A case of intravascular large B cell lymphoma with brain involvement mimicking progressive multifocal leukoencephalopathy.

Intravascular large B-cell lymphoma (IVLBCL) is a very rare form of extranodal lymphoma, characterized by the proliferation of neoplastic B cells within the lumen of small vessels. Due to its high aggressivity, for years the prognosis had been really poor with only anectodical cases of remission after traditional chemotherapy. More recently, new therapeutic protocols allowed a significant increase in overall survival. It can virtually involve every organ, being skin and central nervous system the most affected. The clinical presentation is often unspecific and insidious; therefore, diagnosis can be challenging. Tissue biopsy, in particular random deep skin biopsy, is the gold standard for definitive diagnosis. We describe the case of a 58-year-old woman with a previous diagnosis of myelofibrosis, who presented with a rapidly progressive neurological deterioration and a brain MRI suggestive of Progressive Multifocal Leukoencephalopathy. Due to the absence of BK and JC viruses in cerebrospinal fluid and the presence of severe myalgias and subcutaneous nodules, a skin and muscle biopsy was performed, allowing diagnosis of IVLBCL. We describe the diagnostic pitfalls of this case, briefly reviewing existing literature about IVLBCL.

High NESTIN Expression Marks the Endosteal Capillary Network in Human Bone Marrow.

Hematopoiesis is hosted, supported and regulated by a special bone marrow (BM) microenvironment known as "niche." BM niches have been classified based on micro-anatomic distance from the bone surface into "endosteal" and "central" niches. Whilst different blood vessels have been found in both BM niches in mice, our knowledge of the human BM architecture is much more limited. Here, we have used a combination of markers including NESTIN, CD146, and αSMA labeling different blood vessels in benign human BM. Applying immunohistochemical/immunofluorescence techniques on BM trephines and performing image analysis on almost 300 microphotographs, we detected high NESTIN expression in BM endothelial cells (BMECs) of small arteries (A) and endosteal arterioles (EA), and also in very small vessels we named NESTIN+ capillary-like tubes (NCLTs), not surrounded by sub-endothelial perivascular cells that occasionally reported low levels of NESTIN expression. Statistically, NCLTs were detected within 40 µm from bone trabecula, frequently found in direct contact to the bone line and spatially correlated with hematopoietic stem/progenitor cells. Our results support the expression of NESTIN in human BMECs of EA and A in accordance with the updated classification of murine BM micro-vessels. NCLTs for their peculiar characteristics and micro-anatomical localization have been here proposed as transitional vessels possibly involved in regulating human hematopoiesis.

Painless lymphadenopathy, eosinophilia and nephrotic syndrome: a diagnostic challenge in an era of increased migration.

Kimura's disease is a rare chronic inflammatory condition of unknown cause that most frequently affects Asian adults. It is characterized by painless lymphadenopathy in the head and neck region and eosinophilia, often associated with nephrotic syndrome. Α young Asian male presented to our Department with œdema at the lower limbs and scrotum, retroauricular masses, eosinophilia and proteinuria. Diagnosis was reached by a combination of the clinical picture, the patient's origin and a histological examination, which revealed well-developed lymph follicles with increased numbers of eosinophils and fibrosis, a finding typical of Kimura's disease. In case of a young Asian male who is otherwise healthy, but presents head/neck masses and/or unexplained eosinophilia associated with nephrotic syndrome, consider Kimura's disease in the differential diagnosis.

The Combination of Rituximab and Bendamustine as First-Line Treatment Is Highly Effective in the Eradicating Minimal Residual Disease in Follicular Lymphoma: An Italian Retrospective Study.

R-Bendamustine is an effective treatment for follicular lymphoma (FL). Previous large trials demonstrated the prognostic role of the molecular minimal residual disease (MRD) during the most frequently adopted chemotherapeutic regimens, but there are not yet conclusive data about the effect of combination of rituximab (R) and bendamustine in terms of MRD clearance. Thus, the aim of this retrospective study was to assess if and in what extent the combination of rituximab and bendamustine would exert a significant reduction of the molecular disease in 48 previously untreated FL patients. The molecular marker at baseline was found in the 62.5% of cases; no significant differences were observed between patients with or without the molecular marker in respect of the main clinical features. Moreover, the quantization of the baseline molecular tumor burden showed a great variability: the median value was 1.4 × 10-2 copies, ranging from 3 × 10-5 to 4 × 104. The initial molecular tumor burden did not correlate with clinical features and did not impact on the subsequent quality of response. After treatment, 93% of cases became MRD-negative; the median reduction of the BCL2/JH load was 4 logs. The 2-years PFS was 85%; it was significantly longer for patients in complete than for those in partial response (91 vs. 57%; p = 0.002), and for cases with lower FLIPI-2 score (88 vs. 60%; p = 0.004). On the contrary, PFS did not differ between patients with or without the molecular marker at baseline; a molecular tumor burden 15 times higher was observed in the relapsed subgroup in comparison to the relapse-free one, but this difference did not change the PFS length. The 2-years OS was 93.6%; the only variable that significantly impacted on it was the FLIPI-2 score; the presence of the molecular marker at baseline or its behavior after treatment did not impact on survival. This study, even if retrospective and conducted on a small series of patients, would represent a proof of concept that R-bendamustine is able to so efficaciously eradicate MRD that it could be able to by-pass the prognostic significance of MRD already demonstrated for other chemotherapeutic regimens in FL.

Syringocystadenoma Papilliferum of the External Auditory Canal.

BACKGROUND Ceruminous glands are modified apocrine glands, situated in the external auditory canal, that, together with sebaceous glands, produce cerumen, better known as ear wax. The neoplastic transformation of these structures is very rare and there have been few cases reported in the literature. CASE REPORT Syringocystadenoma papilliferum is one of the rarest tumors among benign tumors arising from the ceruminous glands. We here report the case of a 72-year-old man with a lesion histologically documented as a syringocystadenoma papilliferum and we review the literature, focusing our attention on clinical features and treatment options of benign glandular tumors arising from the external auditory canal. CONCLUSIONS Syringocystadenoma papilliferum is a rare benign tumor of the ceruminous glands of the external ear canal. Excision biopsy is mandatory for the diagnosis and is the best treatment.

Osteoid osteoma mimicking monoarticular juvenile idiopathic arthritis in a girl.

Osteoid osteoma (OO) is a benign osteogenic neoplasm, usually affecting children and young adults, that is typically characterized by nocturnal pain and response to non-steroidal anti-inflammatory drugs. OO is frequently misdiagnosed because it mimics juvenile idiopathic arthritis (JIA), bone infection or malignancy. Herein we report the case of a girl who presented with chronic monoarthritis of the knee mimicking JIA. After 1 year, OO of the femoral distal metaphysis was diagnosed. OO was treated with computed tomography-guided radiofrequency ablation with disappearance of the symptoms and resolution of the neoplasm. No recurrences have been observed 3 years after the treatment. This case highlights that intra-articular or juxta-articular OO should be suspected in the case of misleading symptoms and signs, such as swelling, lack of typical pain and synovial thickening on ultrasound; needle biopsy of the lesion is necessary in the case of confusing imaging.

Modifications in B-Lymphocyte Number and Phenotype in the Course of Pregnancy in a Woman with Persistent Polyclonal B-Cell Lymphocytosis: A Flow Cytometric Study.

Persistent polyclonal B-cell lymphocytosis (PPBL) is a rare clinical condition, characterized by a persistent, generally moderate lymphocytosis, generally due to stimulation of central memory B-lymphocytes, and by a moderate increase of polyclonal IgM. In some patients, slight or moderate splenomegaly is observed. A variable percentage of circulating, bone marrow and splenic lymphocytes display an abnormal nucleus (generally bilobated) or are binucleated. The clinical course is benign in most cases and transformation into splenic B-cell lymphoma occurs in few cases. In the current paper we report the first case of pregnancy in PPBL. Our patient became pregnant 18 months after diagnosis. In the course of pregnancy, a marked down-regulation of lymphocytosis (from 6 × 10(9)/L to 2.1 × 10(9)/L) and a decrease in B-lymphocyte number was observed (from 3.6 × 10(9)/L to 1 × 10(9)/L), mainly due to a marked reduction in the percentage and absolute number of central memory B-cells. Such modifications were similar to those described in normal pregnant women. One year after the delivery of a healthy female baby, the number of total lymphocytes and B-lymphocytes showed an inverse behavior, with a new expansion of central memory B-cells. Our case shows that a normal pregnancy can occur in patients with PPBL and that pregnancy can induce marked modifications in B-lymphocyte kinetics and phenotype.

Kinetics of hematogones in bone marrow samples from patients with non-Hodgkin lymphomas treated with rituximab-containing regimens: a flow cytometric study.

Treatment with rituximab, either alone or in combination with antiblastic drugs, causes significant depletion of circulating B-lymphocytes and modifications of B cell maturation in the bone marrow. In the present study, we analyzed the kinetics of hematogones in bone marrow samples from 55 patients suffering from non-Hodgkin lymphomas and treated with rituximab-containing regimens. Maturation arrest at the level of stage 2 hematogones, along with complete depletion of naïve, mature B-lymphocytes, was observed as short-term effects (2 months after completion of chemo-immunotherapy). Further bone marrow samples, obtained 12 months after the last rituximab infusion in 21 patients undergoing long-term follow-up and treated with rituximab maintenance therapy, showed complete normalization of B-lymphocyte ontogeny. Hypogammaglobulinemia developed in 26 patients, and was still observed in nine of the 21 patients undergoing long-term follow-up. Our study provides novel data on hematogone kinetics in the setting of patients with non-Hodgkin lymphomas treated with chemo-immunotherapy containing rituximab and with rituximab maintenance. Our observations show that hypogammaglobulinemia can persist in a significant percentage of patients, despite complete recovery of B-lymphocyte ontogeny.

[Histoplasmosis: the multiple sides of an uncommon disease]. / Istoplasmosi: la multiforme faccia di una patologia rara.

Disseminated histoplasmosis is an invasive fungal infection documented in patients with impaired cellular immunity coming from endemic areas (America, Asia, Africa). We report two cases of disseminated histoplasmosis in AIDS patients paradigmatic of the multifaceted nature of the disease, which may be an expression either of an advanced state of immunosuppression or the immune reconstitution inflammatory syndrome (IRIS).

Myelomatous meningitis evaluated by multiparameter flow cytometry : report of a case and review of the literature.

Central nervous system (CNS) involvement in multiple myeloma (MM) is uncommon. Among its possible presentations, leptomeningeal involvement of MM, also termed central nervous system myelomatosis (CNS-MM) is rare and is characterized by the presence of neoplastic plasma cells in the cerebrospinal fluid (CSF). So far, 187 cases of CNS-MM have been reported : the great majority of them were diagnosed by cytological assays and flow cytometry was used in only eight cases. We describe a case of CNS-MM in a 62-year-old woman, previously treated with chemotherapy (VTD) and autologous peripheral blood hematopoietic stem cell transplantation for stage IIIB IgG-λ MM. After achieving a very good partial response, the patient showed progression of disease, with an extramedullary localization. During administration of second-line therapy, the patient showed severe neurological symptoms. MRI resulted negative. Diagnosis of CNS-MM was made by multiparameter flow cytometry, which showed the presence of CD56(+) plasma cells in a CSF sample, in the absence of plasma cell leukemia. In this paper we also present a review of the eight previous cases of CNS-MM diagnosed by flow cytometry. We found that the application of flow cytometry in cases of MM with neurological symptoms allows a rapid diagnosis of CNS-MM and provides useful information about plasma cell phenotype (including CD56 expression). Some cases of CNS-MM are characterized by normal MRI. In addition, some evidences deriving from the review of literature suggest that CSF monitoring by flow cytometry in such cases might be used to evaluate the efficacy of drugs capable of crossing the blood-brain barrier.

Cerebellar mass as a location of acute lymphoblastic leukaemia.

A 22-year-old man with acute lymphoblastic leukaemia was referred to our observation for headache, cervical pain and sopor. A computed tomography study revealed triventricular obstructive hydrocephalus due to a left cerebellar hyperdense mass impinging on the fourth ventricle. A magnetic resonance study demonstrated an area of hyperintensity on T2-weighted images, hypointensity on T1, restricted diffusivity and contrast enhancement involving the left hemispherical cerebellar cortex and the vermis and causing cerebellar herniation. After surgical excision of the lesion, histological examination revealed an infiltrate of lymphoblastic leukaemia with B cells. Leukaemic intracranial masses are rare. Our report describes a case presenting a cerebellar mass of leukaemic tissue characterized by high cellularity and low apparent diffusion coefficient value comparable to acute ischaemia. Therefore leukaemic intracranial mass has to be considered in the differential diagnosis of cerebellar masses.

Multiparameter Flow Cytometry to Detect Hematogones and to Assess B-lymphocyte clonality in Bone Marrow Samples from Patients with Non-Hodgkin Lymphomas.

Hematogones are precursors of B-lymphocytes detected in small numbers in the bone marrow. Flow cytometry is the most useful tool to identify hematogones and, so far, 4-color methods have been published. In addition, flow cytometry is used in the diagnosis and follow-up of lymphomas. We developed a flow cytometric 7-color method to enumerate hematogones and to assess B-lymphocyte clonality for routine purposes. We evaluated 171 cases of B-cell non-Hodgkin lymphomas, either at diagnosis or in the course of follow-up. By our diagnostic method, which was carried out by the combination K/λ/CD20/CD19/CD10/CD45/CD5, we were able to detect hematogones in 97.6% of samples and to distinguish normal B-lymphocytes, neoplastic lymphocytes and hematogones in a single step. The percentage of hematogones showed a significant inverse correlation with the degree of neoplastic infiltration and, when bone marrow samples not involved by disease were taken into consideration, resulted higher in patients during follow-up than in patients evaluated at diagnosis.

Simultaneous presentation of Waldenström macroglobulinemia and multiple myeloma: multidisciplinary diagnosis, treatment and 30-month follow-up.

Waldenström macroglobulinemia and multiple myeloma are mature B-cell neoplasms deriving from post-germinal cells at different stages of differentiation. The simultaneous presentation of Waldenström macroglobulinemia and multiple myeloma in the same patient is a very rare phenomenon and, so far, only two cases have been described. We report the case of a 75-year Caucasian female patient, with a silent clinical history, who presented with anemia and two different monoclonal proteins (IgMκ and IgGκ). The trephine biopsy showed the presence of a dual population, represented by small lymphoplasmacytoid cells and by plasma cells, which infiltrated the bone marrow with a clearly different pattern. Both immunohistochemistry and flow cytometry demonstrated the biclonal origin such neoplastic cells, since lymphoplasmacytoid cells resulted IgMκ while plasma cells were IgGκ. This biclonal pattern was further confirmed by the demonstration of a different IgH gene rearrangement of the two neoplasms. The patient was treated with bortezomib, dexamethasone and rituximab, achieving partial remission of both Waldenström macroglobulinemia and multiple myeloma. After a 30-month follow-up, she is in stable disease. Multiple myeloma has been described in association with other indolent B-cell neoplasms, mostly chronic lymphocytic leukemia, while Waldenström macroglobulinemia can be followed by diffuse large B-cell lymphoma in some instances, after chemotherapy. The association of Waldenström macroglobulinemia and multiple myeloma seems to be very rare. Our study shows that an integrated diagnostic work-up is very useful in such cases, with an interesting role for flow cytometry. [J Clin Exp Hematop 53(1): 29-36, 2013].

Discordant lymphoma consisting of splenic mantle cell lymphoma and marginal zone lymphoma involving the bone marrow and peripheral blood: a case report.

INTRODUCTION: Discordant lymphomas are rare entities characterized by the simultaneous presence of two distinct types of lymphomas in different anatomic sites. We describe a very rare case of simultaneous occurrence of splenic mantle cell lymphoma and marginal zone lymphoma involving the bone marrow and peripheral blood. CASE PRESENTATION: We report the case of a 60-year-old asymptomatic Caucasian woman in whom discordant lymphomas were discovered when a slight lymphocytosis and a conspicuous splenomegaly were observed. The different morphological, immunophenotypical and immunohistochemical features found in the different pathologic samples obtained from peripheral blood, bone marrow and spleen sections made it possible to differentiate two types of non-Hodgkin B-cell lymphomas: a mantle cell lymphoma infiltrating the spleen and a marginal zone lymphoma involving both the bone marrow and peripheral blood. Since a similar IgH gene rearrangement was found both in the bone marrow and in the spleen, the hypothesis of a common origin, followed by a different clonal selection of the neoplastic lymphocytes may be taken into consideration. CONCLUSION: Our case emphasizes the usefulness of investigating simultaneous specimens from different anatomic sites from the same patient and the relevant diagnostic role of splenectomy.