Pulmonary light-chain deposition disease: CT and pathology findings in nine patients.

AIM: To review the clinical features of nine patients with pulmonary light-chain deposition disease (LCDD) and record their high-resolution CT (HRCT) and histopathological findings. MATERIALS AND METHODS: Patients with a diagnosis of LCDD on lung biopsy specimen were retrospectively identified. The HRCT characteristics of nodules, cysts, and ancillary findings; change at follow-up; and histopathological findings were documented. RESULTS: Features common to all nine cases were thin-walled cysts. In seven cases, vessels traversing the cysts were identified. The majority of patients (8/9) had at least one pulmonary nodule. There was no zonal predominance of either cysts or nodules. The disease appeared stable in the majority of cases with no serial change in HRCT appearances (5/6 cases with follow-up data, mean duration 29 months). CONCLUSION: To the authors' knowledge, this is the largest series of pulmonary LCDD patients in the literature, and the first systematic assessment of HRCT findings. Pulmonary cysts are a unifying feature, usually with pulmonary nodules, and serial change on HRCT is unusual.

A20 deletion is associated with copy number gain at the TNFA/B/C locus and occurs preferentially in translocation-negative MALT lymphoma of the ocular adnexa and salivary glands.

The genetic basis of MALT lymphoma is largely unknown. Characteristic chromosomal translocations are frequently associated with gastric and pulmonary cases, but are rare at other sites. We compared the genetic profiles of 33 ocular adnexal and 25 pulmonary MALT lymphomas by 1 Mb array-comparative genomic hybridization (CGH) and revealed recurrent 6q23 losses and 6p21.2-6p22.1 gains exclusive to ocular cases. High-resolution chromosome 6 tile-path array-CGH identified NF-kappaB inhibitor A20 as the target of 6q23.3 deletion and TNFA/B/C locus as a putative target of 6p21.2-22.1 gain. Interphase fluorescence in situ hybridization showed that A20 deletion occurred in MALT lymphoma of the ocular adnexa (8/42=19%), salivary gland (2/24=8%), thyroid (1/9=11%) and liver (1/2), but not in the lung (26), stomach (45) and skin (13). Homozygous deletion was observed in three cases. A20 deletion and TNFA/B/C gain were significantly associated (p<0.001) and exclusively found in cases without characteristic translocation. In ocular cases, A20 deletion was associated with concurrent involvement of different adnexal tissues or extraocular sites at diagnosis (p=0.007), a higher proportion of relapse (67% versus 37%) and a shorter relapse-free survival (p=0.033). A20 deletion and gain at TNFA/B/C locus may thus play an important role in the development of translocation-negative MALT lymphoma.

Chlamydiae and Mycoplasma infections in pulmonary MALT lymphoma.

Chlamydia pneumoniae, Chlamydia trachomatis and Chlamydia psittaci were detected at low frequencies (<20%) among 69 pulmonary mucosa-associated lymphoid tissue (MALT) lymphomas, 30 other lymphoproliferative disorders (LPD) and 44 non-LPD. The incidence of individual Chlamydiae was generally higher in MALT lymphoma than non-LPD, although not reaching statistical significance. Mycoplasma pneumoniae DNA was not detected.

The appearances of oesophageal carcinoma demonstrated on high-resolution, T2-weighted MRI, with histopathological correlation.

This paper describes the spectrum of imaging features of oesophageal adenocarcinoma seen using high-resolution T2-weighted (T2W) magnetic resonance imaging (MRI). Thirty-nine patients with biopsy-proven oesophageal adenocarcinoma were scanned using an external surface coil. A sagittal T2W sequence was used to localise the tumour and to plan axial images perpendicular to the tumour. Fast spin-echo (FSE) T2W axial sequence parameters were: TR/TE, 3,300-5,000 ms/120-80 ms; field of view (FOV) 225 mm, matrix 176x512(reconstructed) mm to 256x224 mm, giving an in-plane resolution of between 1.28x0.44 mm and 0.88x1.00 mm, with 3-mm slice thickness. Thirty-three patients underwent resection and the MR images were compared with the histological whole-mount sections. There were four T1, 12 T2, and 17 T3 tumours. The T2W high-resolution MRI sequences produced detailed images of the oesophageal wall and surrounding structures. Analysis of the imaging appearances for different tumour T stages enabled the development of imaging criteria for local staging of oesophageal cancer using high-resolution MRI. Our study illustrates the spectrum of appearances of oesophageal cancer on T2W high-resolution MRI, and using the criteria established in this study, demonstrates the potential of this technique as an alternative non-invasive method for local staging for oesophageal cancer.

Pathological assessment of rectal carcinoma after preoperative therapy.

Increasingly neoadjuvant therapy is being used to improve outcomes in patients with rectal carcinoma in which the circumferential resection margins are considered to be at risk for involvement if primary surgery were to be undertaken. Assessment of the response to this approach relies on radiological examination, particularly magnetic resonance imaging (MRI) studies. Following definitive surgery, careful histological examination allows full assessment of the tumour response to these preoperative approaches. Histological examination requires careful fixation, examination of the entire area occupied by the tumour prior to down-staging and careful lymph node harvesting. Adequate fixation helps in these endeavours and the lymph node harvest appears to be unaffected by neoadjuvant chemo- or radiotherapy. Correlation between preoperative assessment of response by MRI and the subsequent histological assessment is close, but the presence of isolated residual neoplastic glands in a post-treatment fibrotic stroma is impossible to detect prior to resection. The clinical significance of these microscopic foci remains uncertain, particularly in view of the prolonged tumour doubling time associated with colorectal adenocarcinoma. The preoperative discussion with the patient requires a synthesis of their own scan results and the experience of detailed clinico-pathological studies. While MRI frequently predicts the presence or absence of residual tumour the possibility of under-staging remains and this is of crucial importance if a 'watch and wait' policy is to be adopted following apparent complete clinical and radiological remission. The significance of potential residual microscopic disease in patients with apparent radiological complete remission needs further investigation but may need to be interpreted in individual patients in the context of overall life-expectancy.

Chlamydia psittaci is variably associated with ocular adnexal MALT lymphoma in different geographical regions.

Infectious agents play a critical role in MALT lymphoma development. Studies from Italy showed Chlamydia psittaci infection in 87% of ocular adnexal MALT lymphomas and complete or partial regression of the lymphoma after C. psittaci eradication in four of nine cases. However, C. psittaci was not demonstrated in ocular adnexal MALT lymphomas from the USA. This study was thus designed to investigate further the role of C. psittaci, and other infectious agents commonly associated with chronic eye disease, in the development of ocular adnexal MALT lymphoma. The presence of C. psittaci, C. trachomatis, C. pneumoniae, herpes simplex virus 1 and 2 (HSV1, HSV2), and adenovirus 8 and 19 (ADV8, ADV19) was assessed separately by polymerase chain reaction in 142 ocular adnexal MALT lymphomas, 53 non-marginal zone lymphomas, and 51 ocular adnexal biopsies without a lymphoproliferative disorder (LPD), from six geographical regions. C. psittaci was detected at similar low frequencies in non-LPD and non-marginal zone lymphoma groups from different geographical regions (0-14%). Overall, the prevalence of C. psittaci was significantly higher in MALT lymphomas (22%) than in non-LPD (10%, p=0.042) and non-marginal zone lymphoma cases (9%, p=0.033). However, the prevalence of C. psittaci infection in MALT lymphoma showed marked variation among the six geographical regions examined, being most frequent in Germany (47%), followed by the East Coast of the USA (35%) and the Netherlands (29%), but relatively low in Italy (13%), the UK (12%), and Southern China (11%). No significant differences in the detection of C. pneumoniae, C. trachomatis, HSV1, HSV2, ADV8, and ADV19 were found between lymphomas and controls from different geographical regions. In conclusion, our results show that C. psittaci, but not C. pneumoniae, C. trachomatis, HSV1, HSV2, ADV8 or ADV19, is associated with ocular adnexal MALT lymphoma and that this association is variable in different geographical areas.

Centrocytoid plasma cells of the germinal center.

Germinal centers within the lymph node follicles are T-cell-dependent, antigen-driven B-cell proliferations that develop from the rapid clonal expansion of a few founder cells. The end results of this B-cell expansion are memory B cells or plasma cells. Two morphologic forms of plasma cell can be recognized in the germinal center: classic plasma cells, characterized morphologically by peripherally clumped arrangement of nuclear chromatin, and cells with a nuclear morphology more resembling that of the centrocytes, which the authors have termed "centrocytoid plasma cells." In this study the authors examined the distribution and immunohistochemical characteristics of these two populations of germinal center plasma cells. The centrocytoid plasma cells were arranged in a band stretching from the junction of the dark and light zone to the periphery of the germinal centers, while the classic plasma cells were mainly present at the germinal center periphery. Both marked with CD38, CD138, and VS38c, recognized markers for plasma cells; however, EMA and CD31 were present only in the classic form of plasma cell. The proliferation marker Ki67 was present in less than 1% of the cells labeling with CD138. Others have demonstrated Ki67 in 50% of the cells labeled with Blimp-1, which is consistent with Blimp-1 appearing earlier than CD138 in ontogeny. CD10 is co-expressed with CD138 in about 10% of cells and CD45 with CD138 in about 5% of cells. Their topographic features, together with the progressive acquisition of plasma cell markers, suggest that the centrocytoid plasma cells may be the precursors of the classic plasma cells. Of note, both the forms of plasma cell were absent in follicles of follicular lymphoma, which supports the concept that in this disease, lymphocytes fail to differentiate and mature beyond the centrocyte stage.

Richter's transformation of chronic lymphocytic leukemia. The possible role of fludarabine and the Epstein-Barr virus in its pathogenesis.

Transformation of CLL into a large cell lymphoma has an incidence of 3-5%. We have studied 101 cases of CLL treated with fludarabine over a 10-year period (1990-2000) and observed a 12% incidence of transformation. In six of 12 patients, transformation was documented within 4 months following treatment with fludarabine. Pathological material, available in nine cases, was investigated for latent EBV by staining for LMP-1 by immunohistochemistry and EBERs-1 and 2 by in situ hybridisation. LMP-1 and EBERs were demonstrated in three of the nine samples. In two cases there was a different pattern of immunoglobulin gene rearrangement in the transformed cells assessed by PCR (FR3 fragment) compared to the original CLL clone. One of these two cases showed evidence of latent EBV. The other seven cases, of which two were EBV positive, showed identical pattern of Ig gene rearrangement in both the CLL and the transformed cells. We suggest that the relatively high incidence of transformation in this series may be due to immunosuppression mainly related to fludarabine, although other agents and prior therapies may have also contributed.

A comparison of flow cytometry, bone marrow biopsy, and bone marrow aspirates in the detection of lymphoid infiltration in B cell disorders.

AIMS: To evaluate the diagnostic value of bone marrow aspirates, trephine biopsies (BMB), and flow cytometry (FC) in the assessment of bone marrow infiltration in chronic lymphoid disorders. METHODS: Investigations were carried out in 110 diagnostic and follow up specimens from B cell disorders, namely: chronic lymphocytic leukaemia (CLL; 65), non-Hodgkin's lymphoma (NHL; 39), and hairy cell leukaemia (HCL; 6). A selected panel of monoclonal antibodies was used both for FC and immunohistochemistry. RESULTS: In CLL there was agreement between the three investigations in 71% of samples and in 88% when only FC and BMB were compared. In nine of 65 samples, FC and BMB were positive, although the aspirate was reported as negative. Four BMB negative samples had minimal residual disease (MRD) detected by FC, whereas two samples were positive both on BMB and aspirate but showed no evidence of disease on FC. In NHL, there was agreement between the three investigations in 22 of 39 cases, and in 27 of 39 cases there was agreement between FC and BMB. In eight of 39 NHL cases, FC was negative but the BMB was either positive (five) or uncertain (three), whereas in three of 39, FC was positive but BMB was either negative (one) or uncertain (two). In three of five uncertain BMB, no clonal population was detected by the polymerase chain reaction, whereas in the remaining two cases the nodular aggregates disappeared on further sectioning. CONCLUSIONS: Both BMB and FC are better than bone marrow aspirates for the detection of infiltration in B cell disorders. FC might be slightly more sensitive than BMB to detect MRD in CLL, whereas BMB may be slightly better than FC in NHL.

Immunohistochemical markers in the differentiation of thymic and pulmonary neoplasms.

AIMS: The histopathological features of some thymic neoplasms overlap with those of pulmonary squamous and large-cell undifferentiated carcinomas, and identification of the primary site may be difficult on routine staining. We have assessed a panel of antibodies that may help to distinguish between neoplasms from these two sites. METHODS AND RESULTS: Antibodies identifying cytokeratin 7 (CK7), CD5, CD10, CD1a and thyroid transcription factor-1 (TTF-1) were applied to a series of 20 thymic neoplasms (thymic carcinomas, atypical thymomas and thymomas), 10 primary squamous cell carcinomas of the lung and 10 large-cell undifferentiated carcinomas of the lung. Staining for TTF-1 was positive in 3/10 large-cell undifferentiated carcinomas, but negative in all other tumours. CD5 showed strong membranous staining in 3/6 thymic carcinomas and 1/14 thymomas, but only focal staining in 1/20 pulmonary carcinomas. CD1a was consistently positive in thymic lymphocytes in both typical and atypical thymomas, but only focally in 1/6 thymic carcinomas. CD1a stained dendritic cells in 7/20 pulmonary carcinomas, but did not stain lymphocytes. Staining for CK7 and CD10 did not aid in differentiating between a pulmonary or thymic origin of the tumour. CONCLUSION: Staining for TTF-1, CD5 and CD1a have potential use in distinguishing between pulmonary and thymic neoplasms.

Relative distribution of tumour cells and reactive cells in follicular lymphoma.

Follicular lymphoma is the most common low-grade B-cell lymphoma. It is characterized by at least a partial follicular growth pattern in the majority of cases, by the morphological resemblance of the tumour cells to follicle centre centroblasts and centrocytes, and by the distinctive expression of Bcl-2 protein as a consequence of a translocation between chromosomes 14 and 18, resulting in the juxtaposition of Bcl-2 and the immunoglobulin heavy chain locus. It is not known whether the follicular growth pattern of follicular lymphoma is a consequence of properties of the tumour cells, or whether the tumour cells invade and gradually occupy a niche generated by a normal T-cell-dependent B-cell response. This study has identified cases of follicular lymphoma in which the tumour cells are apparent within a normal reactive germinal centre background. The reactive background has been investigated in these cases and also in cases showing a more characteristic appearance, in which entire malignant follicles appear to be Bcl-2-positive, as assessed by microdissection and analysis of clonality by the polymerase chain reaction (PCR). A reactive oligoclonal background was observed in all cases studied, characteristic of a normal follicle centre response. These data suggest that the progression of follicular lymphoma is dependent on the normal germinal centre microenvironment. Disruption of this dependence might be considered as a novel therapeutic strategy.

Transformation of T-cell large granular lymphocyte leukaemia into a high-grade large T-cell lymphoma.

We describe a case of T-cell large granular lymphocyte (LGL) leukaemia that transformed into a large-cell T-cell lymphoma 11 years from diagnosis. A 29-year-old asymptomatic female presented in 1989 with lymphocytosis, neutropenia and mild bone marrow infiltration. The circulating cells were LGL with a CD2+, CD3+, CD8+, CD4-, CD16+, CD56+, CD57- phenotype. In August 2000, she developed fever, a large submandibular mass and hepatosplenomegaly. Biochemistry showed abnormal liver function tests and raised lactate dehydrogenase (LDH) levels. A serological screen for Epstein-Barr virus, cytomegalovirus, human T-lymphotropic virus-I, human herpes virus (HHV)-6 and HHV-7 was negative. Histology of the mass was consistent with the diagnosis of peripheral T-cell lymphoma composed of large cells, and immunohistochemistry showed that the lymphoma cells had a phenotype identical to the mature LGL. Molecular analysis with the polymerase chain reaction (PCR) demonstrated rearrangement of the T-cell receptor (TCR) gamma-chain gene with a band of identical size in both bone marrow mature LGL and lymph node cells. The patient was treated with CHOP (cyclophosphamide, vincristine, doxorubicin and prednisolone), resulting in the disappearance of the mass and improvement of the hepatosplenomegaly, LDH and liver abnormalities. She underwent splenectomy, and spleen histology showed involvement by T-cell LGL leukaemia with no evidence of transformation. This case illustrates that transformation or Richter syndrome may occur in a minority of patients with T-cell LGL leukaemia, a disease that has a benign clinical course in most cases. This is the first case documented by molecular methods of the transformation of the pre-existing clone.

Hodgkin's disease with an intrasinusoidal pattern of infiltration. A report of two cases.

The histological distinction between Hodgkin's disease (HD) and anaplastic large cell lymphoma (ALCL) may be difficult but is important as the two conditions have different clinical behaviours, prognoses and responses to therapy. Morphological appearances that have been emphasised as favouring the diagnosis of ALCL rather than HD include the identification of neoplastic cells permeating sinusoidal spaces. We document two cases of Hodgkin's disease with classical morphological and immunohistochemical features of nodular-sclerosis subtype (HDNS) but with striking sinusoidal involvement by neoplastic cells. In each case, the CD30 positive/CD15 positive immunophenotype of the neoplastic cells was characteristic of HD without expression of any of the other antigens normally associated with ALCL. HD is generally considered to be a morphological diagnosis and, in those laboratories in which it is not possible to use wide panels of antibodies for the confirmation of the diagnosis, the identification of sinusoidal infiltration by the neoplastic cells in HD may lead to the mistaken impression of ALCL.

Clone-specific PCR reveals wide dissemination of gastric MALT lymphoma to the gastric mucosa.

The development of low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma is closely associated with Helicobacter pylori infection. Despite its indolent clinical course and prolonged localization to the site of origin, the lymphoma frequently presents with multifocal lesions. However, the true extent of tumour involvement in the gastric mucosa is unclear, since reactive appearing lymphocytic infiltrates are always present and could contain tumour cells that are not readily identifiable on cytological grounds. Gastrectomy specimens of four MALT lymphoma cases were studied by microdissection and clone-specific polymerase chain reaction (CS-PCR) and of a further case with t(1;14)(p22;q32) by immunohistochemistry for BCL10 protein, which acted as a tumour marker for tumour cells carrying the translocation. CS-PCR revealed that tumour cells were commonly present in histologically non-lymphomatous lymphocytic infiltrates microdissected from areas well separated from tumour lesions. Tumour cells were also frequently found in infiltrates microdissected from the resection margins. These findings were reinforced by direct identification of tumour cells, as recognized by strong BCL10 nuclear staining, in non-lymphomatous lymphocytic infiltrates in the case with t(1;14)(p22;q32). The results show that gastric MALT lymphoma disseminates widely within the gastric mucosa without necessarily forming diagnostic lesions.