sclerosis (MTS) is widely recognized as a significant underlying cause of temporal lobe epilepsy. Magnetic resonance imaging is routinely used in the preoperative evaluation of children with epilepsy. The purpose of this study was to evaluate the prevalence, reliability, and prognostic value of MRI identification of MTS and MRI findings indicative of MTS in a series of patients who underwent resection of the medial temporal lobe for medically refractory epilepsy. The authors reviewed the medical records and preoperative MRI reports of 25 patients who had undergone medial temporal resections (anterior temporal lobectomy or functional hemispherotomy) for medically intractable epilepsy. The preoperative MRI studies were presented for blinded review by 2 neuroradiologists who independently evaluated the radiographs for selected MTS features and provided a final interpretation. To quantify interrater agreement and accuracy, the findings of the 2 blinded neuroradiologists, the nonblinded clinical preoperative radiology report, and the final pathology interpretation were compared. The preoperative MRI studies revealed MTS in 6 patients (24%), and histopathological analysis verified MTS in 8 (32%) of 25 specimens. Six MRI features of MTS were specifically evaluated: 1) increased hippocampal signal intensity, 2) reduced hippocampal size, 3) atrophy of the ipsilateral hippocampal collateral white matter, 4) enlarged ipsilateral temporal horn, 5) reduced gray-white matter demarcation in the temporal lobe, and 6) decreased temporal lobe size. The most prevalent feature of MTS identified on MRI was a reduced hippocampal size, found in 11 of the MRI studies (44%). Analysis revealed moderate interrater agreement for MRI identification of MTS between the 2 blinded neuroradiologists and the nonblinded preoperative report (Cohen κ 0.40-0.59). Interrater agreement was highly variable for different MTS features indicative of MTS, ranging from poor to near perfect. Agreement was highest for increased hippocampal signal and decreased temporal lobe size and was consistently poor for reduced gray-white matter demarcation. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and proportion perfect agreement were highest for increased hippocampal signal and reduced hippocampal size. An MRI finding of MTS was not predictive of seizure outcome in this small series. Mesial temporal sclerosis identification on brain MRI in children evaluated for medial temporal resections has a PPV of 55%-67% and an NPV of 79%-87%. Increased hippocampal signal and reduced hippocampal size were associated with high predictive values, while gray-white differentiation and an enlarged temporal horn were not predictive of MTS. Seizure outcome following medial temporal resections was not associated with MRI findings of MTS or MRI abnormalities indicative of MTS in this small sample size.

Evolution of brain size in class-based societies of fungus-growing ants (Attini)

A social lifestyle is often assumed to be more complex than a solitary one, due to social demands that may require increased cognitive capabilities. These nested assumptions underlie hypotheses to explain a correlation between brain size and group size in social vertebrates, using group size and accumulation of social traits, as alternative proxies for social complexity. Eusocial insects challenge the generality of the hypothesis that social complexity relies on increased cognitive capabilities of individuals. We used data from previously published studies to test for an association between sociality and brain size across 18 species (nine genera) of fungus-growing ants (Attini), which range from basal taxa with fewer than 100 monomorphic individuals, to derived colonies containing several million polymorphic, highly specialized individuals. Among monomorphic species, increased colony size was associated with decreased relative brain size and increased olfactory lobe size, although the latter result was sensitive to both the exclusion of potential outliers and whether phylogenetically independent contrasts were used. Within leafcutters (Atta), the relative size of the antennal lobes was also associated with group size, but may also reflect ecological foraging specialization, which may be a confounding variable. Comparisons between class- and individual-based societies highlight the general problem of increasing social structure in proportion to group size and show that there are alternative solutions to this problem: one alternative involves increasing behavioural specialization of individuals and evolved rules; the other involves increased diversification of individual behaviour, social norms and ultimately institutions.

Morphometrics and protein profiles of the salivary glands of Phlebotomus papatasi and Phlebotomus langeroni sand flies

Sand fly salivary fluid contains numerous proteins that modulate host immune responses to infection and facilitate blood-feeding and establishing Leishmania infection. Salivary proteins are differentially expressed in adaptation to the host, the meal type and ecological factors. We report on the morphometrics and protein composition of salivary glands of colonised Phlebotomus papatasi and P. langeroni sand flies from Egypt. Female glands were dissected at day 1 (D1, unfed), day 2 (D2, sugar-fed), day 3 (D3, blood-fed) and day 7 (D7, blood-digested). The salivary glands are composed of two lobes: heterogeneous in P. papatasi and homogeneous in P. langeroni. Lobe sizes varied considerably with fly age and feeding state; D3 flies had the largest lobe sizes and protein content. The P. papatasi flies had larger lobes and higher protein content than the P. langeroni flies. The P. papatasi D1 flies had 15 protein bands that decreased in the D2, D3 and D7 flies to 10 bands in the Sinai flies and 9 bands in the Alexandria flies. All P. langeroni flies had 12 protein bands but with different intensities. The results reveal inter-specific variation between P. papatasi and P. langeroni, while no intra-specific variation between P. papatasi strains. These results increase our understanding of salivary gland protein composition and blood-feeding behaviour in Old World sand flies with implications for leishmaniasis epidemiology and control.

Regeneration of olfactory afferent axons in the locust brain

The insect olfactory system consists of thousands of sensory neurons on each antenna, which project into the primary olfactory center, the glomerular antennnal lobe. There, they form synapses with local interneurons and projection neurons, which relay olfactory information to the second-order olfactory center, the mushroom body. Olfactory afferents of adult locusts (Locusta migratoria) were axotomized by crushing the base of the antenna. We studied the resulting degeneration and regeneration in the antennal lobe by size measurements, anterograde dye labeling through the antennal nerve, and immunofluorescence staining of cell surface markers. Within 3 days postcrush, the antennal lobe size was reduced by 30% and from then onward regained size back to normal by 2 weeks postinjury. Concomitantly, anterograde labeling revealed regenerating afferents reaching the antennal lobe by day 4 postcrush, and reinnervating the olfactory neuropil almost back to normal within 2 weeks. Regenerated fibers were directed precisely into the antennal lobe, where they reinnervated glomeruli. As a remarkable exception, a few regenerating fibers projected erroneously into the mushroom body on a pathway that is normally chosen by second-order projection neurons. Regenerating afferents expressed the cell surface proteins lachesin and fasciclin I. The antennal lobe neuropil expressed the cell surface marker semaphorin 1a. In conclusion, axonal regeneration in the locust olfactory system appears to be possible, precise, and fast, opening the possibility of future functional and mechanistic studies.

Hypothyroidism, new nodule formation and increase in nodule size in patients who have undergone hemithyroidectomy

IntroductionThe current medical literature has conflicting results about factors related to hypothyroidism and nodular recurrences during follow-up of hemithyroidectomized patients. We aimed to evaluate factors that may have a role in new nodule formation, hypothyroidism, increase in thyroid lobe and increase in nodule volumes in these patients with and without Hashimoto's thyroiditis (HT), and with and without levothyroxine (LT4) use.Material and methodsWe enrolled 140 patients from five different hospitals in Ankara and evaluated their thyroid tests, autoantibody titre results and ultrasonographic findings longitudinally between two visits with a minimum 6-month interval.ResultsIn patients with HT there was no significant difference between the two visits but in patients without HT, thyroid stimulating hormone (TSH) levels and nodule volume were higher, and free T4 levels were lower in the second visit. Similarly, in patients with LT4 treatment there was no difference in TSH, free T4 levels, or lobe or nodule size between the two visits, but the patients without LT4 had free T4 levels lower in the second visit. Regression analysis revealed a relationship between first visit TSH levels and hypothyroidism during follow-up.ConclusionsPatients who have undergone hemithyroidectomy without LT4 treatment and without HT diagnosis should be followed up more carefully for thyroid tests, new nodule formation and increase in nodule size. The TSH levels at the beginning of the follow-up may be helpful to estimate hypothyroidism in hemithyroidectomized patients.

Multipolar young planetary nebulae modelled as a precessing and orbiting jet with time-dependent ejection velocity

We have carried out 3D hydrodynamic simulations of precessing, variable ejection velocity bipolar jets in order to model multipolar protoplanetary (or planetary) nebulae. For these nebulae, we assume a binary source, with an asymptotic giant branch primary star which ejects an isotropic wind, and a companion which ejects the bipolar jet system. We find that it is possible to relate the large-scale morphological characteristics of these nebulae (lobe size, semi-aperture angle, number of observed lobes) to some of the parameters of the binary system, such as the ratio between the orbital and precession periods, the ratio between the masses of the binary components and the major axis of the elliptical orbit. Our results show that synthetic nebulae with well-defined lobe morphologies (resembling many of the observed multipolar planetary nebulae) are obtained from our models.

Spontaneous regression of hepatocellular carcinoma repeated 3 times with invasion of portal vein and inferior vena cava: report on a rare case.

A 65-year-old man suffered from advanced hepatocellular carcinoma in the right lobe of the liver, for which he received no treatment. His serum was positive for hepatitis C antibody. In spite of his poor prognosis, he remained in good clinical condition and at 6-month follow-up the tumor had regressed without specific treatment, as assessed both radiologically and from a decrease of a previously elevated serum tumor marker level (1st regression). The tumor regrew in size, but at 23-month follow-up could no longer be visualized radiologically (2nd regression). A follow-up computed tomography (CT) scan did not show any relapse of hepatocellular carcinoma until March 2005. At that time, a new lesion had developed in the caudate lobe and tumor size had increased to ≥10cm in diameter, and in June 2006 had invaded the portal vein and inferior vena cava. Afterwards, the tumor lesion gradually decreased again. In June 2007, a CT scan showed a further reduction of tumor size (3rd regression). Here, we report a rare case of spontaneous regression of hepatocellular carcinoma in which spontaneous regression and recurrence were repeated 3 times.