CD10 and BCL-6 expression in paraffin sections of normal lymphoid tissue and B-cell lymphomas

In this study the authors explored the value of immunostaining for follicular center B-cell markers, BCL-6 and CD10, in paraffin sections as a tool for the differential diagnosis of B-cell lymphomas. The cases studied comprised reactive lymphoid hyperplasia (RLH; n = 19), follicular lymphoma (FL; n = 50), low-grade mucosa-associated lymphoid tissue (MALT) lymphoma (n = 24), mantle cell lymphoma (n = 19), splenic marginal zone lymphoma (n = 13), diffuse large B-cell lymphoma (DLBCL; n = 54), Burkitt's lymphoma (BL; n = 20), nodular lymphocyte predominance Hodgkin's disease (NLPHD; n = 16), and classic Hodgkin's disease (CHD; n = 13). In RLH, CD10 and BCL-6 were expressed almost exclusively by the follicular center cells. In contrast in FL, the expression of CD10 (39/50) and BCL-6 (34/36) was seen in both follicular and interfollicular neoplastic B cells. Marginal zone/MALT lymphomas and mantle cell lymphoma were always negative. In DLBCL the expression was variable for both CD10 (21/54) and BCL-6 (39/47), with some tumors, including cases of transformed follicular lymphoma (9/10), coexpressing CD10 and BCL-6, and others expressing only BCL-6, and a small group expressing neither marker, possibly reflecting the underlying primary pathogenetic events such as the rearrangement of BCL-2 or BCL-6 genes. BL was always both CD10 and BCL-6 positive. In NLPHD the L&H cells expressed BCL-6 (11/13) but not CD10, whereas in CHD BCL-6 expression was seen in half of the cases. This study demonstrates that both CD10 and BCL-6 are reliable markers of follicular center B-cell differentiation. CD10 and BCL-6 immunostaining have an important role in differential diagnosis of FL from RLH and other low-grade B-cell lymphomas. The results also suggest that a CD10/BCL-6 expression pattern may be helpful in identifying main subsets of DLBCL. However, additional studies comparing genotype with immunophenotype are required.

Iron oxide-enhanced MR imaging of the liver and spleen: review of the first 5 years

Superparamagnetic iron oxide (SPIO) particles are a potent new class of MR contrast agents affording improved detection of hepatic and splenic neoplasms. In this report we review the development of this agent through preclinical studies and early clinical results at Massachusetts General Hospital during a 5-year investigation. SPIO particles are sequestered by normal phagocytic Kupffer cells of the reticuloendothelial system (RES) but are not retained in tumor tissue. Consequently, there is a fivefold increase in T2 relaxation between normal RES tissue and tumor, with a comparable advantage in quantitative signal-to-noise ratio, contrast-to-noise ratio, and lesion detectability in the liver and spleen on MR imaging. Increased lesion conspicuity can be exploited to decrease threshold size for lesion detection to less than 3 mm. Clinically beneficial effects occur with a variety of mildly T2-weighted spin-echo pulse sequences; gradient-echo techniques show even greater benefit after administration of SPIO. Metabolically, pharmaceutical-grade preparations are biodegradable and bioavailable, being rapidly turned over into body iron stores and incorporated into erythrocyte hemoglobin. Early dose-escalation clinical trials have identified a probable clinical dose range of 10-20 mumols Fe/kg body weight. In the United States, SPIO compounds evaluated to date are still approved for use in investigational studies only. Newer commercial formulations currently being evaluated may extend clinical safety margins.

MR imaging of the spleen: spectrum of abnormalities

The spleen has the same relationship to the circulatory system that the lymph nodes have to the lymphatic system. A wide range of diseases can affect the spleen. Pathologic conditions of the spleen can be classified into the following categories: congenital diseases (accessory spleen, polysplenia, and asplenia); trauma; inflammation (abscess, candidiasis, histoplasmosis, and sarcoidosis); vascular disorders (infarction, diseases affecting the splenic vasculature, and arteriovenous malformation); hematologic disorders (sickle cell disease and extramedullary hematopoiesis); benign tumors (cysts, hemangioma, diffuse hemangiomatosis of the spleen, and hamartoma); malignant tumors (sarcoma, lymphoma, and metastases); and other disease processes that affect the spleen diffusely (portal hypertension, Gaucher disease, and sickle cell disease) or focally (Gamna-Gandy nodules). New magnetic resonance (MR) imaging techniques have increased the role of MR imaging in detection and characterization of splenic diseases. MR imaging is an excellent tool for diagnosis and evaluation of focal lesions and pathologic conditions of the spleen.

Leukocyte common antigen--a diagnostic discriminant between hematopoietic and nonhematopoietic neoplasms in paraffin sections using monoclonal antibodies: correlation with immunologic studies and ultrastructural localization

Immunohistochemical localization of human leukocyte common antigen (LCA), a major membrane glycoprotein restricted to leukocytes, was evaluated in paraffin sections of a wide variety of hematopoietic and nonhematopoietic tissues (294 specimens) with monoclonal antibodies (PD7/26 and 2B11). In nonneoplastic tissues, LCA was identified on B and T lymphocytes, with variable immunoreactivities for plasma cells and histiocytes. By light microscopy and ultrastructurally, LCA was localized predominantly to the cell membrane and was also present focally in the cytoplasm. Myeloid cells at all stages of maturation were non-reactive, as were erythroid cells, megakaryocytes, and all non-hematopoietic tissues. Monocytes and mast cells, however, revealed membrane staining for LCA. In nearly all non-Hodgkin's lymphomas of the B- and T-cell types (74 of 80; 93 per cent), the lymphoid infiltrate was immunoreactive for LCA. In specimens from patients with Hodgkin's disease (nodular sclerosis and mixed cellularity type), rare Reed-Sternberg cells stained for LCA. Neoplastic cells were consistently immunoreactive for LCA in specimens from patients with chronic lymphocytic leukemia of the B- or T-cell type, prolymphocyte leukemia, and hairy cell leukemia. However, tissues from only three of eight cases of acute lymphoblastic leukemia were LCA-positive, with most non-reactive specimens exhibiting CALLA (J5) positivity. In cases of multiple myeloma, only minor populations of plasmacytic cells exhibited membrane staining for LCA. Nonhematopoietic neoplasms (102 evaluated), including small cell anaplastic carcinomas, amelanotic melanomas, alveolar rhabdomyosarcomas, Ewing's sarcoma, and germ cell tumors, were uniformly non-reactive. Human LCA represents an excellent cell marker for paraffin sections, to distinguish hematopoietic neoplasms, particularly of the lymphoid type, from poorly differentiated tumors of epithelial, mesenchymal, or neural derivation.

Splenosis: autotransplantation of splenic tissue

Splenosis is the autotransplantation of splenic tissue that usually follows traumatic rupture of the spleen. Generally, the splenic implants are numerous and are located within the peritoneal cavity; however, extra-abdominal splenosis does occur. The implants are rarely clinically significant and are incidental findings at autopsy or at abdominal operation, unrelated to and distant from the splenic trauma and splenectomy. Splenic implants retain their ability to function, and recurrence of a hematologic disease for which the spleen was previously removed should alter the clinician to the possibility of splenosis. The differential diagnosis includes accessory spleens, endometriosis, hemangiomas and metastatic cancer. We report three cases, two of which represent unusual complications of splenosis: a twisted pedicle of a splenic implant, which apparently caused abdominal pain, and recurrent Felty's syndrome associated with splenosis and an accessory spleen.

Canine Indolent Nodular Lymphoma

Sixty-six cases of indolent canine lymphoid proliferation were reviewed. Age ranged from 1.5 to 16 years (median 9.0 years). Dogs of 26 breeds, plus 13 of mixed breeding or unknown lineage, were represented. B-Cell lymphomas (CD79a+) predominated. Marginal zone lymphoma (MZL), the largest group, involved lymph node (33 cases) and spleen (13 cases), with both tissues involved in five of these cases. Follicular lymphoma (FL) involved lymph nodes (five cases), and mantle cell lymphoma (MCL) occurred as solitary splenic masses (three cases). Nodal CD3+ T-zone lymphomas (TZL) (10 cases), were included since they resembled late-stage MZL at the architectural level. Two cases of marginal zone hyperplasia (MZH) were included to aid in differentiation of early MZL. Clonality status was determined in 54 cases by analysis of immunoglobulin heavy chain (IGH) and T-cell antigen receptor gamma (TCRG) gene rearrangement. Clonal rearrangement of IGH was detected in 28 of 35 MZL cases (80%), four of four FL cases (100%) and three of three MCL cases (100%). Concurrent cross lineage rearrangement of TCRG was detected in six MZL and two FL cases. Clonal rearrangement of TCRG was documented in five of eight TZL cases (63%). Limited survival data obtained for 18 dogs indicated that the B-cell lymphomas (MZL, MCL, and FL) and the T-cell lymphoma (TZL) were associated with indolent behavior and long survival. Although to the authors' knowledge, the true incidence of canine indolent lymphomas is unknown, the tumors are not rare and may have been underrecognized. Recognition of their architectural features, routine application of immunophenotyping, and molecular clonality assessment should alleviate this.

Splenic marginal zone cell lymphoma

We describe four female patients with primary splenic low-grade non-Hodgkin's B-cell lymphomas with the morphology and immunophenotype of splenic marginal zone lymphocytes. The patients presented with splenomegaly, anemia, and weight loss. The bone marrow was involved in all four cases. Liver involvement was found in one patient; and in another, a CT scan revealed lymphadenopathy in the chest and abdomen. The histology of the spleen was characterized by broad concentric strands of monomorphic medium-sized lymphocytes around lymphoid follicles in one case and infiltrating follicles in two cases. Selective replacement of follicles was seen in one case. Tumor in splenic hilar lymph nodes (four cases) and liver (one case) was similar. Three patients remain well 4, 9, and 12 months, respectively, after splenectomy without further treatment. One patient who received chemotherapy died 1 year after splenectomy.

Splenic B cell lymphoma with circulating villous lymphocytes: differential diagnosis of B cell leukaemias with large spleens

The clinical, haematological, morphological and histological features of a series of 22 patients presenting with splenic lymphoma with circulating villous lymphocytes were assessed and compared with those of patients with other forms of chronic B cell leukaemia in an attempt to differentiate this condition from hairy cell leukaemia, prolymphocytic leukaemia, and chronic lymphocytic leukaemia, with which this condition has many features in common. The disease was twice as common in men than in women, with a mean (SD) age at diagnosis of 72 (9) years, and the most consistent presenting feature was massive enlargement of the spleen, which showed white and red pulp disease with a plasmacytic component. Small monoclonal bands were found in 60% of cases.

Imaging of the spleen: CT with supplemental MR examination

Splenic lesions tend to be small or infiltrating and vary in size and configuration, making detection difficult, particularly without use of an organ-specific contrast agent. The authors present a series of selected cases to show the value of computed tomography (CT) and magnetic resonance (MR) imaging in depiction of splenic disease. Six major categories are presented: (a) inflammatory disease, (b) splenic cysts, (c) infarction, (d) nonneoplastic and noninfectious diffuse splenic disease, (e) benign tumors, and (f) malignant tumors. CT attenuation of splenic tissue is homogeneous, typically measuring 40-60 HU on non-contrast material-enhanced scans. Splenic attenuation is normally 5-10 HU less than that of liver, a standard of reference used in evaluation of either hepatic or splenic disease. On T1-weighted MR images, the normal signal intensity of the spleen is less than that of hepatic tissue and slightly greater than that of muscle. On T2-weighted images, the spleen shows higher signal intensity, appearing brighter than the liver. CT is currently the choice for evaluation of the spleen; however, MR imaging may be increasingly used as newer pulse sequences and organ-specific contrast agents are developed.

Splenic marginal-zone lymphoma: a distinct clinical and pathological entity

In the World Health Organization classification system, splenic marginal-zone lymphoma (splenic MZL) is described as an indolent B-cell lymphoma, which generally presents as splenomegaly with involvement of the bone marrow and peripheral blood. Presence of disease in peripheral lymph nodes and extranodal locations is uncommon. Splenic MZL is characterised by micronodular infiltration of the spleen with marginal-zone differentiation; the immunophenotype is usually IgM+ IgD+/- cytoplasmic-Ig-/+ pan B antigens+ CD5- CD10- CD23- CD43-/+ cyclin D1-; and the most common genetic abnormalities are deletions at 7q22-7q32. Most patients with splenic MZL live for a long time but classic prognostic factors cannot distinguish between patients who are likely to have good and poor outcomes. However, immunological events, such as haemolytic anaemia and immune thrombocytopenia, or the presence of a monoclonal component, are significantly associated with shorter survival. Splenectomy is considered the first-line treatment of choice for splenic MZL; it results in only partial remission, but responses are generally sufficient for correcting cytopenia, improving quality of life, and increasing survival.

Splenic metastases: clinicopathologic presentation, differential diagnosis, and pathogenesis

CONTEXT

Splenic metastases from solid tumors, defined as parenchymal lesion, are considered exceptional. Nevertheless, the number of case reports has been increasing due to the improvement of imaging techniques and the long-term follow-up of patients with cancer. Splenic metastases occur in a context of multivisceral disseminated cancer or as a solitary lesion.

OBJECTIVE

To provide a general overview of the clinicopathologic features, differential diagnosis, and pathogenesis of splenic metastases.

DATA SOURCES

Relevant articles indexed in PubMed (National Library of Medicine) database. The search was based on the following terms: (metastasis or metastases) and spleen.

CONCLUSIONS

The most common primary sources of splenic metastasis are breast, lung, colorectal, and ovarian carcinomas and melanoma in cases of multivisceral cancer and colorectal and ovarian carcinomas in cases of solitary splenic lesion. Splenectomy can be replaced by less aggressive methods such as fine-needle aspiration or percutaneous biopsy for establishing the diagnosis of solitary splenic metastasis. The main differential diagnoses are primary lymphoma, vascular tumors, and infectious lesions of the spleen. The relative rarity of splenic metastases could be explained by anatomic factors and the inhibitory effect of the splenic microenvironment on the growth of metastatic cells. The analysis of clinical case reports suggests that solitary splenic metastases may result from the growth of an early blood-borne micrometastasis following a period of clinical latency, often several years after the diagnosis of the primary tumor.

Splenic marginal zone lymphoma: proposal of new diagnostic and prognostic markers identified after tissue and cDNA microarray analysis

Splenic marginal zone lymphoma (SMZL) is a newly recognized lymphoma type whose precise molecular pathogenesis is still essentially unknown. This hampers differential diagnosis with other small B-cell malignancies. With the aim of characterizing this tumor more comprehensively, and of identifying new diagnostic and prognostic markers, we performed cDNA microarray expression profiling and tissue microarray (TMA) immunohistochemical studies in a relatively large series of 44 SMZLs. The results were related to immunoglobulin heavy chain variable region (IgV(H)) mutational status and clinical outcome. SMZLs display a largely homogenous signature, implying the existence of a single molecular entity. Of the genes deregulated in SMZLs, special mention may be made of the genes involved in B-cell receptor (BCR) signaling, tumor necrosis factor (TNF) signaling and nuclear factor-kappaB (NF-kappaB) activation, such as SYK, BTK, BIRC3, TRAF3, and LTB. Other genes observed were SELL and LPXN, which were highly expressed in spleen, and lymphoma oncogenes, such as ARHH and TCL1. In contrast, the genes CAV1, CAV2, and GNG11 located in 7q31, a commonly deleted area, were down-regulated in the entire series. A comparison with the genes comprising the signature of other small B-cell lymphomas identified 3 genes whose expression distinguishes SMZL, namely ILF1, SENATAXIN, and CD40. Shorter survival was associated with CD38 expression, naive IgV(H) genes, and the expression of a set of NF-kappaB pathway genes, including TRAF5, REL, and PKCA.

Hepatic metastases: randomized, controlled comparison of detection with MR imaging and CT

To determine the accuracy of magnetic resonance (MR) imaging relative to computed tomography (CT) in the diagnosis of liver metastases, a randomized, controlled study was conducted of 135 subjects, including 57 with cancer metastatic to the liver, 27 with benign cysts or hemangiomas, and 51 without focal liver disease. The sensitivity of MR imaging for detecting individual metastatic deposits was 64%, significantly greater than 51% for CT (P less than .001); the difference in sensitivity for identifying patients with one or more hepatic metastases was less (82% for MR imaging vs. 80% for CT). In patients without hepatic metastases, the specificity of MR imaging was 99% versus 94% for CT. Significant differences were found between individual MR pulse sequences in detection of individual lesions. The sensitivity of both T1-weighted spin-echo (SE) (64%) and inversion-recovery (IR) (65%) pulse sequences was significantly (P less than .001) greater than either the TE (echo time) 60 msec (43%) or TE 120 msec (43%) T2-weighted pulse sequences. Overall, the accuracy of a single T1-weighted (10-minute) pulse sequence was superior to that of contrast-enhanced CT.

Abdominal lymphangioma in adults and children

BACKGROUND

Abdominal lymphangioma is a rare tumour usually classified with mesenteric and retroperitoneal cysts. This experience of abdominal lymphangiomas contrasts the differences between tumours in children and adults.

METHODS

Between 1970 and 1996, six patients had surgical resection of an abdominal lymphangioma.

RESULTS

There were three children aged 4 years or less and three adults aged 36-76 years. Two children presented with an acute abdomen and one with a rapidly enlarging abdominal girth. Lymphangiomas were located in the mesentery and gastrointestinal tract. In adults, symptoms lasted from months to years and lymphangiomas were found in the pancreas, spleen and retroperitoneum.

CONCLUSION

In this series, abdominal lymphangioma presented more acutely in children and usually involved the mesentery, whereas in adults the history was longer and the tumour was found in the retroperitoneum.

Splenic hemangiomas and hamartomas: MR imaging characteristics of 28 lesions

PURPOSE

To determine the magnetic resonance (MR) imaging features of splenic hemangiomas and hamartomas, including their pattern of dynamic contrast material enhancement.

MATERIALS AND METHODS

The appearance of 28 lesions in 18 patients was retrospectively reviewed on T2-weighted images (16 patients), unenhanced T1-weighted images (18 patients), and dynamic contrast-enhanced T1-weighted images (17 patients). Seventeen of 23 hemangiomas and all five hamartomas were proved at pathologic examination.

RESULTS

Of the 22 hemangiomas imaged with T2-weighting, 19 were hyperintense, two were isointense, and one was hypointense relative to the spleen. Dynamic gadolinium-enhanced imaging demonstrated a progressive centripetal pattern of enhancement in 19 of 22 hemangiomas. On delayed images, 19 hemangiomas demonstrated uniform enhancement. Of the five hamartomas, four were imaged with T2-weighting; three were hyperintense and one was hypointense relative to the spleen. All hamartomas demonstrated diffuse heterogeneous enhancement on images obtained early after administration of contrast material and became more uniformly enhanced on delayed images.

CONCLUSION

Splenic hemangiomas showed signal intensity characteristics and enhancement patterns similar to those described for hepatic hemangiomas. Since these features have been shown to reliably distinguish hemangiomas from other benign and malignant liver lesions, it may be reasonable to consider without histologic verification that lesions in the spleen with these imaging features represent hemangiomas.

Superparamagnetic iron oxide: enhanced detection of focal splenic tumors with MR imaging

Superparamagnetic iron oxide (AMI-25), a reticuloendothelial cell-specific contrast agent for magnetic resonance (MR) imaging, was evaluated for its ability to permit detection of splenic metastases in 18 patients. Superparamagnetic iron oxide, at a dose of 30 mumol of iron per kilogram, decreased the signal intensity of spleen from 19.5 +/- 4.8 to 3.1 +/- 2.2 (spin-echo sequence, repetition time msec/echo time msec = 1,500/42; P less than .05), without changing the signal intensity of tumor. As a result, the tumor-spleen contrast-to-noise ratio increased from 0.2 (tumor isointense relative to spleen) to 18.0 (tumor hyperintense relative to spleen). As a consequence of increased contrast, splenic tumors were detected in four of 18 patients (45 individual lesions; P less than .05), whereas nonenhanced MR imaging permitted detection of splenic lesions in only two of 18 patients (four individual lesions). Maximum tumor-spleen contrast was achieved within 60 minutes after intravenous administration. These initial clinical results indicate that MR imaging with superparamagnetic iron oxide may offer improved accuracy in the diagnosis of splenic tumors.

A pattern-oriented approach to splenic imaging in infants and children

The spleen in infants and children is commonly involved in a variety of pathologic processes. Some of these processes cause isolated splenic disease, whereas others involve the spleen as part of a systemic illness. To facilitate differential diagnosis of splenic abnormalities, a pattern-oriented approach to the imaging evaluation of the pediatric spleen was developed. With this approach, splenic anomalies are categorized as anomalies of splenic shape (clefts, notches, lobules), location (eg, wandering spleen), number (polysplenia, asplenia), or size (splenomegaly, splenic atrophy); solitary lesions (eg, cysts, lymphangiomas, hemangiomas, hamartomas); multiple focal lesions (eg, trauma, infection and inflammation, neoplasms, storage disorders); and diffuse disease without focal lesions (eg, infarction, heavy metal deposition, hemangioendotheliomas, peliosis). A variety of imaging modalities can be used in splenic assessment, including computed tomography, magnetic resonance imaging, ultrasound, and technetium-99m scintigraphy. The imaging appearance of the pediatric spleen depends on the patient's age and the modality used; however, familiarity with the spectrum of radiologic patterns of splenic involvement will facilitate correct diagnosis and prompt treatment.

Ultrasound-guided fine needle biopsy of the spleen: high clinical efficacy and low risk in a multicenter Italian study

The aim of this study was to evaluate the clinical efficacy and safety of the ultrasound-guided fine needle biopsy (UG-FNB) of the spleen in a large population of patients. We collected retrospectively the findings concerning the application of UG-FNB of the spleen from eight Italian clinical centers that utilized this technique for at least ten years. A data schedule was sent to all centers to collect information about techniques, results, and complications of UG-FNB of the spleen. We analyzed 398 biopsy procedures both on focal lesions (257 cases) and on splenic parenchyma (141 cases). The overall accuracy was 90.9% for the series as a whole, 84.9% for cytological sampling, 88.3% for microhistological sampling, and 90.3% for both cytological and histological sampling (double biopsy). Tissue core biopsy yielded better overall accuracy in patients with suspected splenic involvement by lymphoma (90.9% vs. 68.5% for cytology). The complication rate was low (no death cases, less than 1% for major complications, and 5.2% for all complications). No predictive factors were able to detect high-risk situations. The operator's skill (higher number of performed procedures) was significantly related to better overall accuracy. Conversely, the complication rate was not affected. UG-FNB of the spleen is a very effective diagnostic procedure with low risk for the patient. Aspiration cytology and core needle biopsy showed similar diagnostic yields, except for the diagnosis of splenic lymphoma, in which core needle biopsy obtained better results.

Splenomegaly in dogs. Predictors of neoplasia and survival after splenectomy

Splenomegaly confirmed by surgery or necropsy in 100 dogs was diagnosed histologically as benign neoplasia (n = 1), primary splenic malignancy (n = 59), neoplastic metastases (n = 6), and nonneoplastic disease (n = 34). Dogs with known systemic disease, such as lymphoma and mast cell tumor, that caused splenomegaly were not included in the study. Hemangiosarcoma was the most common splenic disease (43 cases). Overall mean age of the dogs was 10.7 years, the most common breed was German Shepherd dog, and 72 of the dogs weighed more than 21 kg. Dogs with anemia, nucleated red blood cells, abnormal red blood cell morphology, or splenic rupture had a significantly greater chance of having splenic neoplasia (P less than 0.002). A multivariable logistic regression analysis found that the presence of anemia and splenic rupture in dogs with splenomegaly was up to 69% accurate in predicting presence of splenic neoplasia. After splenectomy, the median survival time of dogs with splenic neoplasia was 13 weeks. For dogs with nonneoplastic splenomegaly it was at least 36 weeks.

Perfluoroctylbromide: a liver/spleen-specific and tumor-imaging ultrasound contrast material

The effect of perfluoroctylbromide (PFOB) on liver and tumor echogenicity was evaluated in rabbits. The echogenicity of the kidney, which is not affected by PFOB, was used as the basis for comparison in the liver studies. For the liver echogenicity study, sonography was performed on four rabbits, two with PFOB and two without PFOB, and four rabbits prior to and following the intravenous administration of 5 ml/kg PFOB. All livers were equal to or less echogenic than kidney in the control animals. All livers became more echogenic than kidney two days after administration of PFOB. The effect of PFOB on tumor echogenicity was evaluated in 18 rabbits with VX2 tumor implanted in the liver. Ultrasound studies of all rabbits were performed by the same physician before and two days after half the rabbits had received PFOB (5 ml/kg intravenously). The reviewers correctly identified all rabbits that received PFOB by visualization of an echogenic rim around the hepatic tumors.

Hemangioma of the spleen: presentation, diagnosis, and management

Splenic hemangioma is a rare disorder but remains the most common benign neoplasm of the spleen. It often has a latent clinical picture; however, spontaneous rupture has been reported to occur in as many as 25% of this patient population.1 Treatment most often consists of splenectomy. This report reviews an 8-year experience with splenic hemangioma at Mayo Clinic. Thirty-two patients were identified with SH during the 8-year study period. The average age was 63 years (range 23 to 94 years) with 17 women and 15 men. Six patients presented with symptoms potentially related to the SH. The remainder (80%) were asymptomatic, and the SH was discovered incidentally during evaluation for other disorders. A mass or palpable spleen was appreciated in only four patients (12.5%). SHs ranged in size from 0.3 to 7 cm maximum diameter. A diagnosis of SH was made in 11 patients based on the findings of a splenic mass on computed tomography or ultrasound. Each of these SHs was < or =4 cm. Three of the 11 patients had multiple SHs. All 11 patients were managed successfully with observation. All but one of the patients remains asymptomatic, and no complications have developed during follow-up (range 0.6 to 7 years, mean 2.9 years). The diagnosis of splenic hemangioma was made at the time of surgery in the remaining 21 patients (65%). Splenectomy was performed for suspicion of primary or secondary splenic pathology. There were no instances of spontaneous rupture of the SH. Small splenic lesions, which meet the radiologic criteria for hemangiomas, may be safely observed.

The diagnosis of splenic lymphoma by MR imaging: value of superparamagnetic iron oxide

This study was designed to evaluate superparamagnetic iron oxide (AMI-25) as a contrast agent for MR to distinguish normal spleens from those diffusely infiltrated by lymphoma. As diffuse splenic involvement lacks visible tumor-tissue boundaries, signal-intensity measurements of spleens were used as a diagnostic criterion in 33 patients (lymphoma, n = 8; benign splenomegaly, n = 5; normal subjects, n = 20). Unenhanced MR images were insensitive (four of eight patients) and nonspecific (20 of 25 patients) in the diagnosis of lymphoma. After injection of superparamagnetic iron oxide (40 mumol Fe/kg), lymphomatous spleens showed a significantly higher signal intensity (p less than .05) than did normal spleens or spleens enlarged by benign disease (hepatic cirrhosis, n = 4; spherocytosis, n = 1). Changes in splenic MR signal intensity unambiguously identified eight of eight lymphomatous spleens and 25 of 25 normal or enlarged spleens that did not contain lymphoma. Phagocytosis of superparamagnetic iron oxide in lymphomatous spleens is reduced because of diffuse displacement of splenic macrophages by lymphoma cells and/or by immunologic suppression of macrophage activity. Our results suggest that superparamagnetic iron oxide (AMI-25) can improve the accuracy of MR imaging in the diagnosis of splenic lymphoma. With further development, this noninvasive technique may reduce the need for diagnostic splenectomy in lymphoma patients.

Intrasinusoidal bone marrow infiltration: a possible hallmark of splenic lymphoma

A particular type of lymphomatous bone marrow infiltration defined as intrasinusoidal and occurring in seven patients with splenomegaly and mild to moderate thrombocytopenia is reported. Immunocytochemistry highlighted the intrasinusoidal pattern and showed a mature B-cell phenotype. Four patients underwent splenectomy and a diagnosis of splenic marginal cell lymphoma was made. The disease course seems to be chronic and quite indolent. All patients are alive and well; follow-up ranges from 2 to 42 months. The value of bone marrow biopsy as a primary diagnostic tool in splenic marginal zone lymphomas is discussed.