Determinants of Suboptimal Outcome Following Thymectomy in Myasthenia Gravis.

BACKGROUND: Response to thymectomy in myasthenia gravis (MG) is influenced by various patient-, disease-, and therapy-related factors. METHODS: Retrospective analysis of 128 patients with MG who underwent maximal thymectomy over 15 years was done to identify the determinants of suboptimal clinical outcome. RESULTS: Among the 128 patients, 62 (48.4%) were females with a mean age of 38.97 (12.29) years. Thymomatous MG occurred in 66 (51.6%). Overall improvement from preoperative status was noted in 88 (68.8%) patients after mean follow-up of 51.68 (33.21) months. The presence of thymoma was the major predictor of suboptimal clinical outcome (P = 0.001), whereas age, gender, preoperative disease severity, and seropositive status did not attain significance. Patients with better outcome had received higher steroid dose preoperatively (P = 0.035). CONCLUSIONS: Suboptimal response after thymectomy occurred in one-third of MG patients, more commonly with thymomatous MG. Relationship of preoperative steroid therapy to remission merits evaluation.

Mucormycosis-induced ileocecal perforation: A case report and review of literature.

Gastrointestinal mucormycosis is a rare form of invasive mucormycosis with high fatality rate due to difficulty in establishing its diagnosis. The classic risk-factors include immunosuppression and metabolic derangement. A case of ileocecal mucormycosis following intracardiac repair of congenital heart disease in a 17-year-old boy is described here who lacked the typical risk-factors for mucormycosis. Ileocecal mucormycosis affecting an individual without the classic risk-factors is uncommon.

Plasmacytoma of the clivus.

We report a case of solitary plasmacytoma of the clivus in a 55 year old male.

Quantification of diffusion and anisotropy in intracranial epidermoids using diffusion tensor metrics and p: q tensor decomposition.

PURPOSE: To quantitatively evaluate the diffusion tensor metrics p, q, L and fractional anisotropy in intracranial epidermoids in comparison with normal white matter in the splenium of the corpus callosum. METHODS: This retrospective study included 20 consecutive patients referred to our institute. All patients had a magnetic resonance imaging (MRI) study on a 1.5-Tesla MR system. A spin-echo echo-planar DTI sequence with diffusion gradients along 30 non-collinear directions was performed. The eigen values (λ1, λ2, λ3) were computed for each voxel and, using p: q tensor decomposition, the DTI metrics p, q and L-values and fractional anositropy (FA) were calculated. The region of interest (ROI) (6 pixels each) was placed within the lesion in all the cases and in the splenium of the corpus callosum. RESULTS: The mean FA in the lesion and splenium were 0.50 and 0.88 respectively, with a statistically significant difference between them (P<0.01). On p: q tensor decomposition, the mean p-value in the epidermoid was 1.55±0.24 and 1.35±0.20 in the splenium; the mean q-values in the epidermoid was 0.67±0.13 and 1.27±0.17 in the splenium; the differences were statistically significant (P=0.01 and <0.01 respectively). The significant difference between p- and q-values in epidermoids compared with the splenium of callosum was probably due to structural and orientation differences in the keratin flakes in epidermoids and white matter bundles in the callosum. However, no significant statistical difference in L-values was noted (P=0.44). CONCLUSION: DTI metrics p and q have the potential to quantify the diffusion and anisotropy in various tissues thereby gaining information about their internal architecture. The results also suggest that significant differences of DTI metrics p and q between epidermoid and the splenium of the corpus callosum are due to the difference in structural organization within them.

Rapid and simple method of photobleaching to reduce background autofluorescence in lung tissue sections.

Autofluorescence exhibited by tissues often interferes with immunofluorescence. Using imaging and spectral analysis, we observed remarkable reduction of autofluorescence of formalin fixed paraffin embedded tissues irradiated with light prior to incubation with immunofluorescent dyes. The technique of photobleaching offers significant improvement in the quality and specificity of immunofluorescence. This has the potential for better techniques for disease diagnosis.

Optical diagnosis of the progression and reversal of CCl4-induced liver injury in rodent model using minimally invasive autofluorescence spectroscopy.

Worldwide, liver cancer is the fifth most common cancer in men and seventh most common cancer in women. Intoxicant-induced liver injury is one of the major causes for severe structural damage with fibrosis and functional derangement of the liver leading to cancer in its later stages. This report focuses on the minimally invasive autofluorescence spectroscopic (AFS) studies on intoxicant, carbon tetrachloride (CCl4)-induced liver damage in a rodent model. Different stages of liver damage, including the reversed stage, on stoppage of the intoxicant are examined. Emission from prominent fluorophores, such as collagen, nicotinamide adenine dinucleotide (NADH), and flavin adenine dinucleotide (FAD), and variations in redox ratio have been studied. A direct correlation between the severity of the disease and the levels of collagen and redox ratio was observed. On withdrawal of the intoxicant, a gradual reversal of the disease to normal conditions was observed as indicated by the decrease in collagen levels and redox ratio. Multivariate statistical techniques and principal component analysis followed by linear discriminant analysis (PC-LDA) were used to develop diagnostic algorithms for distinguishing different stages of the liver disease based on spectral features. The PC-LDA modeling on a minimally invasive AFS dataset yielded diagnostic sensitivities of 93%, 87% and 87% and specificities of 90%, 98% and 98% for pairwise classification among normal, fibrosis, cirrhosis and reversal conditions. We conclude that AFS along with PC-LDA algorithm has the potential for rapid and accurate minimally invasive diagnosis and detection of structural changes due to liver injury resulting from various intoxicants.

Intracranial ewings sarcoma/peripheral primitive neuroectodermal tumor.

Central nervous system primitive neuroectodermal tumours (CNS PNET) are aggressive embryonal tumours composed of undifferentiated or poorly differentiated neuroepithelial cells seen in the pediatric age group. This is rare and only a handful of cases of ES/pPNET in CNS are reported. We report such a case in a 3 year old child. Reporting of more such cases is needed to better define these rare tumours of the dura.

Re-colorization of museum specimens: a modification of Romhanyi's technique based on pyridine/nicotine hemochromogen reactions.

Romhanyi's technique for preservation and restoration of color in museum specimens is almost unknown outside Hungary. The technique was based on the use of pyridine, nicotine and sodium dithionite (sodium hydrosulphite) for restoring the natural red color of formalin-fixed gross specimens. We developed a modification of the original technique using a mounting medium containing citrate-phosphate-dextrose (CPD) buffer and glycerin to control pH and osmolality. Specimens re-colorized with the modified and improved Romhanyi technique remained stable with a natural red color, and no histological deterioration, for more than 18 years. The technique demonstrates the formation of red colored complexes between nicotine and pyridine and ferro-hemochromes such as hemoglobin, myoglobin and other cytochromes in tissues, giving specimens a natural color. The modified technique enables further improvement for the old process of re-colorization of museum specimens. In addition, it opens up new methods for demonstration of nicotine, pyridine and their analogues in biological tissues.

Cerebral aneurysms in atrial myxoma: a delayed, rare manifestation.

Atrial myxomas are the most common primary tumors of the heart. Neurologic involvement usually occurs as a stroke with ischemic episodes. Following excision of cardiac myxomas, delayed neurologic events owing to aneurysms are rare and have not been reported from India. We report an operated case of left atrial myxoma. The patient initially presented with a stroke and 6 months after the surgery, developed multiple intracerebral hemorrhages due to the rupture of fusiform cerebral aneurysms, without recurrence of the cardiac tumor.

Clinico-pathological study of cerebral aneurysms.

AIMS AND OBJECTIVES: A clinico-pathological study of cerebral aneurysms was undertaken to understand the histopathogical nature of the lesions and to ascertain possible etiological risk factors. MATERIAL AND METHODS: Of the 255 cases of cerebral aneurysms operated upon at our Institute during the two-year period between Jan 1999 to Dec 2000, a detailed study was conducted on 57 cases where the aneurysm sac could be excised and subjected to histopathological examination. Aneurysm sacs were fixed in 10% buffered formaldehyde and processed through graded alcohol. Paraffin-embedded sections were examined, using hematoxylin and eosin, Verhoeff van Gieson's and toluidine blue staining techniques. Histopathological observations were analyzed and correlated with clinical features. RESULTS: The ages of the patients ranged from 17-65 years and there were 33 males and 24 females. Twenty-six patients were chronic smokers and 19 patients had hypertension. There were 54 saccular and 3 fusiform aneurysms, predominantly involving the anterior circulation (52 cases) than posterior circulation (5 cases). In 35 cases, histopathological studies demonstrated mucoid deposits between hyperplastic cellular elements in the true and false aneurysm wall and/or parent artery or vasavasora. The changes were associated with dystrophic changes in the internal elastic lamina. CONCLUSION: Besides significant risk factors like smoking and hypertension, such mucoid vasculopathic changes may have predisposed vessels to structural weakness and aneurysm formation in our patients.

Teratoma masquerading as catamenial pleural effusion.

Pleural effusion is a common clinical entity in medical practice. We report a case wherein extensive investigations failed to yield a diagnosis and medical management including repeated thoracocentesis left the effusion refractory. The patient, a 26 years lady, gave a definite history of catamenial dry cough and wheeze. The mystery was unraveled following exploratory thoracotomy when a giant mediastinal teratomatous cyst with luteinized ovarian tissue was discovered and removed, leading to eventual cure for the patient.

Atypical meningioma: a clinicopathological analysis.

In this retrospective study, 382 operated cases of meningiomas were reviewed. 32 cases (8.3%) were histopathologically classified as atypical meningioma. The anatomical locations and histological features in all the thirty-two cases were correlated with their recurrence rates and biological behaviour. The overall recurrence rate for atypical meningioma within two years was 28% as compared to 9.3% in benign meningiomas. It is being emphasized that an accurate histopathological interpretation of atypical meningioma is essential for predicting the recurrence, biological behavior as well as post-operative management modalities.

Primary osteogenic sarcoma involving sella-sphenoid sinus--case report.

A 38-year-old male presented with an extremely rare primary osteogenic sarcoma, unassociated with Paget's disease or late effects of radiation, involving the sella and sphenoid sinus region. Complete excision of the tumor was achieved through an extended frontobasal approach. Postoperatively, six cycles of combination chemotherapy (adriamycin, ifosphamide, and cisplatin) followed by a total of 55 Gy local radiotherapy in 33 fractions was given. Primary osteogenic sarcoma should be considered in the differential diagnosis of the central skull base tumors. Osteogenic sarcoma, in general, has a bad prognosis, and should be managed aggressively with multimodality treatment including gross total surgical resection, combination chemotherapy, and radiotherapy.

Bonnet monkey model for pancreatic changes in induced malnutrition.

Pancreatic degenerative lesions of identical nature could be induced in bonnet monkeys (Macaca radiata) fed protein-deficient tapioca or cassava starch-based and corn-starch-based diets for 3 or 5 months. Marked to severe lobular and acinar cell atrophy in animals fed low-protein diets resembled human pancreatic atrophy resulting from protein deficiency. Animals fed low-protein, high-carbohydrate diets showed lesions akin to tropical chronic calculus pancreatopathy with diabetes mellitus. The pancreatic lesions comprised moderate to marked acinar cell atrophy, marked islet hyperplasia or nesidioblastosis with hypertrophy and mucoid metaplasia of the duct epithelium. Mucoid vasculopathy of the pancreatic artery and arterioles was observed in all animals given protein-deficient diets. It was enhanced in those given additional carbohydrate. Identical lesions were observed after using either source of carbohydrate. This excluded the role of toxic factors such as cyanoglycosides or heavy metals from a tapioca source in initiating the lesions. The study establishes monkey models for the spectrum of human pancreatic changes associated with malnutrition owing to protein deficiency and nutritional imbalance with low-protein, high-starch diets. The experiments demonstrate the dual effects of similar diets on the parenchyma and vasculature of the pancreas.

Right atrial lipoma. Case report.

The authors report the successful excision of a right atrial lipoma in an adult male. The rarity of this lesion, clues to diagnosis and its management are discussed.