Ewing sarcoma arising in colon and ovary––Two rare sites of presentation

Ewing sarcoma is a rare aggressive malignant round cell tumor, primarily presenting in bone and soft tissues. This study presents two cases of this tumor in unusual locations, one in right colon which presented with intussusception and other in ovary which presented clinically as carcinoma ovary. Both the cases showed histomorphology of primitive round cell tumor with characteristic immunohistochemical profile and was confirmed on molecular analysis. We aim to highlight the importance of considering Ewing sarcoma in the differential diagnoses in these locations as they have dismal prognosis with no standard treatment modality.

Recent developments on PET radiotracers for TSPO and their applications in neuroimaging

The 18 kDa translocator protein (TSPO), previously known as the peripheral benzodiazepine receptor, is predominately localized to the outer mitochondrial membrane in steroidogenic cells. Brain TSPO expression is relatively low under physiological conditions, but is upregulated in response to glial cell activation. As the primary index of neuroinflammation, TSPO is implicated in the pathogenesis and progression of numerous neuropsychiatric disorders and neurodegenerative diseases, including Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), Parkinson's disease (PD), multiple sclerosis (MS), major depressive disorder (MDD) and obsessive compulsive disorder (OCD). In this context, numerous TSPO-targeted positron emission tomography (PET) tracers have been developed. Among them, several radioligands have advanced to clinical research studies. In this review, we will overview the recent development of TSPO PET tracers, focusing on the radioligand design, radioisotope labeling, pharmacokinetics, and PET imaging evaluation. Additionally, we will consider current limitations, as well as translational potential for future application of TSPO radiopharmaceuticals. This review aims to not only present the challenges in current TSPO PET imaging, but to also provide a new perspective on TSPO targeted PET tracer discovery efforts. Addressing these challenges will facilitate the translation of TSPO in clinical studies of neuroinflammation associated with central nervous system diseases.

Spectrum of histological features in non-alcoholic fatty liver disease.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) has become an Important entity globally, including in India and other Asian countries. Morphological evaluation of a liver biopsy is necessary for the diagnosis, staging and possibly management of this disease. However, the spectrum of changes in the liver, their evolution, Interrelationships and implications are incompletely understood. We aimed to study the spectrum of histological abnormalities in NAFLD. METHODS: The study material was drawn from a pool of 80 liver biopsies diagnosed in our laboratory as NAFLD, 67 retrieved retrospectively from our records and 13 obtained prospectively with complete clinical data. After comprehensive histological assessment, a detailed analysis was done of 32 of those categorized as definitive NAFLD on the basis of a dependable history of no alcohol Intake and seronegativity for hepatitis virus B and C Infections. RESULTS: Fatty change was preferentially seen in acinar zones 2 and 3, more so in the former. Steatotic cells varied in size; some large ones were non-spherical. Steatosis alone was present in more than a quarter of the cases and steatosis along with inflammation was present in half. The magnitude of steatosis correlated with inflammation, while both these seemed to correlate with hepatocyte Injury and fibrosis. CONCLUSION: A proportion of patients with NAFLD show only hepatic steatosis. An Increasing grade of steatosis is associated with greater Inflammation, hepatocyte injury and acinar fibrosis. Preferential involvement of acinar zone 2 by steatosis, the morphology of the steatotic cells, and nature and location of inflammation are important in the diagnosis of NAFLD and its differentiation from other causes of fatty liver.

Distinguishing between periampullary carcinoids and carcinomas--is this possible preoperatively?

It is difficult to distinguish between carcinoid tumors of the pancreatic head and periampullary region and carcinomas preoperatively. Between 1996 and 2002, 125 consecutive pancreaticoduodenectomies done by us for periampullary tumors (14 carcinoids, 111 carcinomas) were analyzed. Patients with carcinoid tumors had significantly younger mean age (48 vs. 54 years), longer history (32 vs. 8 weeks), lower serum total bilirubin levels (1.4 vs. 6.3 mg/dL) and on CT scan, had larger, well-localized tumors (5 cm vs. 2 cm). Their postoperative course was better with no mortality or major morbidity, whereas after resection for carcinoma 7 (6.3%) patients died and 30 (27%) had major postoperative complications. Thus, a tumor of this region in a young patient with indolent history, low bilirubin level and with CT scan depicting a large expansile lesion suggests a carcinoid. Such tumors may be safely resected with low postoperative morbidity and mortality and good long-term prognosis.

Non-specific interstitial pneumonia in an HIV positive patient.

A 56 year old male presented with features of interstitial lung disease and was detected HIV positive. Histopathology of the lung suggested non-specific interstitial pneumonia with no evidence of tumour or Pneumocystis carinii. The patient responded to steroids and was started on anti-retroviral treatment.

Immunohistochemical detection of serum autoantibodies--a new technique using routine formalin fixed paraffin sections.

Detection of autoantibodies in serum is important in the diagnosis of primary immune mediated diseases. Tests of these antibodies are conventionally done by indirect immunoflourescence (IIF) on frozen sections of fresh target tissues from the murine species. More recently enzyme-linked immunoassays and IIF on cultured human epithelial cells or on fresh frozen sections of murine tissues coated onto wells or glass slides are also being used. But these tests are more expensive and generally not easily available to laboratories in developing countries. Obtaining small animals for preparing frozen sections of fresh tissue is also getting to be increasingly difficult. A simple; new and inexpensive technique was developed to perform IIF on routine paraffin sections of human tissues following antigen unmasking. This, technique offers qualitatively good, consistent, species specific and dependable results with several advantages over the conventional IIF on animal tissue frozen sections, particularly in a sausage block made from different types of tissues. Immunoperoxidase stain for autoantibodies can also be easily performed with the advantages of permanent preservation and clearer evaluation in light microscopy. Most importantly the technique is easily affordable and practicable in all histopathology laboratories.

Scrub typhus: a case report.

Fever with rash is a common cause for dermatological referral. The causes can range from viral to protozoal, bacterial or spirochaetal. A case of rickettsial fever is reported.

CD99 expression in hepatocellular carcinoma: an immunohistochemical study in the fibrolamellar and common variant of the tumour.

Histological diagnosis of hepatocellular carcinoma (HCC) in biopsy and fine needle aspiration material can pose difficult problems. This is particularly so in the fibrolamellar variant of the tumour (FLHCC) which has biological features distinctly different from those of common HCC (CHCC). Expression of CD99, a membrane localised glycoprotein which is known to be a feature of diagnostic importance in several malignant neoplasms was looked for in immunohistochemical preparation of tissue material from 18 cases of HCC, 6 FLHCC and 12 CHCC accessioned in our department. Positive staining of variable degrees and intesity was observed in all 18 cases. Non-neoplastic hepatocytes, normal or others and all the 18 other cases of non-HCC cancers outside the liver or metastatic within the liver were negative. In some cases, mostly of FLHCC, a definitive diagnosis could be suggested on the basis of CD99 positivity. It is concluded that in cases of HCC, particularly in small specimens and in FLHCC, immunostaining for CD99 will be of significant help in diagnosis.

Connective tissue lipoatrophic panniculitis.

A 23 years old girl with a past history of sero-positive oligoarticular juvenile idiopathic arthritis developed nodules and depressed scars over face and limbs. Biopsy from the lesion revealed mixed panniculitis. She responded to steroids and hydroxychloroquine but has residual lipoatrophic scars needing reconstructive surgery.

Choroid plexus papilloma of the fourth ventricle.

A 14 year old girl presented with a 6 months' history of headache with vomiting, ataxia and cerebellar signs. CT and MRI revealed obstructive hydrocephalus secondary to a large fourth ventricular mass which enhanced markedly on contrast administration. Histopathology of the resected mass revealed papillary structures lined by cuboidal cells confirming choroid plexus papilloma.

A multicentric study with arteether in patients of uncomplicated falciparum malaria.

Two hundred and sixty seven patients of uncomplicated P. falciparum malaria completed study in a multicentric phase III clinical trial of Arteether. Arteether was given intramuscularly in a dose of 150 mg daily for three consecutive days. Each patient was followed upto 28 days of alpha, beta arteether therapy. The cure rate was 97% with fever clearance time between 1-7 days (24-168 hours) and parasite clearance time between 1-3 days (24-72 hours). Parasite reappearance rate was found to be 3% and reported at only three of the centres. Following the treatment no adverse effect was observed on haematological, biochemical and vital clinical parameters.