[Pathogenesis and Targeted Treatment Progress of Splenomegaly in Primary Myelofibrosis--Review].

Primary myelofibrosis (PMF) is a myeloproliferative neoplasm with splenomegaly as the major clinical manifestation, which is commonly considered to be linked to splenic extramedullary hematopoiesis. Alteration of CXCL12/CXCR4 pathway can lead to the migration of hematopoietic stem cells and hematopoietic progenitor cells from bone marrow to spleen which results in splenic extramedullary hematopoiesis. In addition, low GATA1 expression and the abnormal secretion of cytokines were found to be significantly associated with splenomegaly. With the application of JAK1/2 inhibitors in clinical, the symptoms of splenomegaly have been significantly improved in PMF patients. This article will review the pathogenesis and targeted treatment progress of splenomegaly in PMF.

Spleen size greater than 9.76 cm may impact the treatment strategy for blunt splenic injury in adults - A retrospective analysis of experience at a tertiary trauma center in Taiwan.

BACKGROUND/OBJECTIVE: The present study investigated the impact of splenomegaly on the treatment outcomes of blunt splenic injury patients. METHODS: All blunt splenic injury patients were enrolled between 2010 and 2018. The exclusion criteria were age less than 18 years, missing data, and splenectomy performed at another hospital. The patients were divided into two groups based on the presence of splenomegaly, defined as a spleen length over 9.76 cm on axial computed tomography. The primary outcome was the need for hemostatic interventions. RESULTS: A total of 535 patients were included. Patients with splenomegaly had more high-grade splenic injuries (p = 0.007). Hemostatic treatments (p < 0.001) and transarterial embolization (p = 0.003) were more frequently required for patients with splenomegaly. Multivariate analysis showed that male sex (p = 0.023), more packed red blood cell transfusions (p = 0.001), splenomegaly (p = 0.019) and grade 3-5 splenic injury (p < 0.001) were predictors of hemostatic treatment. The failure rate of transarterial embolization was not significantly different between the two groups (p = 0.180). The sensitivity and specificity for splenomegaly in predicting hemostatic procedures were 48.8% and 66.5%, respectively. The positive and negative predictive values were 62.8% and 52.9%, respectively. The overall mortality rate was 3.7%. CONCLUSION: Splenomegaly is an independent predictor for the requirement of hemostatic treatments in blunt splenic injury patients, especially transarterial embolization. Transarterial embolization is as effective for blunt splenic injury patients with splenomegaly as it is for those with a normal spleen.

Efficacy and safety of heparin plus dexamethasone after partial splenic embolization for liver cirrhosis with massive splenomegaly.

PURPOSE: The aim of this study was to investigate the efficacy and safety of the combination of low-molecular-weight heparin + dexamethasone after partial splenic embolization in cirrhotic patients with massive splenomegaly. METHODS: This study included 116 patients with liver cirrhosis complicated with massive splenomegaly who underwent PSE in Union Hospital from January 2016 to December 2019, and they met the criteria. They were divided into two groups: PSE + Hep + Dex group (N = 54) and PSE group (N = 62). We conducted a retrospective study to analyze the efficacy and safety of the two groups of patients. RESULTS: The volume of splenic embolization was 622.34 ± 157.06 cm3 in the PSE + Hep + DEX group and 587.62 ± 175.33 cm3 in the PSE group (P = 0.306). There was no statistically difference in the embolization rate of the spleen between the two groups (P = 0.573). WBC peaked 1 week after PSE and PLT peaked 1 month after PSE in both groups; it gradually decreased later, but was significantly higher than the preoperative level during the 12-month follow-up period. The incidences of abdominal pain (46.3% vs 66.1%, P = 0.039), fever (38.9% vs 75.8%, P < 0.001), PVT (1.9% vs 12.9%, P = 0.026), refractory ascites (5.6% vs 19.4%, P = 0.027) were lower in the PSE + Hep + DEX group than in the PSE group. The VAS score of abdominal pain in PSE group was higher than that in PSE + Hep + DEX group on postoperative days 2-8 (P < 0.05). Splenic abscess occurred in 1(1.6%) patient in the PSE group and none (0.0%) in the PSE + Hep + DEX group (P = 0.349). CONCLUSIONS: The combined use of dexamethasone and low-molecular-weight heparin after PSE is a safe and effective treatment strategy that can significantly reduce the incidence of complications after PSE (such as post-embolization syndrome, PVT, refractory ascites).

Mujer de 66 años con nódulos cutáneos recurrentes, esplenomegalia, anemia hemolítica y neumonía organizada / A 66-year-old woman with recurrent skin nodules, splenomegaly, hemolytic anemia, and organizing pneumonia

We present the case of a women previously diagnosed with nodularpanniculitis (biopsy compatible with neutrophilic dermatosis) andmultifactorial anemia with signs of hemolysis and splenomegaly,who refers reappearance of painful nodules in extremities and general syndrome. The differential diagnosis of the coexistence of these alterations is proposed, with the subsequent solution of the case. (AU)

Presentamos el caso de una mujer con diagnóstico previo de paniculitis nodular con biopsia compatible con dermatosis neutrofílicay anemia multifactorial con componente hemolítico asociada a esplenomegalia, que consulta por reaparición de nódulos dolorososen extremidades y síndrome general. Se plantea el diagnóstico diferencial de la aparición conjunta de estas alteraciones y posteriorresolución del caso clínico. (AU)

Successful haploidentical hematopoietic stem cell transplantation (HSCT) and durable engraftment by repeated donor lymphocyte infusions for a Chinese patient with transfusion-dependent hemoglobin (Hb) Hammersmith and massive splenomegaly.

BACKGROUND: Hemoglobin (Hb) Hammersmith is a rare form of unstable ß-chain hemoglobinopathy causing hemolytic anemia. This rare event led to a more serious transfusion-dependent phenotype in a patient. It was successfully cured by haploidentical hematopoietic stem cell transplantation (HSCT). METHODS AND RESULTS: A 9-year-old mainland Chinese male with a history of neonatal unconjugated hyperbilirubinemia was diagnosed to have hemoglobin (Hb) Hammersmith. He required regular blood transfusion but was unable to be transfused to desired parameters for 8 years prior to transplant due to social and geographical reasons. He subsequently developed marrow hyperplasia and progressive splenomegaly (down to umbilicus level), suggestive of extramedullary hematopoiesis. Eventually, the family came to Hong Kong and complied to a more intensive transfusion regimen and preconditioning chemotherapy 3 months prior to transplant. He underwent haploidentical HSCT using paternal TCRαß/CD45RA-depleted graft but suffered from graft rejection, despite splenic irradiation for massive splenomegaly. It was successfully salvaged with second HSCT with unmanipulated graft from the same donor with additional serotherapy and donor lymphocyte infusions. CONCLUSION: Allogenic haploidentical HSCT for hemoglobin Hammersmith is feasible but adequate immunosuppression during conditioning is crucial. Precise adoptive cell therapy can promote durable engraftment.

Splenomegaly: Diagnosis and Management in Adults.

Splenomegaly can be due to several mechanisms but is almost always a sign of a systemic condition. Patient habits, travel, and medical conditions can increase risk of splenomegaly and suggest etiology. Symptoms can suggest infectious, malignant, hepatic, or hematologic causes. Physical examination will typically reveal splenomegaly, but abdominal ultrasonography is recommended for confirmation. Physical examination should also assess for signs of systemic illness, liver disease, and anemia or other hematologic issues. The most common causes of splenomegaly in the United States are liver disease, malignancy, and infection. Except for apparent causes such as infectious mononucleosis, basic laboratory analysis and ultrasonography are the first-line steps in determining etiology. Malaria and schistosomiasis are common in tropical regions, where as many as 80% of people may have splenomegaly. Management of splenomegaly involves treating the underlying disease process. Splenectomies and spleen reduction therapies are sometimes performed. Any patient with limited splenic function requires increased vaccination and prophylactic antibiotics for procedures involving the respiratory tract. Acute infections, anemia, and splenic rupture are the most common complications of splenomegaly, and people with splenomegaly should refrain from participating in contact sports to decrease risk of rupture.

Impact of TIPS on Splenic Volume and Thrombocytopenia.

OBJECTIVE. Splenomegaly and thrombocytopenia are common complications in patients with cirrhosis. The present study aimed to evaluate changes in splenic volumes and platelet counts after TIPS insertion. MATERIALS AND METHODS. A total of 104 patients who had a diagnosis of portal hypertension and had undergone TIPS placement between November 2015 and August 2019 were enrolled in this retrospective cohort study. We retrospectively calculated splenic volumes before TIPS placement and at 1-2 and 6-12 months after TIPS placement and monitored the platelet count at 1, 3, 6, and 12 months after TIPS placement. RESULTS. The mean (± SD) portal pressure gradient before TIPS placement was 28.3 ± 4.6 mm Hg; after TIPS placement, it was 11.3 ± 4.5 mm Hg (p < .001). The mean splenic volume of all 104 patients before TIPS placement was 868 ± 409 cm3, and at 1-2 months after TIPS placement, it was 710 ± 336 cm3 (p < .001). Among the 43 patients for whom splenic volume data were available at both 1-2 and 6-12 months after TIPS placement, the mean splenic volume decreased from 845 ± 342 cm3 to 691 ± 301 cm3 and then to 674 ± 333 cm3, respectively. Correspondingly, the number of patients with severe thrombocytopenia decreased from 25 patients (35.7%) before the TIPS procedure to 16 patients (22.9%) in the 1-2 months after TIPS placement and then to 11 patients (15.7%) in the 6-12 months after TIPS implantation. The increase in the platelet count was significantly correlated with decreasing splenic volume (r2 = 0.3735; p < .001). CONCLUSION. In most patients, TIPS placement resulted in a significant decrease in splenic volume and a significant increase in the platelet count during the same period.

Non-Pharmacologic Management of Splenomegaly for Patients with Myelofibrosis: Is There Any Role for Splenectomy or Splenic Radiation in 2020?

PURPOSE OF REVIEW: Myelofibrosis is a chronic myeloproliferative neoplasm which can lead to massive splenomegaly. Currently approved medical therapies do not improve splenomegaly in all patients and effects are not sustained. Thus, spleen-directed therapies (i.e., splenectomy and splenic irradiation) have been used in some cases to palliate the signs and symptoms of the disease. Here, we critically review the literature regarding palliative splenectomy and splenic irradiation in myelofibrosis, and discuss their position in the current treatment landscape. RECENT FINDINGS: Retrospective studies have demonstrated that splenectomy improves symptoms of splenomegaly, decreases complications of portal hypertension, and decreases transfusion dependence. However, it carries a significant peri-operative and long-term morbidity and mortality rate. Splenic irradiation reduces splenic size but is limited by duration of response and myelosuppression. Spleen-directed therapies in myelofibrosis may be considered for refractory symptoms and complications of massive splenomegaly after carefully weighing the associated risks, though overall survival may not be impacted. Development of medical therapies that target and reverse the underlying disease pathophysiology is required in order to have a significant impact on the natural history of the disease process.

Clinical relevance of endpoints in clinical trials for acid sphingomyelinase deficiency enzyme replacement therapy.

BACKGROUND: Acid sphingomyelinase deficiency (ASMD) also known as Niemann-Pick disease, is a rare lysosomal storage disorder with a diverse disease spectrum that includes slowly progressive, chronic visceral (type B) and neurovisceral forms (intermediate type A/B), in addition to infantile, rapidly progressive fatal neurovisceral disease (type A). PURPOSE AND METHODS: We review the published evidence on the relevance of splenomegaly and reduced lung diffusion capacity to the clinical burden of chronic forms of ASMD. Targeted literature searches were conducted to identify relevant ASMD and non-ASMD studies for associations between diffusing capacity of the lungs for carbon monoxide (DLCO) and splenomegaly, with clinical parameters and outcome measures. RESULTS: Respiratory disease and organomegaly are primary and independent contributors to mortality, disease burden, and morbidity for patients with chronic ASMD. The degree of splenomegaly correlates with short stature, atherogenic lipid profile, and degree of abnormality of hematologic parameters, and thus may be considered a surrogate marker for bleeding risk, abnormal lipid profiles and possibly, liver fibrosis. Progressive lung disease is a prevalent clinical feature of chronic ASMD, contributing to a decreased quality of life (QoL) and an increased disease burden. In addition, respiratory-related complications are a major cause of mortality in ASMD. CONCLUSIONS: The reviewed evidence from ASMD natural history and observational studies supports the use of lung function and spleen volume as clinically meaningful endpoints in ASMD trials that translate into important measures of disease burden for patients.

Left-sided portal hypertension after pancreatoduodenectomy with resection of the portal/superior mesenteric vein confluence. Results of a systematic review.

BACKGROUND: Pancreatoduodenectomy with synchronous resection of the portal vein/superior mesenteric vein confluence may result in the development of left-sided portal hypertension. Left-sided portal hypertension presents with splenomegaly and varices and may cause severe gastrointestinal bleeding. The aim of the study is to review the incidence, treatment, and preventive strategies of left-sided portal hypertension. METHODS: A systematic literature search was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement to identify all studies published up to September 30, 2019 reporting data on patients with left-sided portal hypertension after pancreatoduodenectomy with venous resection. RESULTS: Eight articles including 829 patients were retrieved. Left-sided portal hypertension occurred in 7.7% of patients who had splenic vein preservation and 29.4% of those having splenic vein ligation. Fourteen cases of gastrointestinal bleeding owing to left-sided portal hypertension were reported at a mean interval of 28 months from pancreatoduodenectomy. Related mortality at 1 month was 7.1%. Treatment of left-sided portal hypertension consisted of splenectomy in 3 cases (21%) and colectomy in 1 (7%) case, whereas radiologic, endoscopic procedures or conservative treatments were effective in the other cases (71%). CONCLUSION: Left-sided portal hypertension represents a potentially severe complication of pancreatoduodenectomy with venous resection occurring at greater incidence when the splenic vein is ligated and not reimplanted. Left-sided portal hypertension-related gastrointestinal bleeding although rare can be managed depending on the situation by endoscopic, radiologic procedures or operative intervention with low related mortality.

Modern management of splenomegaly in patients with myelofibrosis.

Myelofibrosis (MF) is a chronic myeloproliferative neoplasm which can lead to massive splenomegaly secondary to extramedullary hematopoiesis. Patients frequently exhibit debilitating symptoms including pain and early satiety, in addition to cellular sequestration causing severe cytopenias. JAK 1/2 inhibitors, such as ruxolitinib and fedratinib, are the mainstay of therapy and produce significant and durable reductions in spleen volume. However, many patients are not eligible for JAK 2 inhibitor therapy or become refractory to treatment over time. Novel therapies are in development that can reduce the degree of splenomegaly for some of these patients. However, splenectomy, splenic irradiation, and partial splenic artery embolization remain valuable therapeutic options in select patients. In this review, we will discuss currently available pharmacologic therapies and describe promising drugs currently in development. We will also delve into the efficacy and safety concerns of splenectomy, splenic irradiation, and partial splenic artery embolization. Finally, we will propose a treatment algorithm to help guide clinicians in the management of symptomatic splenomegaly in patients with MF.

Partial Splenic Artery Embolization in 35 Cancer Patients: Results of a Single Institution Retrospective Study.

PURPOSE: To evaluate the safety and efficacy of partial splenic embolization (PSE) in cancer patients with different etiologies of splenomegaly/hypersplenism. MATERIALS AND METHODS: The medical records of 35 cancer patients who underwent 39 PSE procedures were analyzed. The splenomegaly/hypersplenism was due to chemotherapy (n = 17), portal hypertension (n = 10), or hematologic malignancy (n = 8). After the first 11 PSEs, celiac plexus neurolysis, corticosteroids, and non-steroid anti-inflammatory drugs (NSAIDs) were included in the post-procedural management. RESULTS: PSE led to 59 ± 16% (mean ± standard deviation) splenic infarcts. The infarct volume per 1 mL 300-500 µm tris-acryl gelatin microspheres was not significantly different between the chemotherapy-induced group (264 ± 89 cm3) and the portal hypertension group (285 ± 139 cm3) but was significantly higher in the hematology group (582 ± 345 cm3). Platelet count increased from 65.7 ± 19.7 k/µl to a peak platelet count of 221 ± 83 k/µl at 2 weeks after PSE. Patients with a follow-up period of more than 1 year had the most recent platelet count of 174 ± 113 k/µl. Platelet count increase was significantly higher in the chemotherapy-induced group than the portal hypertension group. Adding celiac plexus neurolysis, corticosteroids, and NSAIDs to the post-procedural management resulted in a decreased rate of major complications from 73% to 46% and a decrease in the rate of moderate or severe pain from 92% to 20%. CONCLUSIONS: PSE improved platelet counts in cancer patients despite different etiologies of splenomegaly. The addition of celiac plexus neurolysis, corticosteroids, and NSAIDS to the post-PSE treatment protocol reduced complications. Data from this study could help to predict the amount of 300-500 µm tris-acryl gelatin microspheres required to achieve a planned infarct size.

Morphological changes in spleen after dietary zinc deficiency and supplementation in Wistar rats.

BACKGROUND: Study was conducted to determine the effect of dietary zinc deficiency and supplementation on the spleen morphology. METHODS: Pre-pubertal Wistar rats (40-50 g) were divided into two groups with 6 sub-groups each viz. zinc control (ZC, 100 µg/g zinc diet), pair fed (PF, 100 µg/g zinc diet), zinc deficient (ZD, <1 µg/g zinc diet, zinc supplementation control (ZCS), zinc supplementation pair-fed (PFS) and zinc supplementation deficient (ZDS, 100 µg/g zinc control diet). Experiments were set for 2- and 4-weeks followed by 4 weeks of zinc supplementation. RESULTS: In the present study body weight and BMI decreased significantly along with incidence of splenomegaly as typified by the increased splenic index in deficient groups compared with that of respective control groups. Histopathological changes such as disorganization of red pulp, several infiltered lymphocytes, vacuolization, loss of cellularity, karyolysis, dissolution of matrix, indistinct differentiation between red and white pulp were evident in spleen of 2ZD and 4ZD group animals. Degeneration was more severe after 4 weeks of zinc deficiency as giant cells formation and hypertrophy were also evident. CONCLUSION: The findings revealed that zinc deficiency causes growth retardation and splenomegaly. Degenerative and atrophic changes in rat spleen suggest reduced cellular defense potential which will have a direct effect on immunity. Zinc supplementation may prove to be beneficial as there were varying degrees of cellular recovery after cessation of zinc deficiency.

Clinical features of idiopathic portal hypertension in China: A retrospective study of 338 patients and literature review.

BACKGROUND AND AIM: Idiopathic portal hypertension (IPH) refers to a relatively rare condition characterized by intrahepatic portal hypertension in the absence of underlying disease such as liver cirrhosis. METHODS: We retrospectively reviewed 338 patients with IPH that were diagnosed at the pathological consultation center of our hospital. RESULTS: The ratio of male to female patients was 1:1. Mean age at onset was 35.1 ± 16.5 years; male patients on average were 12 years younger than female patients at onset. The median duration from onset to IPH diagnosis was 12 months. In 50 patients, medication use may have been an etiological factor. The most common clinical manifestations were splenomegaly (91.3%) and hypersplenism (68.9%); 57.0% patients presented varicosis, while 25.1% patients had a history of variceal bleeding. Nodular regenerative hyperplasia was found in 22.2% liver biopsies. Among patients for whom laboratory data were available, 65.0%, 50.3%, and 71.4% patients presented leukopenia, anemia, and thrombocytopenia due to hypersplenism. Liver function was mostly in the compensated stage. Female patients showed worse leukopenia and anemia, while male patients were more likely to have abnormal serum transaminase and bilirubin levels. Sixty-seven patients received surgical or interventional treatment. CONCLUSIONS: High-quality liver biopsy, detailed clinical information, and expert pathologist are necessary for diagnosis of IPH. IPH can occur concurrently with other liver disease such as hepatitis and drug-induced liver injury. Medication appears to be an important etiological factor for IPH in China. Management approach was largely focused on treatment of portal hypertension and its complications.

High-fat, high-sugar diet induces splenomegaly that is ameliorated with exercise and genistein treatment.

OBJECTIVE: We tested the effect of exercise training and genistein treatment on splenomegaly in mice fed a high-fat, high-sugar diet (HFSD). RESULTS: Male and female C57BL6 mice fed HFSD containing 60% fat along with drinking water containing 42 g/L sugar (55% sucrose/45% fructose) for 12 weeks exhibited significant obesity, hyperglycemia, and elevated plasma IL-6 levels. This was accompanied by splenomegaly characterized by spleen weights 50% larger than mice fed standard chow (P < 0.05) with enlarged rad and white pulps. Mice fed HFSD and treated with a combination of exercise (30 min/day, 5 days/week) and genistein (600 mg genistein/kg diet) had reduced spleen weight (P < 0.05). The decrease in spleen weight was associated with a significant improvement in red-to-white pulp area ratio and plasma glucose and IL-6 (P < 0.05). Our findings indicate that reversal of splenomegaly by regular exercise and genistein treatment may be important in the clinical management of HFSD-induced obesity.

Idiopathic Portal Hypertension.

Idiopathic portal hypertension (IPH) is a rare disorder characterized by clinical portal hypertension in the absence of a recognizable cause such as cirrhosis. Laboratory tests often reveal a preserved liver function with anemia, leukopenia, and thrombocytopenia due to splenomegaly. Imaging studies reveal signs of portal hypertension, whereas liver stiffness and portal pressure values are usually normal or slightly elevated. Liver biopsy is considered mandatory in order to rule out other causes of portal hypertension, mainly cirrhosis. Liver histology may only show subtle or mild changes, and the definite diagnosis of IPH often requires an expert pathologist and a high-quality specimen. The most frequent clinical presentation is variceal bleeding. Ascites is rarely observed initially, although it may occasionally appear during follow-up. Typical histological findings associated with IPH have been described in patients without portal hypertension, probably representing early stages of the disease. Although the pathophysiology of this entity remains largely unknown, it is frequently associated with underlying immunological disorders, bacterial infections, trace metal poisoning, medications, liver circulatory disturbances, and thrombotic events. The long-term prognosis of patients with IPH, where ascites and the underlying condition are important prognostic factors, is better than in patients with cirrhosis. Treatments that modify the natural history of the disease remain an unmet need, and management of IPH is frequently restricted to control of portal hypertension-related complications.

Idiopathic portal hypertension and extrahepatic portal venous obstruction.

BACKGROUND: Idiopathic portal hypertension (IPH) and extrahepatic portal venous obstruction (EHPVO) are non-cirrhotic vascular causes of portal hypertension (PHT). Variceal bleed and splenomegaly are the commonest presentations. AIM: The present review is intended to provide the existing literature on etiopathogenesis, clinical profile, diagnosis, natural history and management of IPH and EHPVO. RESULTS: IPH and EHPVO are both characterized by normal hepatic venous pressure gradient, moderate to massive splenomegaly with preserved liver synthetic functions. While the level of block in IPH is presinusoidal, in EHPVO it is at prehepatic level. Infections, autoimmunity, drugs, immunodeficiency and prothrombotic states are possible etiological agents in IPH. Contrastingly in EHPVO, prothrombotic disorders and local factors around the portal vein are the incriminating factors. Diagnosis is often clinical, supported by simple radiological tools. Natural history is defined by episodes of variceal bleed and symptoms related to enlarged spleen. Growth failure, portal biliopathy and minimal hepatic encephalopathy are additional concerns in EHPVO. Long-term survival is reasonably good with endoscopic surveillance; however, parenchymal extinction leading to decompensation is seen in a minority of patients in both the disorders. Surgical shunts revert the complications secondary to PHT. Meso-Rex shunt has become the standard surgery in children with EHPVO. CONCLUSION: This review gives a detailed summary of these two vascular conditions of liver-IPH and EHPVO. Further research is needed to understand the pathogenesis and natural history of these disorders.

Should rituximab replace splenectomy in the management of splenic marginal zone lymphoma?

BACKGROUND: SMZL is a relatively rare low grade B-cell lymphoma, characterized usually by an indolent clinical behavior. Since there is no prospective randomized trials to establish the best treatment approach, decision on therapeutic management should be based on the available retrospective series. Based on these data, rituximab and splenectomy appear to be the most effective. Splenectomy represented the standard treatment modality until early 2000s. More than 90% of the patients present quick amelioration of splenomegaly related symptoms along with improvement of cytopenias related to hypersplenism. The median progression free survival was 8.25 years in the largest series of patients published so far, while the median 5- and 10- year OS were 84% and 67%, respectively. Responses to splenectomy are not complete since extrasplenic disease persists. Patients with heavy bone marrow infiltration, lymphadenopathy or other disease localization besides the spleen are not good candidates for splenectomy. Furthermore splenectomy is a major surgical procedure accompanied by acute perioperative complications as well as late toxicities mainly due to infections. For that reasons splenectomy is not appropriate for elderly patients or patients with comorbidities with a high surgical risk. On the other hand rituximab monotherapy displays high efficacy with minimal toxicity. Several published series have shown an ORR more than 90%, with high CR rates (∼50%). The 10-year PFS and OS were 63% and 85%, respectively in a series of 104 SMZL patients. The role of rituximab maintenance has been investigated by only one group. Based on these data, maintenance with rituximab further improved the quality of responses by increasing significantly the CR rates (from 42% at the end of induction to 71% at the end of maintenance treatment), as well as the duration of responses: 7-year PFS was 75% for those patients who received maintenance vs 39% for those who did not (p < 0.0004). However no difference in OS has been noticed between the two groups, so far. Summarizing the above data, it is obvious that Rituximab monotherapy is associated with high response rates, long response duration and favorable safety profile, rendering it as the treatment of choice in SMZL.