Lymphoplasmacyte-Rich Meningioma or IgG4-Related Disease: Walking the Thin Line

Lymphoplasmacyte-rich meningioma (LP meningioma) is a rare form of grade 1 meningioma. It shows dense lymphoplasmacytic infiltrate, mimicking an inflammatory lesion. We present a case of Lymphoplasmacyte-rich (LP) meningioma in the left parasagittal region in a 47-year-old female. On histological examination, it showed dense lymphoplasmacytic infiltrate masking the meningothelial component. There was dense fibrosis and numerous IgG4-positive plasma cells (100-120/hpf), admixed with lymphocytes and few histiocytes. The meningothelial component was highlighted by epithelial membrane antigen (EMA) immunostain. The patient had normal serum IgG4 level. This case highlights the morphological overlap between LP meningioma and IgG4-related disease. The presence of fibrosis and increased IgG4-positive plasma cells as a major inflammatory component in LP meningioma, as demonstrated in the present case and some other previous studies raise suspicion of its association with IgG4-related disease. However, this hypothesis requires further detailed studies for confirmation.

IL-17 A correlates with disease progression in papillary thyroid carcinoma

BACKGROUND

Cancer progression can be promoted by chronic inflammation. Local immune response may be associated with favourable or unfavourable prognosis of Papillary Thyroid Carcinoma (PTC). Regulatory T (Treg) cells and T helper 17 (Th17) cells exert opposing function and their balance may have a vital role in promotion of tumor growth. Treg cells in tumor microenvironment (TME) may promote tumor progression and reduced survival of patients. Whereas, Th17 cells can promote or inhibit tumor progression depending on phenotypic characteristics of tumor. In this study, we aimed to analyse the kind of immune response developed and its prognostic impact in future therapeutics.

METHODS

Cytometric Bead Array (CBA) analysis of pro and anti-inflammatory cytokines (IFN-gamma, IL-2, IL-6, IL-17 A, TNF-alpha and IL-4, IL-10) was done in 15 PTC irrespective of Lymphocytic Thyroiditis (LT) and 16 Hashimoto's Thyroiditis (HT) cases. Immunohistochemical expression of FoxP3 and IL-17 A was studied in 27 cases of PTC with LT. Whereas, quantitative gene expression of both was analysed in 10 cases.

RESULTS

All the pro-inflammatory cytokines showed mild elevation in PTC with LT. On IHC, IL-17 A expression was observed in 74% PTC with LT. Whereas, FoxP3 was present in only 40% cases. Also, IL-17 A expression was significantly associated with age group (> 45 years), tumor size ≤ 1 cm and disease progression.

CONCLUSIONS

Increased expression of cytokines suggested correlation between inflammatory factors and progression of thyroid tumors. Along with this, the balance between IL-17 A and FoxP3 may play an important role in PTC development, prognosis and future management.

SDH-B, INSM1, and GATA3 expression in cauda equina neuroendocrine tumors: Report on 21 cases from a north Indian tertiary care centre

BACKGROUND

Primary neuroendocrine tumors (NETs) of the central nervous system (CNS) are rare, primarily seen in the cauda equina region, known as cauda equina NETs. This study was carried out to evaluate the morphological and immunohistochemical characteristics of cauda equina NETs.

MATERIAL AND METHODS

All cases of histologically proven NETs that originated within the spinal cord from 2010 to 2021 were retrieved from the surgical pathology electronic database. For each case, the clinical presentation, site, radiological features, functional status, and pre-operative diagnosis were recorded. Immunohistochemical stains for GFAP, synaptophysin, chromogranin A, cytokeratin 8/18, INSM-1, Ki67, GATA3, and SDH-B were performed for every case using automated immunostainer. GATA3 immunohistochemistry was repeated manually.

RESULTS

A retrospective probe of records revealed 21 cases of NETs having a mean age of 44 years and slight male dominance (M:F ratio 1.2:1). Cauda equina was the most prevalent site of involvement (19, 90.5%). The most typical presentation was lower backache and weakness of bilateral lower limbs. The histopathological features were similar to NETs seen at other sites. Reactivity for at least one neuroendocrine marker was seen in all cases while GFAP was negative. Cytokeratin 8/18 was expressed in the majority (88.9%) of cases. INSM1 and GATA3 expression was seen in 20 (95.2%) and 3 (14.3%) cases, respectively. All cases retained SDH-B cytoplasmic staining. Higher Ki67 index (>3%) was associated with higher risk of recurrence.

CONCLUSIONS

Cauda equina NETs rarely express GATA3 and are unlikely to be associated with SDH mutations. Recurrent cases may be negative for synaptophysin, chromogranin, and cytokeratin; thus INSM1 IHC is helpful.

Role of cytotoxic T cells and PD-1 immune checkpoint pathway in papillary thyroid carcinoma

Background

Lymphocytic thyroiditis (LT) is frequently seen in the tumor microenvironment (TME) of papillary thyroid carcinomas (PTCs). However, the characteristic of these tumor-infiltrating lymphocytes (TILs) is not well understood.

Objective

We aim to define the TME of PTC cases by characterizing the TILs.

Design

This is a cross-sectional observational study.

Patients

We enrolled 29 PTC (23 having concurrent LT), 14 LT, and 13 hyperplastic nodules with LT (HN) patients from January 2016 to December 2020.

Measurements

Immunohistochemical (IHC) expression of CD8, FoxP3, PD-1, and PD-L1 was studied in PTC with LT and compared with HN. PD-1 and PD-L1 expression was correlated at the mRNA level by quantitative real-time PCR. Immunophenotyping of TILs was done in FNAC samples of PTC and LT by flow cytometry.

Results

IHC revealed the presence of CD8+ cytotoxic T lymphocytes (CTLs) and FoxP3+ T regulatory cells (Tregs) in 83% and 52% of PTC with LT cases, respectively. Flow cytometric analysis of the PTC samples revealed a significant abundance of CTL compared with Treg and a higher CTL with lower Treg counts compared with LT. On IHC, PD-1 positivity was noted in 56.5% of PTC with LT cases, while intermediate PD-L1 positivity was found in 70% of the cases. There was a significant upregulation of PD-1 mRNA in PTC with LT. A significant correlation was noted with PD-L1 expression with lymph node metastasis and presence of Treg cells.

Conclusions

Increased expression of PD-1 and PD-L1 in the TME of PTC may provide a potential molecular mechanism for tumor survival despite the predominance of CTLs, possibly through their inactivation or exhaustion.

Acute graft-versus-host-disease in acute myeloid leukemia: Clinicopathological correlation based on autopsy findings

We present a case of acute myeloid leukemia developing acute graft-versus-host-disease (GVHD) in the post transplant phase. The patient had GVHD of skin, liver and gastro-intestinal tract (resolved) with polymicrobial sepsis. The clinical course, treatment and pathological findings on autopsy including the cause of death have been discussed.

Primary diffuse large B-cell lymphoma of the CNS, with a "Lymphomatosis cerebri" pattern

We describe an unusual case of lymphomatosis cerebri in a middle-aged lady presenting with rapid-onset dementia. The lymphomatous infiltrate, instead of forming mass lesions, percolated throughout the brain parenchyma, which is often missed on a stereotactic biopsy and hence warrants caution and awareness about this entity. The nonspecific symptoms at presentation and a variable picture at imaging make this entity diagnostically challenging.

Disseminated TB in inpatient deaths at a tertiary care centre: an autopsy study over three decades

BACKGROUND: One of the most severe forms of TB, disseminated TB (dTB) is associated with significant mortality. A retrospective study was undertaken to assess the proportion of dTB among inpatient deaths and to describe the pathological spectrum of lesions. Associated comorbidities and missed dTB cases ante-mortem were also sought.METHODS: Data on autopsy-confirmed cases of dTB from over three decades (1988-2016) obtained from the departmental archives of the Post Graduate Institute of Medical Education and Research, Chandigarh, India, were reviewed for clinical details, as well as gross and histopathological findings. The proportion of autopsy-confirmed dTB were reported.RESULTS: During this period, a total of 243 autopsy-confirmed cases were retrieved. The organs most commonly involved in these cases were the lungs (90.1%), followed by the liver (72%), spleen (44%), kidneys (37%), bone marrow (17%), adrenals (12.2%), intestine (11.4%), pancreas (8.5%) and reproductive organs (6.9%). The brain was involved in 73.3% cases. In one third of cases, the diagnosis of TB was not suspected ante-mortem. Comorbid conditions were noted in 36.2% cases.CONCLUSION: A significant burden of dTB was noted among hospital inpatient deaths. Due to multi-organ involvement, dTB has atypical symptoms and may remain undiagnosed ante-mortem. Increased awareness and robust screening of TB cases are mandatory, particularly in patients with underlying comorbidities.

Molecular identification of pathogenic fungi in formalin-fixed and paraffin-embedded tissues

Introduction. Histopathological examination (HPE) of tissue helps in the diagnosis of invasive fungal infections (IFIs) but cannot identify the fungus to the genus/species levelGap Statement Available protocols for the molecular identification of fungi from formalin-fixed and paraffin-embedded (FFPE) tissues have limitations in terms of extraction and target selection, and standardisation.Aim. Development of sequence-based fungal identification protocol after extraction of DNA from formalin-fixed and paraffin-embedded (FFPE) tissues.Methodology. A total of 63 FFPE tissues from histopathology proven IFI cases were used to standardize the DNA extraction (commercial QIAamp kit-based extraction and conventional phenol-chloroform-isoamyl alcohol [PCI] method) and sequence-based fungal identification protocols. The PCR targeted different ribosomal DNA (rDNA) regions including complete internal transcribed spacer (ITS1-5.8S-ITS2), separate ITS1 and ITS2, 18S and D1/D2 of 28S regions. Semi-nested PCR targeting Mucorales-specific 18S rDNA region was performed in tissues having aseptate hyphae. The optimized ITS1-PCR protocol was evaluated in 119 FFPE tissues containing septate hyphae or yeast, and Mucorales-specific semi-nested PCR in 126 FFPE tissues containing aseptate hyphae.Results. The DNA yield by conventional PCI method was significantly higher (P<0.0001) than commercial kit, though the quality of DNA was similar by both protocols. The test accuracy was best while using ITS1 (61.9 %) as the target compared to 7.9, 29.9 and 22.2 % on targeting ITS1-5.8S-ITS2, ITS2, the D1/D2 region of 28S, respectively. The test accuracies of ITS1-PCR in tissues containing septate hyphae, aseptate hyphae and yeasts were 75.5, 18.7 and 100 %, respectively. The amplification (targeting ITS1 region) improved by increasing the thickness of tissue section (up to 50 µm) used for DNA extraction. ITS1-PCR protocol could amplify fungal DNA in 76 (63.8 %) tissues and Mucorales-specific semi-nested PCR in 86 (68.3 %) tissues.Conclusion. Conventional PCI-based DNA extraction from thick tissue (50 µm) may be used until optimal commercial fungal DNA extraction kit is developed. Subsequent ITS1-PCR for septate fungi and yeast, and semi-nested PCR targeting 18S rDNA for Mucorales are recommended to identify the fungus in FFPE tissues.

Primary papillary epithelial tumour of the sella: expanding the spectrum of TTF-1-positive sellar lesions

AIM

To describe four novel primary epithelial tumours of the sella with papillary architecture and Thyroid Transcription Factor 1 (TTF-1) expression.

METHODS

Paraffin-embedded tissue from the four cases and recurrence of patient 1 was investigated with haematoxylin-eosin, special histochemical stains, immunohistochemistry with a broad panel of antibodies and next-generation sequencing. The ultrastructure of one tumour was studied in tissue retrieved from paraffin.

RESULTS

The lesions occurred in three females aged 20, 26 and 42 years and a male aged 49 years. They presented with signs and symptoms secondary to pituitary stalk compression. Preoperative neuroimaging documented mixed solid and cystic, enhancing sellar masses with suprasellar extension. Histologically, the tumours showed thin papillae lined by a single layer of cytokeratin and TTF-1-positive cuboidal and cylindrical cells with mildly atypical nucleus. Next-generation sequencing performed in three cases did not identify any mutations. The main differential diagnosis included metastasis from lung or thyroid carcinoma, extraventricular choroid plexus papilloma and sellar ependymoma.

CONCLUSION

We suggest the descriptive term of primary papillary epithelial tumour of the sella (PPETS) for this entity and propose that it could represent the intracranial equivalent of thyroid-like low-grade nasopharyngeal papillary adenocarcinoma. The cell of origin of PPETS remains undetermined although the intense and ubiquitous expression of TTF-1 may suggest a derivation from the infundibulum or ventricular recess. Our study expands the spectrum of sellar TTF-1-positive tumour and challenges the view that they all derive from pituicytes.

Isolated splenic mucormycosis in a case of aplastic anaemia

Mucormycosis, a rare opportunistic infection seen in immunocompromised hosts, is caused by fungi of Mucorales family. It may be confined to the organs, such as rhinocerebral and pulmonary mucormycosis, or may cause disseminated infection. A 14-year-old boy presented to our clinic with fever and left upper quadrant abdominal pain, and on evaluation was found to have pancytopaenia, and imaging revealed ill-defined splenic collection with thrombus in the splenic vein. He was started on empirical intravenous antibiotics, followed by antifungals empirically as he did not show any improvement clinically. Eventually, splenectomy was done, which on histopathological examination revealed mucormycosis. The patient finally succumbed to his illness as he developed peritonitis and refractory shock. To date, only two cases of isolated splenic mucormycosis have been reported. Aggressive treatment is needed, which includes the use of antifungals (amphotericin B) and surgical debridement or resection of the involved tissues or organs.

Primary Intracranial Extraskeletal Mesenchymal Chondrosarcoma: Clinical Mimicry as Glomus Jugulare

BACKGROUND

Extraskeletal mesenchymal chondrosarcoma (ESMCS) is an unusual pathologic variant of chondrosarcoma. There are no specific clinicoradiographic parameters to distinguish it from other intracranial pathologies. The diagnosis can be established only on the basis of histopathology, which may pose significant challenges in certain unusual locations.

PURPOSE

In this case, we discuss the pitfalls in diagnosis, management, and major characteristics of ESMCS with a review of current literature.

METHODS AND RESULTS

A 47-year-old female patient presented with a jugular foramen tumor which was misdiagnosed as glomus jugulare tumor for which she received primary gamma knife radiosurgery at 2 instances. But unfortunately, the patient died because of the increase in size of the lesion associated with necrosis. Autopsy analysis revealed a highly cellular tumor, rich in sarcomatous cells, and well-differentiated cartilages consistent with ESMCS.

CONCLUSION

A definite preoperative diagnosis of ESMCS is crucial though difficult especially when located at complex sites like jugular foramen and clinicoradiological mimicry. The most crucial step in the management of ESMCS is accurate diagnosis with critical evaluation of clinical, radiological, and histopathological parameters and realization of highly variable clinical course of the disease.

Risk of Malignancy and Risk of Neoplasia in the Bethesda Indeterminate Categories: Study on 4,532 Thyroid Fine-Needle Aspirations from a Single Institution in India

OBJECTIVES

To determine the frequency of category 3 (atypia of undetermined significance [AUS]/follicular lesion of undetermined significance [FLUS]), category 4 (follicular neoplasm), and category 5 (suspicious for malignancy) of The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC), the risk of malignancy (ROM) and the risk of neoplasia (RON) in these categories.

STUDY DESIGN

A retrospective 6-year audit of 4,532 thyroid fine-needle aspirations (FNA) reported as per the TBSRTC from a single institution with cytohistological correlation in 335 cases.

RESULTS

The frequency of categories 3, 4, and 5 was 2.5, 3.9, and 0.5%, respectively; the upper and lower bound estimates of ROM being 58.3, 23.6, 75% and 5.1, 5, and 12.5%, respectively. AUS/FLUS (n = 116) cases were subcategorized as AUS, AUS-HC (Hürthle cell), AUS-PTC (AUS-papillary thyroid carcinoma not excluded), FLUS, FLUS-FH (favor hyperplasia), FLUS-HC, and FLUS-PTC. The AUS/FLUS malignancy ratio was 1:3.8. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of FNA thyroid was 80.5, 85.9, 80.7, 85.7, and 82.4%, respectively.

CONCLUSION

Implementation of TBSRTC aided in achieving internal quality control in reporting thyroid FNA cytology. The AUS/FLUS frequency was 2.5%, which is at the lower range of the recommended rate and was associated with a higher than recommended upper bound estimate, but a comparable lower bound estimate of ROM.

Incidental detection of bronchial carcinoid on Tc-99m sestamibi SPECT/CT myocardial perfusion scintigraphy

Technetium-99m sestamibi MPS is a commonly employed imaging study for myocardial perfusion; however, incidental extracardiac sestamibi uptake requires further evaluation, and the tracer uptake in the thorax/mediastinum may be pathological. The authors present a case of significant extra-cardiac uptake seen on stress MPS images helping in the incidental detection of bronchial carcinoid.

Acute respiratory distress syndrome in disseminated tuberculosis: an uncommon association

OBJECTIVE

To analyse clinicopathological features of acute respiratory distress syndrome (ARDS) in disseminated tuberculosis (TB) at autopsy.

METHODS

A retrospective analysis of an autopsy database of disseminated TB from 1990 to 2010 was conducted. ARDS cases were assessed for histological changes of diffuse alveolar damage (DAD) and other pathological pulmonary features.

RESULTS

Disseminated TB was diagnosed in 196 cases. The clinical diagnosis of disseminated TB was made in 67% of cases. Of the 196 cases, 10 met the clinical criteria for ARDS, 60% of whom showed histological evidence of DAD. One case of DAD was diagnosed on histology alone. DAD was thus found in 7/196 cases of disseminated TB. Other pulmonary changes included necrotising granulomas (n = 10), tuberculous bronchopneumonia (n = 4), tuberculous vasculitis (n = 3), infarction (n = 1) and aspergilloma (n = 1). Histopathological diagnosis other than DAD was found in 4/10 cases and disseminated TB was presumed clinically in only 4/10 cases of ARDS.

CONCLUSION

Disseminated TB may be clinically missed and diagnosed only post mortem. Disseminated TB is a relatively uncommon cause of ARDS; however, it should always be presumed clinically as it is a potentially treatable cause. DAD is a rare histological feature of disseminated TB and there may not always be a clinicopathological correlation between ARDS and DAD.

Growth and refinement of excitatory synapses in the human auditory cortex

We had earlier demonstrated a neurofilament-rich plexus of axons in the presumptive human auditory cortex during fetal development which became adult-like during infancy. To elucidate the origin of these axons, we studied the expression of the vesicular glutamate transporters (VGLUT) 1 and 2 in the human auditory cortex at different stages of development. While VGLUT-1 expression predominates in intrinsic and cortico-cortical synapses, VGLUT-2 expression predominates in thalamocortical synapses. Levels of VGLUT-2 mRNA were higher in the auditory cortex before birth compared to postnatal development. In contrast, levels of VGLUT-1 mRNA were low before birth and increased during postnatal development to peak during childhood and then began to decrease in adolescence. Both VGLUT-1 and VGLUT-2 proteins were present in the human auditory cortex as early as 15GW. Further, immunohistochemistry revealed that the supra- and infragranular layers were more immunoreactive for VGLUT-1 compared to that in Layer IV at 34GW and this pattern was maintained until adulthood. As for VGLUT-1 mRNA, VGLUT-1 synapses increased in density between prenatal development and childhood in the human auditory cortex after which they appeared to undergo attrition or pruning. The adult pattern of VGLUT-2 immunoreactivity (a dense band of VGLUT-2-positive terminals in Layer IV) also began to appear in the presumptive Heschl's gyrus at 34GW. The density of VGLUT-2-positive puncta in Layer IV increased between prenatal development and adolescence, followed by a decrease in adulthood, suggesting that thalamic axons which innervate the human auditory cortex undergo pruning comparatively late in development.

Gamma knife for obsessive compulsive disorder: can it be detrimental?

Functional neurological disorders (FND) have been a challenge to treat both for neurologists and neurosurgeons. Various ablative as well as non-ablative techniques have been used to treat these disorders. Gamma knife radiosurgery (GKRS) is also being practised to treat refractory obsessive- compulsive disorder (OCD). The subsequent complications of GKRS reported have been variable, with headache being the most common. We discuss here a rare complication of 'late onset radiation necrosis in bilateral caudate nuclei' in a patient after receiving GKRS three years back. This case highlights the need to be more cautious before administering ablative procedures in patients suffering with functional disorders.

A case of intrauterine diagnosed posterior fossa dermoid presenting in childhood

Intrauterine intracranial brain tumor is a rare entity. Traditionally, the outcome of this tumor had been dismal. In a large series of congenital brain tumor, the commonest have been teratoma followed by astrocytoma and craniopharyngioma. We report a case of intracranial dermoid in post-fossa diagnosed at 8 months of intrauterine life during routine prenatal ultrasonography. The child's clinical picture, the surgery performed and the final outcome have been discussed. As far as our knowledge goes, this is perhaps the first reported case of intrauterine-diagnosed intracranial dermoid.

Enterovirus 71 encephalomyelitis and Japanese encephalitis can be distinguished by topographic distribution of inflammation and specific intraneuronal detection of viral antigen and RNA

AIMS

To investigate if two important epidemic viral encephalitis in children, Enterovirus 71 (EV71) encephalomyelitis and Japanese encephalitis (JE) whose clinical and pathological features may be nonspecific and overlapping, could be distinguished.

METHODS

Tissue sections from the central nervous system of infected cases were examined by light microscopy, immunohistochemistry and in situ hybridization.

RESULTS

All 13 cases of EV71 encephalomyelitis collected from Asia and France invariably showed stereotyped distribution of inflammation in the spinal cord, brainstem, hypothalamus, cerebellar dentate nucleus and, to a lesser extent, cerebral cortex and meninges. Anterior pons, corpus striatum, thalamus, temporal lobe, hippocampus and cerebellar cortex were always uninflamed. In contrast, the eight JE cases studied showed inflammation involving most neuronal areas of the central nervous system, including the areas that were uninflamed in EV71 encephalomyelitis. Lesions in both infections were nonspecific, consisting of perivascular and parenchymal infiltration by inflammatory cells, oedematous/necrolytic areas, microglial nodules and neuronophagia. Viral inclusions were absent.

CONCLUSIONS

Immunohistochemistry and in situ hybridization assays were useful to identify the causative virus, localizing viral antigens and RNA, respectively, almost exclusively to neurones. The stereotyped distribution of inflammatory lesions in EV71 encephalomyelitis appears to be very useful to help distinguish it from JE.

Posterior fossa vermian cystic schwannoma mimicking as pilocytic astrocytoma: a case report and literature review

Intraparenchymal schwannomas are rare and most of the reported cases are in supratentorial region with frontal lobe being most common. Infratentorial location is very rare. We report a posterior fossa midline large cystic schwannoma with mural nodule mimicking as pilocytic astrocytoma. The pathogenesis and neuroradiological findings of intraparenchymal schwannomas are discussed with review of the related literature.

Meningeal inflammation is widespread and linked to cortical pathology in multiple sclerosis

Meningeal inflammation in the form of ectopic lymphoid-like structures has been suggested to play a prominent role in the development of cerebral cortical grey matter pathology in multiple sclerosis. The aim of this study was to analyse the incidence and distribution of B cell follicle-like structures in an extensive collection of cases with secondary progressive multiple sclerosis with a wide age range and to determine their relationship to diffuse meningeal inflammation, white matter perivascular infiltrates and microglial activation. One hundred and twenty three cases with secondary progressive multiple sclerosis were examined for the presence of meningeal and perivascular immune cell infiltrates in tissue blocks and/or whole coronal macrosections encompassing a wide array of brain areas. Large, dense, B cell-rich lymphocytic aggregates were screened for the presence of follicular dendritic cells, proliferating B cells and plasma cells. Ectopic B cell follicle-like structures were found, with variable frequency, in 49 cases (40%) and were distributed throughout the forebrain, where they were most frequently located in the deep sulci of the temporal, cingulate, insula and frontal cortex. Subpial grey matter demyelinated lesions were located both adjacent to, and some distance from such structures. The presence of B cell follicle-like structures was associated with an accompanying quantitative increase in diffuse meningeal inflammation that correlated with the degree of microglial activation and grey matter cortical demyelination. The median age of disease onset, time to disease progression, time to wheelchair dependence and age at death all differed significantly in these cases when compared with those without B cell follicle-like structures. Our findings suggest that meningeal infiltrates may play a contributory role in the underlying subpial grey matter pathology and accelerated clinical course, which is exacerbated in a significant proportion of cases by the presence of B cell follicle-like structures.

The neuropathological basis of clinical progression in multiple sclerosis

Multiple sclerosis is the major inflammatory condition affecting the central nervous system (CNS) and is characterised by disseminated focal immune-mediated demyelination. Demyelination is accompanied by variable axonal damage and loss and reactive gliosis. It is this pathology that is thought to be responsible for the clinical relapses that often respond well to immunomodulatory therapy. However, the later secondary progressive stage of MS remains largely refractory to treatment and it is widely suggested that accumulating axon loss is responsible for clinical progression. Although initially thought to be a white matter (WM) disease, it is increasingly apparent that extensive pathology is also seen in the grey matter (GM) throughout the CNS. GM pathology is characterised by demyelination in the relative absence of an immune cell infiltrate. Neuronal loss is also seen both in the GM lesions and in unaffected areas of the GM. The slow progressive nature of this later stage combined with the presence of extensive grey matter pathology has led to the suggestion that neurodegeneration might play an increasing role with increasing disease duration. However, there is a paucity of studies that have correlated the pathological features with clinical milestones during secondary progressive MS. Here, we review the contributions that the various types of pathology are likely to make to the increasing neurological deficit in MS.

Primary sellar neuroblastoma presenting with syndrome of inappropriate secretion of anti-diuretic hormone

A 29-year-old Ethiopian man presented with marked bilateral visual loss, headache, hypopituitarism and significant hyponatraemia (115 mmol/L). A brain MRI scan demonstrated a large, lobulated, sellar and suprasellar mass, elevating the floor of the 3rd ventricle and compressing the optic chiasm. The patient underwent a transphenoidal resection of the mass followed by a craniotomy 10 days later. Histological examination demonstrated a Hyams' grade III neuroblastoma with ectopic expression of vasopressin. He underwent fractionated radiotherapy at a dose of 60 Gy in 30 fractions. Fourteen months after the onset, he is well with no neuroimaging evidence of tumour recurrence. His serum and urine sodium are completely normalised.

Impaired mitochondrial energy metabolism and neuronal apoptotic cell death after chronic dichlorvos (OP) exposure in rat brain

The present study elucidates a possible mechanism by which chronic organophosphate exposure (dichlorvos 6 mg/kg bw, s.c. for 12 weeks) causes neuronal degeneration. Mitochondria, as a primary site of cellular energy generation and oxygen consumption represent itself a likely target for organophosphate poisoning. Therefore, the objective of the current study was planned with an aim to investigate the effect of chronic dichlorvos exposure on mitochondrial calcium uptake, oxidative stress generation and its implication in the induction of neuronal apoptosis in rodent model. Mitochondrial preparation from dichlorvos (DDVP) treated rat brain demonstrated significant increase in mitochondrial Ca(2+) uptake (644.2 nmol/mg protein). Our results indicated decreased mitochondrial electron transfer activities of cytochrome oxidase (complex IV) along with altered mitochondrial complex I, and complex II activity, which might have resulted from elevated mitochondrial calcium uptake. The alterations in the mitochondrial calcium uptake and mitochondrial electron transfer enzyme activities in turn might have caused an increase in malondialdehyde, protein carbonyl and 8-hydroxydeoxyguanosine formation as a result of enhanced lipid peroxidation, and as well as protein and mtDNA oxidation. All this could have been because of enhanced oxidative stress, decreased GSH levels and also decreased Mn-SOD activity in the mitochondria isolated from dichlorvos treated rat brain. Thus, chronic organophosphate exposure has the potential to disrupt cellular antioxidant defense system which in turn triggers the release of cytochrome c from mitochondria to cytosol as well as caspase-3 activation in dichlorvos treated rat brain as revealed by immunoblotting experiments. Low-level long-term organophosphate exposure finally resulted in oligonucleosomal DNA fragmentation, a hallmark of apoptosis. These studies provide an evidence of impaired mitochondrial bioenergetics and apoptotic neuronal degeneration after chronic low-level exposure to dichlorvos.

Histopatholgical spectrum of thymic neoplasms: twelve-year experience at a referral hospital in north India

This study was undertaken to determine the histopathological spectrum and clinical profile of thymic neoplasms at a tertiary referral care centre. A total of 96 thymectomy specimens were received during the study period (1992-2004), which consisted of 54 neoplasms and 42 benign lesions. Among the neoplasms there were 48 thymic epithelial tumors, 3 thymolipomas and 3 thymic carcinoids. The former comprised of 36 male (75%) and 12 female patients (25%) ranging in age from 2-70 years (mean 37 years). Among paraneoplastic syndromes in thymic epithelial tumours, 27 out of 48 (56.25%) cases were associated with myasthenia gravis and one case was associated with pure red cell aplasia. The most frequent histological subtype was cortical thymoma (43.24%) followed by predominantly cortical (24.32%) and well-differentiated thymic carcinoma (18.92%). On staging, all cases of mixed and predominantly cortical subtype were stage 1 whereas one medullary and 2 cortical thymomas and 4 well differentiated thymic carcinoma (WDTC) showed pleural and pericardial invasion (stage III). This study has revealed that half of thymic epithelial tumours presented as myasthenia gravis. The cortical thymoma was the most frequently encountered histologic subtype and most commonly associated with myasthenia gravis.

Bcl2 and ROS1 expression in human meningiomas: an analysis with respect to histological subtype

Tumors of the central nervous system account for approximately 9% of all primary neoplasm in humans, while tumors of covering elements, the meninges, account for 13-19% and constitute the second largest group of brain tumors. These are known to exhibit a variety of chromosomal abnormalities besides change in the expression level of certain oncogenes. Among oncogenes, bcl2, an anti-apoptotic factor and ROS1 that encodes a protein with a structure similar to the epidermal growth factor (EGF) and insulin receptor and has a tyrosine kinase activity, have been shown to be associated with many malignant tumors. In the present study we have analysed the expression of bcl2 using immuno-histochemistry and ROS1 expression by reverse-transcription coupled with polymerase chain reaction (RT-PCR) of the transcript using primers specific for the intra-cellular domain and then tried to correlate the findings with the subtype of the meningioma defined on the basis of histology. Out of the six bcl2 positive cases in our study, there were three transitional tumors, two fibroblastic and one recurrent meningioma subtype. bcl2 seemed to be more consistently expressed in the cytoplasm of spindle cell component of meningiomas. Thirteen meningiothelial meningiomas did not show any staining for bcl2. ROS1 gene expression could be detected in 4 tumors all of those were Grade-I meningothelial meningiomas. One of the malignant meningioma included in the study was clearly negative for bcl2 as well as ROS1. Thus bcl2 and ROS1 oncogene expression in meningiomas are not concurrent and neither can be ascribed to any histologic subtype or grade of tumor.

A free community approach to classifying disease

Defining and classifying disease is at the heart of medical practice, but the process is slow and laborious. A new "open source" approach could be faster and more democratic

Seborrheic keratosis of the conjunctiva

Seborrheic keratosis can simulate a malignant melanoma and should form the differential diagnosis of a malignant melanoma. Histopathology is confirmatory.

A study of primary central nervous system lymphoma in northern India

BACKGROUND

Primary central nervous system lymphoma (PCNSL) is rare and accounts for 1 to 2% of all lymphomas. There are conflicting reports about the rise in incidence of PCNSL cases in the last two decades; this has largely been attributed to an increase in incidence of AIDS and other immunosuppressive states in some studies. This study was undertaken to view the trend of PCNSL at the Postgraduate Institute of Medical Education and Research, Chandigarh, which is a referral hospital in northern India.

METHODS

The PCNSL cases from our surgical material of 15 years (1985-1999) were reviewed. Slides were examined independently by three histopathologists. Immunophenotyping was done on paraffin-embedded tissue using indirect immunoperoxidase technique.

RESULTS

Out of a total of 3,325 intracranial tumors diagnosed during this period (1985-1999), there were 40 cases (1.2%) of PCNSL; gliomas accounted for 1,531 cases (46.04%). The age ranged from 24-75 years with the sex ratio (M:F) being 2:1. HIV serology, available in 14 cases, was negative in all. The parietal lobe was the most common site of involvement. Diffuse large cell lymphoma was the most common morphological type. Immunohistochemistry could be done in 31 cases; 28 cases were found to be B-cell type whereas 3 cases were T-cell type. No statistically significant increase was seen on comparing the number of cases at 5-year intervals.

CONCLUSION

This study revealed that there has been no significant increase in PCNSL cases over the last 15 years.

Partial nephrectomy in cystic partially differentiated nephroblastoma

Cystic partially differentiated nephroblastoma (CPDN) is an uncommon renal neoplasm in children. It is now recognized as a tumor with low but definite malignant potential. The authors report a patient that was treated with partial nephrectomy and chemotherapy with successful outcome. The literature on CPDN is briefly discussed.

Glioma invasion in vitro is mediated by CD44-hyaluronan interactions

Invasion is a clinically important problem contributing to mortality and morbidity in patients with gliomas, but the mechanism(s) by which glioma cells invade surrounding brain structures is poorly understood. Various experimental models have been used in attempts to elucidate the process of glioma invasion. An in vitro model which is increasingly being employed involves measurement of the rate of invasion of tumour cells through Matrigel-a complex mixture of extracellular matrix components derived from the Engelbroth-Holm-Swarm (EHS) sarcoma. This model has been used to examine the possibility that extracellular hyaluronan (HA) might facilitate the invasive behaviour of human glioma cells. The major component of Matrigel is laminin, with smaller amounts of collagen IV, heparan sulphate proteoglycans, entactin, and nidogen but it lacks HA. In our experiments, we have incorporated HA into Matrigel and have measured its effect on the rate of invasion of human glioma cells in a modified Boyden chamber assay system. The incorporation of HA (50-800 mg/cm2) resulted in a dose-dependent increase in invasion. Invasion was enhanced by up to 70 per cent in comparison with HA-free Matrigel. Since CD44 is a major HA receptor expressed on gliomas, it might have a role in the HA-mediated facilitation of invasion. This was tested by blocking CD44 with specific antibody, which resulted in a 43 per cent reduction in invasion rate. We conclude that in an in vitro model system, HA enhances invasion of glioma cells and that the mechanism involves a CD44-HA interaction.