The presence of Mott cells in the lymph nodes of rats with experimental autoimmune encephalomyelitis

Mott cells are plasma cells that have multiple spherical Russell bodies packed in their cytoplasm. Russell bodies are dilated endoplasmic reticulum cisternae filled with aggregates of immunoglobulins that are neither secreted nor degraded. Mott cells were observed in our study by light and electron microscope in the lymph nodes of rats with experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. Mott cells were detected on hematoxylin and eosin (HE)-stained lymph node sections as vacuolated cells with eccentrically positioned nuclei and large number of faint blue spherical inclusions in the cytoplasm. Electron microscopic investigation revealed the presence of Russell bodies of the "medusa" form inside Mott cells in lymph node ultra-thin sections of EAE animals. Mott cells expressed the plasma cell marker CD138 and either kappa or lambda immunoglobulin light chains, indicating their origin from polyclonally activated B cells. Finally, Mott cells were associated with active EAE, as they were not found in the lymph nodes of EAE-resistant Albino Oxford rats. The presence of Russell bodies implies an excessive production of immunoglobulins in EAE, thus further emphasizing the role of B cells, and among them Mott cells, in the pathogenesis of this animal model of multiple sclerosis.

Distribution and Clinicopathological Features of Mott Cells (Plasma Cells Containing Russell Bodies) in Gastric Cancer: Presence of Mott Cells Is Associated with Favorable Prognosis

Gastric cancer (GC) is still one of the leading causes of cancer-related mortality. We previously reported the relationship between histological heterogeneity of tumor cells and molecular features in GC. The tumor microenvironment also has a crucial role in GC progression and therapeutic resistance. In this study, we focused on the tumor microenvironment, especially inflammatory cells in GC. Using GC tissue slides, we investigated the distribution and clinicopathological significance of inflammatory cell counts including eosinophils, neutrophils, lymphocytes, and plasma cells. Additionally, we investigated the relationship between Mott cells (plasma cells containing Russell bodies) and clinicopathological features. In neoplastic gastric mucosa, a high number of plasma cells was associated with low T-grade, early stage, and good prognosis. We then focused on Mott cells and found that their presence in neoplastic gastric mucosa was associated with lower T and N grades, early stage, and Helicobacter pylori infection and was inversely associated with CD44 and EGFR expression. Additionally, the presence of Mott cells was associated with good prognosis in advanced GC and was an independent favorable prognostic predictor. The presence of Mott cells in GC might be one useful prognostic predictor, and Mott cells might have an important role in the carcinogenesis of H. pylori infection.

Surveillance of Russell body inflammation of the digestive tract: a case report and review of literature

Introduction

Russell body inflammation of the digestive tract (RBIDT) is a rare chronic inflammation of the digestive tract mucosa that commonly presents as Russell body gastritis (RBG). This disease is usually associated with Helicobacter pylori (HP) infection. However, it can also occur in individuals without HP infection and with specific immune profiles, as seen in HIV and hepatitis C infections. The aetiology and pathogenesis of this disease remain controversial. Given the rarity of the disease and the diversity of the immunophenotypes, there is a high probability of misdiagnosis.

Case presentation

A male patient with RBG and HP infection was included in this study. The case of RBG with an unusual morphology of Mott cells that mimics stamped ring cells.Endoscopy performed during the follow-up revealed regression of the lesion 1 week after anti-HP treatment.

Conclusions

A case of RBG with a high likelihood of misdiagnosis of signet ring cell carcinoma (SRC) has been reported in this study along with a review of the relevant literature and an overview of RBIDT.

Russell Body Gastroesophagitis Concurrent With Barrett's Esophagus

BACKGROUND

Russell body gastroesophagitis is a rare entity characterized by the accumulation of immunoglobulins within the cytoplasm of plasma cells.

CASE REPORT

Here, we present the case of a 41-year-old male with history of gastroesophageal reflux disease who presented with nausea, vomiting, and altered mental status. Candida esophagitis was noted on upper endoscopy. After treatment, a surveillance endoscopy revealed salmon colored mucosa in the distal esophagus and mild gastric erythema. The biopsy confirmed Barrett's esophagus that was negative for dysplasia and mild chronic inactive gastritis. Interestingly, diffusely infiltrating Russell body-containing plasma cells (Mott cells) were present in the distal esophagus and extending into the gastric cardia. The Mott cells were highlighted on CD138 immunostaining and Periodic acid-Schiff stain. Immunostaining for cytokeratin AE1/AE3 was negative. There was no evidence of Helicobacter pylori organisms on the gastric mucosa.

CONCLUSION

This is the first report on Russell body-containing plasma cells diffusely involving both esophagus and gastric cardia with concurrent Barrett's esophagus.

A case of Russell body gastritis with multifocal lesions

Russell body gastritis is an extremely rare gastritis characterized by abundant infiltration of plasma cells with Russell body and eccentric nuclei, known as Mott cells. An 81-year-old Japanese woman with Helicobacter pylori and hepatitis C virus infection complaining of abdominal discomfort underwent upper gastrointestinal endoscopy, which detected an elevated lesion 2 cm in diameter at the anterior wall of the gastric body. A histological examination of the lesion revealed the infiltration of numerous Mott cells with an abundant eosinophilic crystal structure and eccentric nuclei in the lamina propria, resulting in a pathological diagnosis of Russell body gastritis. Endoscopic submucosal dissection (ESD) was performed subsequently. The histological findings of the resected specimen were compatible with those of Russell body gastritis. Upper gastrointestinal endoscopy performed 2 months after endoscopic submucosal dissection revealed the presence of new multiple flat elevated lesions in the antrum up to 1 cm in diameter, distant from the site of endoscopic submucosal dissection. A histological examination revealed a few Mott cells in the biopsy specimens taken from the new lesions. In turn, H. pylori eradication therapy was performed 1 month after the detection of the new lesions. One year after the eradication therapy, follow-up upper gastrointestinal endoscopy revealed that multiple lesions had almost disappeared, and the histological examination of the gastric biopsy specimens confirmed the disappearance of Mott cells. We herein report a case of Russell body gastritis in which multifocal lesions were observed after endoscopic submucosal dissection, and which was subsequently treated by H. pylori eradication therapy.

Intranuclear inclusions in a dog with B-cell leukemia

A 7-year-old Shetland Sheepdog was presented with anorexia. A CBC indicated thrombocytopenia and neutropenia. Bone marrow cytology revealed that 67.7% of all nucleated cells (ANC) were anaplastic large mononuclear cells. These cells were confirmed to be of B-cell origin based on IgH rearrangement, immunohistochemical, and flow cytometric analysis. Microscopic examination revealed that the neoplastic cells had intranuclear inclusions resembling Dutcher bodies. Immunohistochemistry confirmed that the intranuclear inclusions were immunopositive for IgG antibodies. The periodic acid-Schiff reaction was negative for the presence of polysaccharides and related substances. Although the dog achieved complete remission with a multi-drug chemotherapy protocol, it ultimately died because of tumor progression and acute renal insufficiency on day 201. This is the first known case of canine acute B-cell leukemia with intranuclear inclusions resembling Dutcher bodies.

Primary malignant myelomatous pleural effusion

Primary malignant myelomatous pleural effusion (PMMPE) occurs in less than 1% of patients with multiple myeloma and is diagnosed either by visualization of plasma cells on cytology or by positive flow cytometry. The presence of immature plasma cells characterized by high nucleus to cytoplasm ratio, visible nucleolus and presence of Mott cells and Russell bodies are independent poor prognostic factors. The clinician should differentiate PMMPE from secondary pleural effusion as it is associated with a significantly worse prognosis and poor overall survival.

Enhanced auto-antibody production and Mott cell formation in FcμR-deficient autoimmune mice

The IgM-Fc receptor (FcμR) is involved in IgM homeostasis as evidenced by increased pre-immune serum IgM and natural auto-antibodies of both IgM and IgG isotypes in Fcmr-deficient C57BL/6 (B6) mice. To determine the impact of Fcmr-ablation on autoimmunity, we introduced the Fcmr null mutation onto the Fas-deficient autoimmune-prone B6.MRL Fas (lpr/lpr) mouse background (B6/lpr). Both IgM and IgG auto-antibodies against dsDNA or chromatin appeared earlier in FcμR(-) B6/lpr than FcμR(+) B6/lpr mice, but this difference became less pronounced with age. Splenic B2 cells, which were 2-fold elevated in FcμR(+) B6/lpr mice, were reduced to normal B6 levels in FcμR(-) B6/lpr mice, whereas splenic B1 cells were comparable in both groups of B6/lpr mice. By contrast, marginal zone (MZ) B cells were markedly reduced in FcμR(-) B6/lpr mice compared with either FcμR(+) B6/lpr or wild type (WT) B6 mice. This reduction appeared to result from rapid differentiation of MZ B cells into plasma cells in the absence of FcμR, as IgM antibody to a Smith (Sm) antigen, to which MZ B cells are known to preferentially respond, was greatly increased in both groups (B6/lpr and B6) of FcμR(-) mice compared with FcμR(+) B6/lpr or B6 mice. Mott cells, aberrant plasma cells with intra-cytoplasmic inclusions, were also increased in the absence of FcμR. Despite these abnormalities, the severity of renal pathology and function and survival were all indistinguishable between FcμR(-) and FcμR(+) B6/lpr mice. Collectively, these findings suggest that FcμR plays important roles in the regulation of auto-antibody production, Mott cell formation and the differentiation of MZ B cells into plasma cells in B6.MRL Fas (lpr/lpr) mice.

Russell body duodenitis in a patient with retroperitoneal metastasis of ureteral cancer

Russell bodies are globular and eosinophilic inclusion bodies in the cytoplasm of mature plasma cells. Plasma cells whose cytoplasm is filled with Russell bodies are designated as Mott cells. Russell body duodenitis (RBD) is a unique form of chronic duodenitis that is characterized by infiltration of numerous Mott cells. RBD is very rare; only two cases have been reported to date. In this paper, we report a case of RBD in a patient with retroperitoneal metastasis of ureteral cancer. A 77-year-old man was admitted to our hospital complaining of appetite loss, vomiting, and upper abdominal distension. He had undergone left nephroureterectomy for ureteral cancer 4 years earlier. Upper digestive tract endoscopy revealed edema, stenosis, and punctate redness of the mucosa of the duodenum, and a biopsy was performed. Histological analysis showed that numerous Mott cells had infiltrated the lamina propria mucosae, and the condition was diagnosed as RBD. A mass lesion in the retroperitoneum adjacent to the duodenum was detected by abdominal computed tomography, and was diagnosed as metastatic urothelial carcinoma by biopsy. It is possible that chemokines produced by tumor cells caused RBD in this case.