Shimareet Kumar

Primary low-grade B-cell lymphoma of the dura: a mucosa associated lymphoid tissue-type lymphoma.

The clinicopathologic findings in five patients with primary low-grade B-cell lymphoma of the intracranial dura are described. All patients were women, 40-62 years of age, who presented with focal neurologic symptoms. Radiologic studies showed a well-localized dural mass in each case, raising a preoperative diagnosis of meningioma. Cytologically these were composed of a diffuse infiltrate of small lymphocytes with plasmacytoid differentiation, with a variable admixture of centrocytelike cells. Lambda light chain restriction was found in three cases, and kappa light chain in one. VJ polymerase chain reaction for immunoglobulin heavy-chain rearrangement was positive in three of four cases, including one case in which immunostaining results were equivocal. Staging procedures did not show involvement at any other site. Therapy consisted of radiation (n = 3), chemotherapy (n = 1), or both (n = 1), with excellent response. There was no evidence of recurrence or subsequent dissemination at follow-up of up to 63 months. Low-grade B-cell lymphomas arising in the intracranial dura are rare but appear to be similar to other low-grade B-cell lymphomas arising in extranodal sites in terms of clinical presentation as stage 1E disease, indolent behavior, and favorable response to treatment, suggesting that they may be part of the mucosa associated lymphoid tissue (MALT) lymphoma spectrum. They appear to arise at dural sites where meningothelial cells are concentrated.

Focal mesangiolysis and the pathogenesis of the Kimmelstiel-Wilson nodule

Kidneys from 74 consecutively autopsied primarily non-insulin-dependent diabetes cases and 59 age-, sex-, and ethnic group-matched controls were examined qualitatively and semiquantitatively to determine whether focal mesangiolyses (FMs), Kimmelstiel-Wilson (KW) nodules, and glomerular capillary microaneurysms (GCMs) were related lesions, to determine their extent and pathogenic sequence, and to look for associations with structural and functional factors. Light microscopic examination of serial sections, immunohistochemical stains, image analysis, and electron microscopy were used. Focal mesangiolyses, KW nodules, and GCMs occurred in 31 of the 74 diabetes cases (27 had FMs, 29 had KW nodules, and nine had GCMs) and were positively correlated with each other semiquantitatively (r = .71, .70, and .68, respectively). Numerous FMs were found, involving 62% and 78% of the glomeruli in the two most severely affected cases. Most FMs were located at the periphery of KW nodules, but de novo FMs were documented in six cases. Glomerular capillary microaneurysms were deemed occasional complications of FMs because they were much less common, and 25 of the 27 GCMs identified were contiguous with FMs. Focal mesangiolyses and GCMs were deemed transient lesions, being absent in end-stage kidneys. Both FMs and KW nodules consisted of a spectrum of lesions. For the sake of clarity they were arbitrarily divided into two types: edematous and proliferative FMs and simple and complicated KW nodules. Their characteristics suggested the following pathogenic sequence: edematous FM-->proliferative FM-->focal nodular mesangial expansion-->simple KW nodule-->recurrent FM-->complicated KW nodule. Complicated nodules were associated with marked alterations in the lobular capillary. The number of mesangial cells was increased in FMs and they were thought to be responsible for increased matrix production. Focal mesangiolyses and KW nodules were positively associated with diabetes, proteinuria, and hyalinization of afferent and efferent arterioles, but were weakly or not associated with hypertension, arcuate and interlobular artery stenosis, hydroenphrosis, acute pyelonephritis, renal arterial atheromatous emboli, glomerular platelet-fibrin thromboemboli, and congestive heart failure.

Epstein-Barr virus-associated T-cell lymphoma in a renal transplant patient

Posttransplant lymphoproliferative disorders in organ allograft recipients are most commonly of B cell origin, whereas T cell lymphomas are rarely described. We report a case of T cell immunoblastic large cell lymphoma associated with Epstein-Barr virus (EBV) that occurred in a recipient of a cadaveric renal transplant 7 years posttransplantation. On paraffin immunophenotyping, none of the neoplastic cells stained with the T cell-associated markers used, but did show strong CD30 expression. Flow cytometric studies revealed a predominance of T cells without definite evidence of T cell neoplasia. Frozen section immunophenotyping studies revealed a T cell phenotype with aberrant expression, and genotypic studies demonstrated T cell receptor beta gene rearrangement with germline configuration of immunoglobulin heavy chain and kappa light chain genes, confirming a T lineage. EBV-encoded RNA transcripts were demonstrated within the neoplastic cells by in situ hybridization. Southern blot analysis using probes derived from the terminal repeat region of the virus detected a single restriction band indicating a clonal population. We believe this is the first case of a posttransplant T cell lymphoma in which the EBV genome has been demonstrated. This case also illustrates the pitfalls of paraffin immunophenotyping in the diagnosis of T cell lymphoma.

Insudative lesions—Their pathogenesis and association with glomerular obsolescence in diabetes: A dynamic hypothesis based on single views of advancing human diabetic nephropathy

Kidneys from 74 consecutive, primarily non-insulin-dependent diabetics at autopsy and 59 age-, sex, and ethnic group-matched controls were examined qualitatively and semiquantitatively to determine the prevalence and severity of insudative lesions (ILs) and obsolescent glomeruli with (OGcFC) and without (OGsFC) insudative (fibrin cap) lesions. A subset of 25 cases with advanced diabetic changes was examined using serial sections, immunohistochemical stains, and electron microscopy to determine the pathogenesis of ILs and OGcFCs. Insudative lesions consisted of intramural accumulations (hereafter called deposits) of presumably imbibed plasma proteins and lipids within renal arterioles, glomerular capillaries, Bowmans capsule, and proximal convoluted tubules. Insudative lesions in Bowmans capsule are called capsular drop lesions (CDs), in glomerular capillaries they are called fibrin cap lesions (FC), and in afferent and efferent arterioles they are called hyalinized afferent (HA) and hyalinized efferent (HE) arterioles, respectively. All ILs were much more numerous and/or larger in diabetics than in controls. Contrary to previous opinion, CDs and HE arterioles were not specific for diabetes, being present in small numbers in nine (15%) controls. Controls with CD/HE arterioles had far more HA arterioles and focal mesangiolyses (FMs) than those without. Insudative lesions consisted of the well known homogenous eosinophilic deposits (homogenous eosinophilic ILs) and the less familiar foamy, reticulated, and vacuolar deposits (heterogenous lucent ILs). Homogenous eosinophilic ILs were predominant in afferent arterioles and more so in efferent arterioles, and were segregated into globules of varying density with the denser deposits located peripherally. Two types of CDs, which differed sharply in location and composition, were found. The first was mostly homogenous eosinophilic, usually without capsular adhesions and located near the vascular pole close to preglomerular arterioles. The second was mostly heterogenous lucent, located away from the vascular pole, and consistently connected by adhesions to the capillary tuft usually near FMs and/or Kimmelstiel-Wilson (KW) nodules. The latter ILs sometimes extended in continuity along the internal surface of the basement membrane from Bowmans capsule into the proximal convoluted tubule. It was hypothesized that ILs traveled centrifugally through the walls of preglomerular arterioles to form the first type of CD and longitudinally within the walls of afferent arterioles and glomerular capillaries and through adhesions to form the second. Contrary to previous opinion, FCs were consistently intramural. When numerous, FCs were associated with a form of glomerular obsolescence called OGcFC.(ABSTRACT TRUNCATED AT 400 WORDS)

Primary cutaneous Hodgkin's disease with evolution to systemic disease : Association with the Epstein-Barr virus

Hodgkins disease rarely involves the skin and when it does is an indication of advanced stage disease. Primary cutaneous Hodgkins disease is exceedingly rare, and only a few cases are reported. We describe a patient who developed multiple cutaneous lesions of Hodgkins disease 2 years before manifesting nodal disease of mixed cellularity subtype. Reed-Sternberg cells in the skin as well as lymph nodes and bone marrow were positive for Epstein-Barr viral transcripts and expressed viral latent membrane protein. Epstein-Barr virus has not previously been demonstrated in primary cutaneous Hodgkins disease, and its presence in lesions in all sites in this case supports a diagnosis of primary cutaneous disease with subsequent evolution into systemic disease.

Dendrocyte population in cutaneous and extracutaneous Kaposi's sarcoma

In order to investigate the hypothesis that the spindle cells of Kaposis sarcoma originate from dendrocytes, we stained 22 cases of cutaneous and extracutaneous Kaposis sarcoma for the presence of factor XIIIa. We selected eight lesions from the skin, five from the oral mucosa. four from gastrointestinal mucosa, three from lymph nodes, and one each from esophagus and conjunctiva for this study. The majority of cutaneous and lymph node Kaposis sarcoma lesions had a considerable number of dendrocytes admixed with the spindle tumor cells. Of the five oral mucosal lesions only three showed a focal presence of dendrocytes. No dendrocytes were observed in the lesions biopsied from the gastrointestinal mucosa, esophagus, and conjunctiva. Our findings suggest that the proliferation of dendrocytes seen within the lesions of Kaposis sarcoma in the skin and lymph nodes probably represents a nonspecific host response in organs where they are normally present, and it is unlikely that they constitute the neoplastic cells of Kaposis sarcoma.