First reported case of a histiocytic sarcoma in an Armenian hamster (Cricetulus migratorius)

A 14-month-old male Armenian hamster ( Cricetulus migratorius) presented with a spontaneous, subcutaneous, firm mass (4.0 × 2.0 × 1.5 cm) on the ventral neck extending towards the cheek pouch causing multifocal small oral ulcerations. This animal was immunized subcutaneously on the dorsal neck for the development of monoclonal antibodies seven months before presentation. The animal was euthanized and necropsy was performed. Histopathology of the mass showed a well demarcated, multilobulated, unencapsulated, highly cellular, neoplastic mass composed of spindle cells arranged in interlacing streams and bundles, with a moderate amount of fibrovascular stroma. The neoplastic cells exhibited indistinct cell borders and a moderate to large amount of eosinophilic, fibrillar cytoplasm, marked anisocytosis and anisokaryosis, binucleated and multinucleated cells, and high mitotic rate. Based on the histomorphologic features of the mass, and the presence of renal tubular hyaline globules and myeloid hyperplasia in the bone marrow, a diagnosis of histiocytic sarcoma was made. The presumptive diagnosis was confirmed by immunohistochemistry, upon which the neoplastic cells showed strong immunoreactivity for the histiocytic cell markers Iba1 and CD11b. Histiocytic sarcomas have been reported in Syrian ( Mesocricetus auratus) and Siberian dwarf ( Phodopus sungorus) hamsters but, to our knowledge, the current report represents the first case of histiocytic sarcoma described in an Armenian hamster. It is plausible to consider the animal’s experimental immunization history and the development of the histiocytic sarcoma to be related. An association between adjuvanted vaccines and soft-tissue sarcomas has been described in cats and referred to as feline injection-site sarcomas.

Nodular Lymphocyte Predominant Hodgkin Lymphoma - A Retrospective Immunohistochemical Study of Patients in Bangalore, Karnataka

BACKGROUND The term Hodgkin’s lymphoma includes classical Hodgkin lymphoma (CHL) and the less common nodular lymphocyte predominant Hodgkin lymphoma (NLPHL). NLPHL is a B cell neoplasm usually characterised by nodular or follicular and diffuse proliferation of small lymphocytes with single scattered large neoplastic cells (LP/L&H/Popcorn cells). NLPHL accounts for 10 % of all Hodgkin lymphoma. METHODS This is a retrospective study. Histopathology slides and blocks of 24 cases of nodular lymphocyte predominant Hodgkin lymphoma were collected from the archives of histopathology from 2011 to 2015. The immunohistochemistry slides of the corresponding histopathology cases were also assembled. Both the slides were reviewed by three expert onco-pathologists and IHC markers were studied and compared. RESULTS Patients were mostly young between 20 and 40 years (16 / 24, 66.67 %). There was a distinct male preponderance (20 / 24, 83.3 %). Most cases involved cervical, axillary or inguinal lymph nodes, with cervical lymph nodes being the most common (13 / 24, 54 %). It was found that CD45, CD20, CD79a and PAX5 staining highlighted the LP cells in all twenty-four cases, while OCT - 2 and BOB - 1 were highlighted in twenty-three cases (95.8 %), which was statistically significant. CD3 and CD5 IHC staining on T cell rosettes and background reactive T cells were examined, and it was seen that CD3 expression was far more consistent than CD5 expression in T cell rosettes and reactive T cells. Also, it was seen that, those cases which were double positive for CD3 and CD5 constitutes only eight cases (8 / 24, 33.3 %). CONCLUSIONS CD3 is a more consistent marker than CD5 in demonstrating surrounding reactive T cells in NLPHL. CD45, PAX5, CD20, BOB - 1 and OCT - 2 are consistent immunohistochemical markers of LP cells. KEYWORDS Nodular Lymphocyte Predominant Hodgkin Lymphoma (NLPHL), Classical Hodgkin Lymphoma (CHL), Cluster Differentiation (CD), Lymphocyte Predominant Cells (LP Cells), Lymphocyte and Histiocytic Cell (L & H Cell)

Neisseria meningitidis Serogroup B Lipopolysaccharides Induce a Lower Pro-Inflammatory Effect within the Proteoliposome Used in Cuban Anti-Meningococcal Vaccines

Neisseria meningitidis outer membrane vesicles or proteoliposomes (PLs) has been used as vaccines and adjuvant. Despite the presence of potentially toxic amounts of lipopolysaccharide (LPS), they have been shown to be safe, well tolerated, and immunogenic. This suggests that LPS-PL may have reduced LPS toxicity. We show here that the ability of PL to induce pro-inflammatory cytokine production in human U937 histiocytic cell line is significantly lesser than that of an equivalent concentration of purified LPS, thus confirming that certain components or physical properties of PL reduce the pro-inflammatory activity of their endogenous LPS. To investigate the mechanisms responsible for this protective effect, PLs were fractionated and assayed the ability of the resulting fractions to induce inflammatory cytokine expression. Several individual PLs fractions were more potent inducers of pro-inflammatory cytokine production than the unfractionated PLs. The majority of the pro-inflammatory activities appeared to be mediated by the presence of LPS in the fractions, as shown by the ability of an anti-CD14 antibody to block it. However, in two PL fractions, the production of IL-8 and to a lesser extent IL-6 was not inhibited by anti-CD14 treatment, indicating that pro-inflammatory components other than LPS could also be present in PL. Eight proteins present in the fractions were identified by n-terminal sequencing. Our results suggest that two of them PorB and particularly the RmpM protein may also contribute to the pro-inflammatory activity of N. meningitidis PL. Our results could support the development of PLs as vaccine adjuvant.

A Rare Case Report: A Malignant Histiocytic Tumor in the Form of Ovarian Mass

Histiocytic cell malignancies are very rare. Hence, the information about this disease in hematology is limited. In this case report, we present a case of malignant histiocytic tumor affecting the ovary of a 40-year-old virgin female. Primary ovarian malignancy was not considered for the patient who was approached as if she had ovarian malignancy, since there was an indication of a mass in the ovary. Therefore, an aggressive surgery was not performed. Since our patient was in the reproductive age, fertility-preserving surgery was performed. Our patient was then treated systemically by medical oncology. In conclusion, the rare malignancy group was investigated in the present study along with an evaluation of the current literature.

Rosai-Dorfman Disease Originating from Nasal Septal Mucosa

Rosai-Dorfman disease is a rarely seen disease with unknown etiology. Extranodal involvement is most commonly seen in the head and neck region. Histopathologically, it is characterized by histiocytic cell proliferation. This paper presents a case of a 15-year-old male patient who presented with nasal obstruction and was surgically treated for a mass filling in the left nasal meatus that was diagnosed to be Rosai-Dorfman disease by histopathological examination.

Antitumor activity of antimicrobial peptides against U937 histiocytic cell line.

We investigated cytotoxic activity of antimicrobial peptides of different origin (both naturally occurring and synthetic), structure and known mechanisms of action against human histiocytic lymphoma cell line U937. The strongest cytotoxic activity against U937 cell line was shown by Pexiganan MSI-78, followed by Citropin 1.1, Protegrin 1 and a synthetic lipopeptide, N-α-palmitoyl-L-lysyl-L-lysine amide (Pal-Lys-Lys-NH₂). The cytotoxic activity of the peptides was more dependent on the time of incubation than concentration. Only for the lipopeptide, whose mode of action was restricted to disruption of electric potential of the cell membrane, the correlation between cytotoxicity and concentration was almost linear. The high cytotoxicity of Pexiganan MSI-78, Protegrin 1 and the lipopeptide could be basically explained by their membranolytic activity leading to necrosis. However, in the case of Citropin 1.1, the cell membrane integrity was disrupted only slightly and independently of the peptide concentration. Therefore, some other mechanism of action might be responsible for its strong dose-dependent cytotoxic activity, e.g., membranolytic activity leading to apoptosis. Furthermore, TNF-α production due to LPS (lipopolysaccharide) stimulation was suppressed by the presence of Citropin 1.1, Pexiganan MSI-78 or Protegrin 1, but not by Buforin 2 or the lipopeptide. Our experiments have shown that cytotoxic activity is not limited to some specific molecular structure of a peptide, but rather to the length of the peptide chain as it is likely to affect the efficiency of the tumor cell membrane disruption and interaction with LPS.