[Pilomatrixoma of the ocular adnexae: clinical and histologic analysis (13 cases)]

BACKGROUND

Pilomatrixoma (calcifying epithelioma of Malherbe) is a rare benign tumour originating from the matrix of the hair root. In this study, we evaluated the clinical and histopathological characteristics of all the respective tumour specimens submitted to our laboratory since 1997.

PATIENTS/MATERIALS AND METHODS

We reviewed the clinical and histologic findings of 13 pilomatrixomas localised to the ocular adnexae. Paraffin sections were stained with H&E and PAS and, in addition, immunohistochemistry was performed using markers for macrophages (CD68), for proliferative activity (Ki67), and for proliferation/apoptosis (CAS/CSE1L).

RESULTS

All 13 pilomatrixomas were of reddish-livid colour and localised on the upper eyelid and/or near the eyebrow. The patients ages ranged from 4 to 84 years without preference for either gender. In 3 cases the correct diagnosis was made intraoperatively, while no pilomatrixoma was diagnosed prior to surgery. The most frequent false diagnoses were retention cyst (n = 3), atheroma (n = 2), and abscess (n = 2). There was no tumour recurrence in any of the cases within the time period presented. All 13 pilomatrixomas demonstrated the characteristic histology with areas of basophilic islands, shadow cells, calcification and a chronic granulomatous inflammation with foreign body giant cells in varying amounts. Immunhistochemical staining with anti-Ki67 and anti-CAS/CSE1L indicated a regular cellular maturation of the basophilic cells. No correlation was found between any of the histological or immunohistochemical markers and clinical parameters such as size, age and gender of the patient and duration of tumour presence prior to surgery.

CONCLUSIONS

This case series represents one of the largest published so far, and underscores that pilomatrixoma can appear at any age. While it is usually not recognised clinically, it should be considered in the differential diagnosis especially for tumours of the upper eyelid. Our immunohistochemical findings support the basically benign nature of a pilomatrixoma but also point to the chronic inflammatory stimulus that can lead to complications after incomplete removal.

Diagnosis and treatment of acute gastrointestinal haemorrhage in a small district hospital

Ninety-eight consecutive patients admitted to a small district hospital because of acute gastrointestinal haemorrhage have been studied. Patients with haematemesis and/or melaena were treated with antacids and tranexamic acid from the very beginning and were examined with early panendscopy. All patients were closely observed in an ordinary medical ward by a staff especially trained to handle acute gastrointestinal bleeding. Seven patients required acute surgery. The overall mortality was 4.1%. It is concluded that acute gastrointestinal haemorrhage can be successfully handled with modern diagnosis and treatment in a small hospital.

Imaging techniques for Kaposi's sarcoma

Kaposi[']s sarcoma (KS) is a multicentric tumour that most frequently involves the skin but can involve other tissues as well. Clinicians treating patients with KS or conducting clinical trials in this disease can benefit from imaging studies to document the extent of disease, to document changes with therapy, and to assess the extent of visceral and lymphatic involvement. A number of conventional techniques can be of use in meeting these needs, such as conventional light photography to assess skin or mucosal lesions, computed tomography of the chest to assess pulmonary disease, and magnetic resonance imaging. In addition, a number of techniques are being developed with the goals of providing improved differentiation of KS from other diseases or providing information about the degree of angiogenesis in the lesions and other physiological factors. We present here an overview of both established and experimental modalities of imaging in KS.

Detection limits of multi-spectral optical imaging under the skin surface

The present work shows that the optical/biological information contained in a typical spectral image mainly reflects the properties of a small (conic like) volume of tissue situated vertically under each individual pixel. The objects appearing on a spectral image reasonably reproduce the correct geometrical shape and size (like a non-deformed shadow) of underlying inclusions of pathological tissue. The information contained in a spectral image comes from a depth that does not exceed approximately 2-3 mm. The number of photons that visit a given tissue voxel situated at a depth larger than approximately 2 mm represents less than the 1% of the total number of photons reaching the corresponding detection pixel (forming the image). A pathological inclusion (e.g. a pool of blood or vascular tumor) situated at a depth of approximately 0.5 mm with a thickness of 0.5 mm produces an image intensity contrast of approximately 5% (for images taken at wavelengths in the 600-1000 nm range) when compared to the normal skin background. The same inclusion at a depth of 20 microm provides a contrast decreasing from 55 to 20% with respect to an increase in wavelength. The dermis/hypodermis interface behaves as a partial barrier for the photons, limiting their access to deeper skin regions. The image contrast depends on the depth and the type of chromophore contained in the inclusion. An increase in the concentration of a given molecule may produce different contrast, independently of the depth, depending on the characteristics of the skin layer where this change occurs.

Continuous renal replacement therapy in neonates and young infants during extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) is a therapy that ensures adequate tissue oxygen delivery in patients suffering cardiac and/or respiratory failure that are unresponsive to conventional therapy. During ECMO, it is common to see a decrease in urine output that may be associated with acute renal failure. In this context, continuous renal replacement therapy (CRRT) should be considered. Our aim is to evaluate a pioneer experience in Latin America, related to the use of CRRT in a group of neonatal-pediatric patients during ECMO. We conducted a retrospective review of patients treated with ECMO at our institution between May 2003 and May 2005. Twelve infants were treated with ECMO, six of them also underwent CRRT. The main reasons for CRRT initiation were fluid overload and progressive azotemia. Observed complications were clots in the filter and excessive ultrafiltration. CRRT was successful in fluid management and solute clearance in all patients. Discharge survival rate was 83%, all of them with normal renal function. Concurrent CRRT with ECMO is technically feasible and efficacious in the management of fluid overload and solute clearance. We report the first experience with these therapies in a Latin American neonatal-pediatric ECMO program associated with the Extracorporeal Life Support Organization.

Neural Correlations Increase Between Consecutive Processing Levels in the Auditory System of Locusts

Nervous systems may encode information about sensory stimuli using the temporal relations in spiking patterns between neurons. By conducting simultaneous intracellular recordings on pairs of auditory neurons we measured the strength of correlations between elements of the first three processing levels in the metathoracic auditory network of the locust. We quantified the degree of spike synchronization and rate covariations that occur among auditory neurons during acoustic stimulation. In addition to the acoustic stimulation, current pulses were injected into both neurons to study the connectivity within this network. Our findings support the view that the metathoracic auditory system is a hierarchically organized feedforward network. Strong synaptic connections were observed only between consecutive processing levels, whereas there was no indication for strong connections between elements of the same processing level. Both spike synchronization and rate covariations were increased among neurons on higher processing levels. We further investigated the consequences that correlations may have on the common estimates of neuronal variability. For example, rate covariations caused by strong synaptic coupling between two neurons may lead to an overestimation if the variability is measured trial by trial with respect to only single neurons. For the vast majority of cell pairs tested, however, no strong synaptic coupling could be demonstrated. Thus we could show that in most cases no serious errors are made if one determines variability by following the usual procedure on the basis of single-cell recordings.

Corticosteroid-induced osteoporosis in children: outcome after two-year follow-up, risk factors, densitometric predictive cut-off values for vertebral fractures

OBJECTIVE

To identify factors that contribute to a decreased Z score of volumetric spine bone mineral density (ZvSBMD) and the development of vertebral fractures (VF) in children receiving chronic systemic corticosteroid therapy (SCT); to describe their outcome after 2 years, and to define predictive threshold values for ZvSBMD for VF.

METHODS

Fifty-five children on SCT for >or= 6 months were prospectively followed for 2 years. In children with a ZvSBMD > -1.5, we prescribed preventive measures for osteoporosis and densitometry annually. In children with ZvSBMD <or= -1.5, we prescribed spine x-rays and those with VF received alendronate. The association between clinical and biochemical variables and the presence of VF or ZvSBMD were analyzed by logistic regression or multiple regression analysis. The threshold value of ZvSBMD for predicting VF was determined by ROC curve and the probability of having a VF was modeled by multiple logistic regressions.

RESULTS

Children who do not develop osteoporosis at first evaluation tend to maintain normal ZvSBMD after two years. Alendronate increased ZvSBM (median: at baseline: -2.69; 1 yr: -1.92; 2 years: -1.39, p < 0.001). The threshold value of ZvSBMD for predicting VF was -1.8. In this cohort, the risk of developing VF was significantly higher in children who were not ambulatory, growth retarded, treated with methotrexate for a longer time, had a family history of osteoporosis or were of non-aboriginal ancestry.

CONCLUSION

Children on SCT, who do not develop osteoporosis, tend to maintain normal BMD. Children who were not ambulatory, on methotrexate or growth retarded have higher rates of VF.

The Category Cued Recall test in very mild Alzheimer's disease: discriminative validity and correlation with semantic memory functions

Episodic memory tests that measure cued recall may be particularly effective in the diagnosis of early Alzheimer's disease (AD) because they examine both episodic and semantic memory functions. The Category Cued Recall (CCR) test provides superordinate semantic cues at encoding and retrieval, and high discriminative validity has been claimed for this test. The aim of this study was to investigate the discriminative validity for this test when compared with the 10-word memory list from Alzheimer's Disease Assessment Scale (ADAS-cog) that measures free recall. The clinical diagnosis of AD was taken as the standard. It was also investigated whether the two episodic memory tests correlated with measures of semantic memory. The tests were administered to 35 patients with very mild AD (Mini Mental State Examination score >22) and 28 control subjects. Both tests had high sensitivity (>88%) with high specificity (>89%). One out of the five semantic memory tests was significantly correlated to performances on CCR, whereas delayed recall on the ADAS-cog memory test was significantly correlated to two semantic tests. In conclusion, the discriminative validity of the CCR test and the ADAS-cog memory test was equivalent in very mild AD. This may be because CCR did not tap more semantic processes, which are impaired in the earliest phases of AD, than a test of free recall.