Biomedical subjects

M Mollejo

Publications and source records attributed to M Mollejo.

15 recordsLinked to original sources

PubMed1998

A marginal zone pattern may be found in different varieties of non-Hodgkin's lymphoma: the morphology and immunohistology of splenic involvement by B-cell lymphomas simulating splenic marginal zone lymphoma.

AIMS: Splenic marginal zone lymphoma (SMZL) is characterized by a micronodular infiltrate of the splenic white pulp, centred on pre-existing follicles, with a peripheral rim of 'marginal' zone B-cells, always accompanied by a variable degree of red pulp infiltration. These histological features can be closely mimicked by a variety of other small B-cell lymphomas when they involve the spleen, which makes recognition of SMZL difficult. We therefore have compared the histopathological and immunohistochemical features of other non-Hodgkin's lymphoma (NHL) types with those of SMZL. METHODS AND RESULTS: We selected cases of splenic involvement by different types of B-cell lymphoma, including mantle cell lymphoma (MCL), follicular lymphoma (FL), immunocytoma (IM) and lymphocytic lymphoma (B-CLL). A micronodular pattern and marginal zone differentiation were both found to be frequently present in FL and MCL, and with lesser frequency in IM and B-CLL. The main morphological feature useful for differential diagnosis was the cytological composition of the white pulp tumoral nodules. SMZL is distinguished by characteristic dimorphic cytology, different from the monomorphic cytology of MCL, and the distinctive mixture of centroblasts and centrocytes which is the rule in FL. B-CLL could also be identified on the basis of the polymorphic cytology including small lymphocytes and prolymphocytes, whereas cases diagnosed as IM show prominent plasmacytic differentiation, lacking the features of the other lymphoma types. Immunohistochemistry was particularly useful for the differential diagnosis. Thus the recognition of MCL was facilitated by the identification of cyclin D1 and CD43 reactivity, while FL could be recognized by the lack of IgD expression or the distinctive pattern of Ki67 staining found in SMZL. B-CLL cells were CD23+, CD43+. CONCLUSION: The results of this study provide morphological and immunohistological information useful in the recognition of the different varieties of NHLs when involving the spleen and the differential diagnosis of SMZL.

Adult↗

PubMed1998

Absence of cyclin D1 protein expression in splenic marginal zone lymphoma.

Splenic marginal zone lymphoma (SMZL) is a recently recognized primary splenic lymphoma. SMZL can be associated with peripheral lymphocytosis, in which some cells have a villous morphology (splenic lymphoma with villous lymphocytes [SLVL]). Several recent studies suggested involvement of the bcl-1 locus and/or the cyclin D1 gene, located on chromosome 11q, in SMZL/SLVL. Translocation t (11;14) is associated with rearrangement of the bcl-1 locus and overexpression of the cyclin D1 gene. Both the translocation and cyclin D1 protein expression are characteristic of mantle cell lymphoma (MCL) and are rare in other lymphoid neoplasms; thus, their detection is useful in the diagnosis of MCL. Because the differential diagnosis of low-grade lymphoma in the spleen can be difficult, it is important to assess the frequency of cyclin D1 expression in SMZL to determine its usefulness in differential diagnosis from MCL. We analyzed the expression of cyclin D1 nuclear protein in paraffin sections using an immunoperoxidase technique in 17 cases diagnosed as SMZL. In eight cases, the presence of cyclin D1 mRNA was also assessed by Northern blot analysis. None of the 17 cases of typical SMZL showed expression of cyclin D1 mRNA or protein. In contrast, four cases used as controls showed either expression of cyclin D1 protein or mRNA or both. We conclude that assessment of cyclin D1 protein expression can be useful in distinguishing SMZL from MCL involving the spleen.

Aged↗

PubMed1997

Frequent involvement of chromosomes 1, 3, 7 and 8 in splenic marginal zone B-cell lymphoma.

We have studied 19 cases of splenic marginal zone B-cell lymphoma (SMZBCL) combining cytological features, conventional cytogenetics, and in situ hybridization (ISH) techniques. A clonal chromosome abnormality was found in 11/19 patients (58%). The more frequent recurrent abnormalities were: del(3), del (7q), and involvement of chromosomes 1, 3, 7 and 8. No patient showed the translocation t(11;14)(q13;q32). An outstanding finding was the low incidence of trisomy 3 (36%) compared to patients with MALT lymphoma. These findings support the interpretation that SMZBCL is a distinct lymphoproliferative disorder.

Chromosome Aberrations↗

PubMed1997

Lymph node involvement by splenic marginal zone lymphoma: morphological and immunohistochemical features.

Splenic marginal zone lymphoma (SMZL) has recently been proposed as a distinctive type of low-grade B-cell lymphoma. Although there is general agreement that this entity exists, its precise definition is blurred by uncertainty in differential diagnosis from other low-grade B-cell lymphomas. There is even more uncertainty as to the histology of splenic hilar and peripheral lymph nodes involved by SMZL. We therefore reviewed the histological and immunohistochemical features of 19 of these lymph nodes (14 hilar and five peripheral) from 14 cases of classical SMZL and compared them with the features of lymph nodes involved by other B-cell lymphomas. The morphology and immunohistology of the lymph nodes resemble those found in the white pulp of the spleen, showing a distinctive pattern, different from that which is observed in other B-cell lymphomas. In these cases, the overall architecture of the lymph nodes is effaced and replaced by a nodular infiltrate, although the sinuses are preserved in most hilar lymph nodes. Some of the nodules contain a central reactive follicular center, around which there is a broad zone of small lymphocytes. In other cases, the central area is partially infiltrated or, more commonly, totally replaced by these small lymphocytes, which in the periphery of the nodules showed a pale, slightly larger cytoplasm. Scattered nucleolated blasts are present, largely confined to the periphery of the nodules. The tumoral cells express immunoglobulin (Ig)D, IgM, and Ig light chain restriction and show a low proliferation fraction. These findings confirm that SMZL is a real entity, and not merely a morphological pattern of splenic infiltration by different types of low-grade B-cell lymphoma.

Adult↗

PubMed1996

[Bladder carcinosarcoma. A new case].

Vesical carcinosarcoma is a very poor prognosis, infrequent tumour normally presenting with haematuria and for which the only treatment available is radical cystectomy. Here we present a new case of this tumour in a 61 year-old male with a brisk evolution to death.

Carcinosarcoma↗

PubMed1995

Splenic marginal zone lymphoma: a distinctive type of low-grade B-cell lymphoma. A clinicopathological study of 13 cases.

The recognition and classification of the different varieties of splenic low-grade B-cell lymphomas have been hampered by the rarity of histological studies of surgical splenectomy specimens of B-cell lymphoma. In an effort to characterize the recently described splenic marginal zone lymphoma (SMZL), we conducted a survey of 13 patients with this type of tumor using the criteria defined by Schmid for its recognition (Schmid et al., Am J Surg Pathol 1992;16:455-66). Primary splenic high-grade lymphomas, T-cell lymphomas, and secondary infiltration by other recognized low-grade B-cell lymphomas, with the exception of splenic lymphoma with villous lymphocytes, were excluded. This selection gave rise to a homogeneous group of tumors with similar clinical, histological, immunohistochemical, and molecular features. Our study showed the critical parameters for their recognition to be morphological, including macroscopic micronodularity and the constant presence of white- and red-pulp infiltration, marginal zone pattern, and plasmacytic differentiation. No t(14;18) or PRAD-1/cyclin D1 overexpression was detect able in any case. Clinically, the tumors were widespread with a protracted evolution. Nodal infiltration by SMZL in our cases was morphologically similar to monocytoid B-cell lymphoma. SMZL could constitute the largest group of primary splenic malignant lymphomas, partially overlapping with splenic lymphoma with villous lymphocytes. Specific molecular markers for SMZL have yet to be defined. Because of the limited number of cases, the question of therapy for this group of lymphomas must remain open for the future.

Aged↗

PubMed1994

Waldeyer ring lymphomas. A clinicopathological study of 79 cases.

Waldeyer ring lymphomas belong to a category of tumours which has not yet been fully defined. Their relation to mucosa-associated lymphoid tissue (MALT) and other extranodal lymphomas remains largely unknown. We performed a clinicopathological retrospective study of 79 patients, and compared them with a series of MALT and nodal lymphomas. Tumours from the nasopharynx and palatine tonsil showed similar histological profiles, with a predominance of large B-cells. Centroblastic lymphomas constituted the largest group (n = 45), followed by those of centrocytic type (9) with smaller groups of centroblastic-centrocytic (5) and Hodgkin's lymphomas (2). Three monocytoid B-cell lymphomas were identified. Only one case could be classified as MALT lymphoma. The frequency of bcl-2 expression in large B-cell tumours of Waldeyer's ring has an intermediate range between large B-cell lymphomas occurring in mucosal and nodal locations. Epitheliotropism was present in all low-grade cases, and was therefore not a useful marker in the identification of potential MALT lymphomas in contrast with other mucosal sites. Comparative survival studies showed significant overall differences between Waldeyer ring lymphomas, MALT and nodal cases. These disappeared after taking stage and histological grade into account. We conclude that Waldeyer ring lymphomas show distinctive features, mainly in terms of histological distribution and immunophenotype. The key factor determining their behaviour could be their different spreading capability. These findings suggest that extranodal lymphomas are heterogeneous, and indicate the need for additional efforts to clarify this.

Adolescent↗

PubMed1994

Monocytoid B cells. A comparative clinical pathological study of their distribution in different types of low-grade lymphomas.

Neoplastic monocytoid B-cells (MBCs) are present in different amounts in several types of non-Hodgkin's lymphomas (NHLs), including monocytoid B-cell lymphoma (MBCL), splenic marginal zone lymphoma (SMZL), mucosa-associated lymphoid tissue (MALT) low-grade B-cell lymphomas, and follicular centroblastic-centrocytic (CB-CC) lymphomas. In an attempt to clarify the relationships between different groups of tumors with a significant monocytoid component, we studied six primary lymph node MBCL, three SMZL, seven MALT lymphomas, and four CB-CC with monocytoid differentiation. Their clinical, morphological, immunohistochemical and molecular features were compared. The results show wide overlapping between MALT and MBCL in terms of morphology, immunophenotype, and molecular features. Follicular colonization was a characteristic finding in both groups. Some MBCL revealed mucosal involvement during the course of the disease, suggesting a possible MALT origin. Our data support the suggestion that the use of the term MBCL should be discontinued in cases with mucosal involvement, as they are probably examples of lymph node involvement brought about by MALT lymphomas. Although SMZL have some overlapping features with MBCL and MALT lymphomas, some of the clinical and morphological specific findings justify their distinction from the other groups. The CB-CCs with monocytoid differentiation frequently harbored t(14;18), lacking any significant differentiating features from conventional follicular CB-CC lymphomas. Additional studies are needed to define the molecular features of MBCL and other marginal zone tumors.

Adult↗

PubMed1993

[Thromboangiitis obliterans (Buerger's disease). Study of 41 cases].

BACKGROUND: The aim of this study was to know the prevalence, clinical and immunological characteristics and evolution of thromboangiitis obliterans. METHODS: Between 1982-1990 41 cases of thromboangiitis obliterans were diagnosed from among 373,899 patients registered (11/100,000) according to the clinical and arteriographic criteria. Of these 41 cases 40 were males with mean age 36 +/- 7 years (mean +/- SD) with only two cases being over 45 years of age. In 40 cases was followed for 44 +/- 29 months (mean +/- SD). RESULTS: All the patients had ischemia of the lower limbs, 34% of the upper limbs, 39% superficial thrombophlebitis, 53% Raynaud's phenomenon, 5% mesenteric ischemia, and 7% myocardial infarction. In 30 symptomatic patients anticardiolipin antibodies were determined and one patient was positive for IgG antibodies. In the 23 patients in whom HLA and anticollagen antibody studies were performed a significant increase was found in HLA-B35, HLA-B40 and type VI denaturalized anticollagen antibodies compared to controls. In general the evolution was progressive when the patients continued smoking and favorable when tobacco was given up except in 2 cases who stopped smoking and in whom the disease progressed and death occurred. The total number of patients who died during follow up was 3 (7%), 2 due to mesenteric ischemia and the third during i.v. infusion of PGE1. CONCLUSIONS: The results demonstrate that thromboangiitis obliterans is a rare disease in Spain. The involvement of visceral arteries is not very infrequent with worse prognosis when the mesenteric arteries are involved. There is a significant increase of determined HLA antigens and anticollagen antibodies in the patients with thromboangiitis obliterans.

Adult↗

PubMed1992

P53 protein expression in lymphomas and reactive lymphoid tissue.

P53 is a tumour suppressor gene, located in the short arm of chromosome 17, which encodes for a nuclear protein involved in the control of cellular growth, regulating the entry of the cell into the S-phase. P53 mutations have been identified in a progressively increasing number of human malignancies. Nuclear p53 protein is usually present in non-tumour cells in minute concentrations, due to its short half-life. In contrast, tumours with p53 mRNA mutations show a higher nuclear protein concentration, detectable by immunohistological techniques, due to stabilization by complexing with other proteins such as heat-shock protein or wild-type p53 protein. Levels of nuclear p53 protein detected by immunohistochemistry with the monoclonal antibody PAb 1801 were measured with the aid of an image analysis system in 83 non-Hodgkin's lymphomas (NHLs) and 13 cases of Hodgkin's disease, as well as in 14 cases of normal thymus, reactive tonsils, and lymphadenitis. High levels of p53 protein (greater than 5 per cent of the cells) were present only in high-grade lymphomas (in the proportion 13/55), with a peak incidence in Burkitt's lymphoma (5/8 cases). Lower levels (less than 5 per cent) of p53 protein were detected in low-grade B- and T-cell lymphomas, as well as in most of the cases of Hodgkin's disease, where p53 protein was selectively present in Hodgkin and Reed-Sternberg cells. In 5/14 reactive tonsils or lymph nodes, occasional p53-positive cells were identified. These results suggest a relationship between levels of p53 protein and the aggressiveness of NHL.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗

PubMed1992

Malignant lymphoma of jejunum with common variable hypogammaglobulinemia and diffuse nodular hyperplasia of the small intestine. A case study and literature review.

We report a patient with common variable hypogammaglobulinemia and diffuse nodular lymphoid hyperplasia of the small intestine complicated by a jejunal malignant lymphoma. Immunopathological and histological studies showed a polymorphous centroblastic lymphoma with intracytoplasmatic IgM immunoglobulin and lambda light chains. Some mucosal nodules separate from the tumor mass showed atypical lymphoid cell populations similar to lymphoma cells, suggesting a transition between hyperplastic nodules and lymphoma nodules. Four similar cases, and six other patients with malignant lymphoma of the small intestine, associated with diffuse nodular lymphoid hyperplasia, but without immunodeficiency, have already been described. All these cases suggest that nodular lymphoid hyperplasia increases the risk of small intestine lymphoma.

Adult↗

PubMed1991

Effectiveness of histopathological diagnoses in dysfunction of hepatic transplantation. Review of 146 histopathological studies from 53 transplants.

In 47 patients who underwent 53 liver transplantations and immunosuppression with cyclosporine (cyclosporin A), methylprednisolone sodium succinate, and antithymocyte globulin, 146 histopathological studies were performed (138 biopsies, six hepatectomies, and two autopsies). The following microscopical diagnoses were made: 43 acute rejections (29.4%), six chronic rejections (4.1%), 18 liver blood perfusion changes (12.3%), 15 biliary changes (10.2%), 10 cases of functional cholestasis (6.8%), two drug reactions (1.3%), two hepatitis B virus recurrences (1.3%), 11 opportunistic viral infections (7.5%), 18 minimal changes (12.3%), two nonclassifiable changes (1.3%), and 19 plurietiological changes (13%). A histopathological diagnosis of acute rejection was made in 31 transplants (58.4%). In 22 (71%) of them, acute rejection was diagnosed with the protocol biopsy specimen that was obtained during the second posttransplant week. Leukocyte counts and serum bilirubin and enzyme levels were obtained on the same day that the hepatic biopsy specimens were taken. There was no significant statistical difference between the mean serum data that accompanied each histopathological diagnosis, allowing identification of a characteristic biochemical profile for the causes of graft dysfunction. We report a detailed description of the microscopical findings of each diagnosis and the following conclusions: (1) Acute rejection is the most frequent cause of hepatic dysfunction and has an early appearance during the posttransplant period. (2) Histopathological findings can identify the causes of the dysfunction. (3) There is no specific biochemical pattern to differentiate these causes. This may be due to the frequent combination of etiological factors in every dysfunction episode.

Adult↗

PubMed1991

Different bcl-2 protein expression in high-grade B-cell lymphomas derived from lymph node or mucosa-associated lymphoid tissue.

High-grade B-cell lymphomas, whether originated in a lymph node or in mucosa-associated lymphoid tissue (MALT), show similar morphologic traits, a fact that has fueled a long-running controversy about whether they represent different entities. They differ, however, in that some high-grade MALT lymphomas show less aggressive clinical behavior, a focal low-grade component being identified in some of them. In a search for bcl-2 protein expression, we have found a significant difference between nodal (39/48) and MALT high-grade B-cell lymphoma (1/15) (P less than 0.01). Bcl-2 gene product is an inner mitochondrial membrane protein able to give a survival advantage to B-cell lines by blocking programmed cell death. This protein is usually expressed by memory or resting B cells, most activated B cells being bcl-2 negative, except in lymph-node-originated high-grade B-cell lymphomas, which appear to be mainly bcl-2 positive. Presence of bcl-2 protein in nodal large-cell lymphomas seems to be independent of a t(14;18) translocation, only being found in 19 to 28% of these lymphomas, although it constitutes a definite difference between both tumors, suggesting the existence of different molecular genetic characteristics and pathogenesis, and is possibly related to the more aggressive clinical behavior of nodal high-grade tumors.

Cell Transformation, Neoplastic↗

PubMed1990

Cranial fasciitis of childhood with reactive periostitis.

We report a rare case of cranial fasciitis in an 11-year-old girl. The patient was found to have an ossifying soft tissue mass over the occiput that was arising from the cranial periosteum and the deep fascial layer. An associated florid periosteal reaction was found in the occipital bone adjacent to the scalp mass. The computed tomography and histologic pattern of this unusual lesion are discussed. A brief review of the literature is included emphasizing the need to investigate further this completely benign lesion that frequently is confused with a malignant neoplasm.

Child↗

PubMed1990

[The inefficacy of zidovudine (AZT) in progressive multifocal leukoencephalopathy (PML) associated with the acquired immunodeficiency syndrome (AIDS)].

The clinical case of a patient suffering AIDS who presented a progressive multifocal leukoencephalopathy (PML), diagnosed by CT scan, magnetic resonance imaging (MRI) and cerebral biopsy, is here described. A therapeutic trial was carried out with zidovudine (200 mg/4 hours p.o.) during 75 days. Although this treatment diminished the number of infections, a progression of PML was clinically observed, as well as the appearance of new lesions in the cerebral white matter in the MRI. The inefficacy of zidovudine in PML associated to AIDS is discussed.

Acquired Immunodeficiency Syndrome↗