Alessandro Poletti

Surgical Pathology of primary cardiac and pericardial tumors

OBJECTIVE Retrospective study of surgical pathology experience on cardiac and pericardial tumors at the University of Padua in the era of immunohistochemistry and endomyocardial biopsy. METHODS In the period 1970-1995, we studied 125 bioptic primary neoplasms: specimens were obtained from surgical resection in 116 cases, heart transplantation in 3, pericardiectomy in 3, endomyocardial biopsy in 2 and thoracoscopic biopsy in 1. Tumor histotype was established by light microscopy and more recently by immuno-histochemistry, using a large panel of antibodies, through avidin-biotin peroxidase method, against factor VIII-related antigen, ulex-europaeus, desmin, myoglobin, muscle-specific actin, smooth muscle-specific actin, vimentin, cytokeratins, leukocytic common antigen, neurofilaments and S100-protein. RESULTS One hundred and thirteen were benign neoplasms: myxoma was the most frequent (87 cases) followed by pericardial cyst (8), endocardial papilloma (5), fibroma (3), rhabdomyoma (3), hematic cyst (2), teratoma (2), hemangioma (1), celothelioma (1) and lipoma (1). Malignancy was diagnosed in 12 cases, and consisted of pericardial mesothelioma (3), myxosarcoma (3), angiosarcoma (2), fibrosarcoma (2) and leiomyosarcoma (2); 4 of them were intracavitary atrial masses and were supposed to be atrial myxoma on the clinical ground. Differential diagnosis included endocardial thrombosis (10), metastasis of concealed extracardiac tumors (5), echinococcosis (3), and Loefflers fibroplastic endocarditis (3). In 4 cases, cardiac mass histotype was defined without thoracotomy, through endomyocardial (3) and thoracoscopic (1) biopsy. CONCLUSIONS A large spectrum of cardiac tumors is observed in the surgical pathology practice. Although the diagnosis of cardiac masses is easily attainable by routine imaging techniques, differential diagnosis between primary and secondary tumors, malignant and benign forms, and non neoplastic masses, is achievable only by a thorough microscopic study of surgical resections. The role of the cardiac pathologist is becoming crucial as in other fields of oncology.

Sudden death in the young. Is acute coronary thrombosis the major precipitating factor

BACKGROUND Atherosclerotic coronary artery disease, complicated by acute thrombosis, is the usual cause of sudden death in adults. This study addresses the pathology of coronary arteries in sudden death in the young (< or = 35 years old). METHODS AND RESULTS Among 200 consecutive cases of sudden death in youth in the Veneto region of Italy, 37 (33 men and 4 women, age 18 to 35 years; mean, 29.4 years) showed obstructive atherosclerotic coronary artery disease in the absence of other cardiac pathological conditions and causes of death. No patient had previous angina pectoris or myocardial infarction. Cardiac arrest occurred at rest in 30 subjects and was related to effort in 7. A histological study was carried out on the obstructive coronary plaques. Degree of lumen stenosis and extension of lipid core and intimal fibrocellular hyperplasia facing the lumen were calculated morphometrically. Immunohistochemistry and electron microscopy were used to further characterize the plaque cell population. Single-vessel disease was found in 33 patients and triple-vessel disease in 4, with an overall total of 45 obstructive plaques, 34 of which were located in the proximal left anterior descending coronary artery. At histological study, only 10 plaques from 10 patients showed acute thrombosis (occlusive in 5 and subocclusive in 5); the remaining 35 were uncomplicated. Thirty-one plaques were fibrous in nature, while the other 14 were atheromatous. Compared with the atheromatous lesions, the fibrous plaques were rarely complicated by thrombosis (3% versus 64%; P < .001) and distinctly exhibited a fairly well-preserved tunica media (81% versus 21%; P < .001) as well as a stratum of neointimal fibrocellular hyperplasia (68% versus 7%; P < .001), which on immunohistochemistry and electron microscopy appeared to be proliferating smooth muscle cells. CONCLUSIONS In our study population, sudden death was precipitated by acute coronary thrombosis in only 27% of patients with obstructive coronary atherosclerotic plaque. Most of the young victims of sudden death with obstructive coronary atherosclerosis showed single-vessel disease that affected the left anterior descending coronary artery and was due to fibrous plaques with neointimal smooth muscle cell hyperplasia and a preserved tunica media in the absence of acute thrombosis.

High incidence of anti‐FVIII antibodies against non‐coagulant epitopes in haemophilia A patients: a possible role for the half‐life of transfused FVIII

The occurrence of antibodies (Abs) capable of inhibiting factor VIII (FVIII) coagulant activity is a severe complication in haemophilia A, leading to the inhibition of transfused FVIII activity. It is not known whether, or to what extent, post‐transfusion antibodies may also arise against non‐coagulant epitopes. Therefore we set up a system capable, in theory, to detect all the FVIII‐induced antibodies by use of an enzyme‐linked immunoassorbent assay (ELISA) based on coating human recombinant FVIII onto polystyrene microtitre plates. Serum samples from 23 patients affected by haemophilia A of different gravity (22 referred to our Centre and one to the Bari Centre) were analysed. Although only one patient was positive at Bethesda assay, the presence of antibodies in ELISA was detected in 39% of patients in variable degrees; transfusion with FVIII was found to induce a raise in antibody titre, arguing in favour of the specificity of the phenomenon. The clinical relevance of these non‐inhibitory antibodies was evaluated in three patients; although half‐life did not show any change in the patients without or with low amount of antibodies, FVIII clearance was found enhanced in the patient displaying high titre antibodies. We propose detection of anti‐FVIII antibodies by ELISA when routinely assessing haemophilia A patients.

Epstein-Barr virus-associated post-transplant lympho-proliferative disease of donor origin in liver transplant recipients

BACKGROUND/AIMS Post-transplant lymphoproliferative disease, a potential complication of solid organ transplantation, occurs in about 3% of orthotopic liver transplant recipients. We report the genetic and virological characterization of two cases of post-transplant lymphoproliferative disease that occurred early (4 and 6 months) after orthotopic liver transplant as large-cell non-Hodgkins lymphomas located at the hepatic hilum. METHODS Lymphomatous tissues were analyzed for clonality and presence of Epstein-Barr virus (EBV) sequences by Southern blot, polymerase chain reaction, and in situ hybridization techniques. RESULTS The tumors in both cases were sustained by a clonal proliferation of B lymphocytes containing type A EBV DNA. Moreover, in situ hybridization with a digoxigenin-labeled EBV-specific probe evidenced a strong nuclear signal in most of the neoplastic cells. DNA microsatellite analysis at three different loci detected alleles of donor origin in both tumor samples, suggesting that the neoplastic B cells were of donor origin. CONCLUSIONS EBV-infected donor B lymphocytes might be responsible for intragraft post-transplant lymphoproliferative disease in orthotopic liver transplant recipients. As 20 to 30% of post-transplant lymphomas involve the graft itself, donor-derived post-transplant lymphoproliferative disease might be more frequent than presently appreciated. Prospective studies are needed to assess its real incidence and identify possible risk factors.

Heterogeneous immunostaining patterns of follicular dendritic reticulum cells in human lymphoid tissue with selected antibodies reactive with different cell lineages.

A comparative immunohistologic study of the cell density and distribution pattern of follicular dendritic reticulum cells (DRCs) within their follicular microenvironments (germinal centers and mantle zones) was performed by immunoperoxidase technique with a selected panel of antibodies either operationally specific for DRCs (DRC-1) or reported as having additional immunoreactivity with DRCs (antibodies to B- and T-cells, leukocytes, monocytes/macrophages, desmosomal components, and S-100 protein). Twenty-five biopsy specimens, including reactive lymph nodes and tonsils as well as normal spleen tissue, were analyzed. Serial frozen sections were tested either with single antibodies or paired monoclonal reagents in double-labeling procedures. Our results consistently indicated that DRCs positive for Leu M3 and BA-2 antibodies were confined to the central portion of germinal centers, whereas DRCs immunoreactive for S-100 protein and desmoplakin 1 and 2 were localized mostly in the central and pericentral portion of germinal centers. All the DRCs extending from the central portion of germinal centers to the mantle zones were labeled with DRC-1 and, unexpectedly, with OKB7 antibodies. Other immunostainings, such as those for HLA-DR antigens, common leukocyte antigen, and Leu 3a, were not contributory in defining topographic differences of DRCs within the follicle. The consistent heterogeneity of the labeling patterns appears to suggest a possible in situ immunophenotypic grouping of DRCs, and the concept of their possible heterogeneity appears to be corroborated.

Detection of B-Cell Monoclonality in Fine Needle Aspiration by PCR Analysis

Cytologic examination of fine-needle aspiration (FNA) sometimes fails to diagnose the malignant nature of B-cell proliferations. In this study we analyzed the Ig gene rearrangement of 49 FNA samples by polymerase chain reaction (PCR) in order to evaluate whether molecular analyses can improve the accuracy of FNA. Twenty-six patients had non-Hodgkins lymphoma, 11 had reactive lymphoid diseases, 5 had chronic inflammation and 7 had carcinoma. A semi-nested PCR was performed using an oligoprimer specific for consensus sequences of the V regions (FR3A) and two oligoprimers derived from conserved sequences of the J regions (LJH and VLJH). Histologic examination always followed the molecular and cytologic analysis. The sensitivity of PCR and FNA morphological examination in detecting a neoplastic pattern was 92% and 78%, respectively. When samples were considered inadequate for cytologic examination, PCR always reached a diagnosis consistent with the histologic features. Our results demonstrate that PCR analysis of FNA specimens is a reliable and sensitive method capable of enhancing the diagnostic accuracy of cytologic examination.

Heterogeneous in situ immunophenotyping of follicular dendritic reticulum cells in malignant lymphomas of B-cell origin

The phenotype of follicular dendritic reticulum cells (DRC) was analyzed with monoclonal antibodies (DRC‐1, OKB7, BA‐2, Leu‐M3, and antidesmoplakin 1 and 2) in 28 frozen biopsy specimens of both morphologically and phenotypically analyzed B‐cell lymphomas and 21 normal or reactive controls. The former included 15 follicular center cell lymphomas (FCCL), four intermediately differentiated lymphocytic lymphomas (ILL), four mantle zone lymphomas (MZL), and five well‐differentiated lymphocytic lymphomas (WDLL). In controls, DRC‐1+ and OKB7+ DRC were localized in both follicular centers (FC) and mantle zones (MZ), but BA‐2+ and Leu‐M3+ DRC were confined to FC only. FCCL were usually accompanied by DRC‐1+, OKB7+, and BA‐2+ DRC, and either lost or maintained positivity with Leu‐M3 from case to case. By contrast, MZL consistently lacked BA‐2+ and Leu‐M3+ DRC, and was associated with DRC‐1+ and OKB7+ DRC only. Desmoplakin‐positive DRC occurred in variable proportions in both FCCL and MZL. As opposed to FCCL and MZL, all WDLL and all but one of the ILL (associated only with DRC‐1+, OKB7+, and desmoplakin+ DRC) did not show any DRC as identifiable with the antibody panel used. Remarkably, the difference in the distribution of BA‐2+ and Leu‐M3+ DRC in the normal FC and MZ appears to be maintained in their neoplastic counterparts (FCCL and MZL) also. Such a difference represents an example of the possible interactions between lymphoma cells of different phenotype and their microenvironment, as portrayed by phenotypically heterogeneous DRC.

Uncommon metastatic site of renal adenocarcinoma: The oral tongue

Primary tumours metastasizing to the tongue are very unusual and only anecdotal cases have been reported. An exhaustive literature review covering the period from 1970 onwards disclosed only 22 cases of renal adenocarcinoma metastasizing to the tongue. We report the case of an 87-year-old female patient with oral tongue, lung, liver, thyroid gland, pancreas and renal adenocarcinoma metastases. She had undergone contralateral nephrectomy for clear cell carcinoma 10 years before diagnosis of the metastases. The tongue lesion was surgically removed under local anaesthesia. Tongue metastasis of renal adenocarcinoma is usually a manifestation of widespread disease. The prognosis for patients with lingual metastasis of renal adenocarcinoma is poor, the mean interval from diagnosis of tongue metastasis to death being 5.8 months. In our patient, metastatic involvement of the tongue was detected ≈5 months before death. Treatment of renal adenocarcinoma metastasis to the tongue is usually palliative and aims to provide patient comfort by means of pain relief and prevention of bleeding and infection. Surgical excision is recommended as the primary treatment, with emphasis on preservation of tongue structure and function. Recent data regarding immunotherapy or immunochemotherapy for metastatic renal adenocarcinoma are encouraging.

MALT-type lymphoma and Warthin's tumour presenting in the same parotid gland

Non-disseminated malignant lymphomas of salivary glands occurring in association with Warthins tumour have rarely been reported. We describe the first case of association of an extranodal mucosa-associated lymphoid tissue (MALT)-type non-Hodgkins lymphoma with Warthins tumour of the parotid gland. Total parotidectomy with preservation of the facial nerve was performed. Surgical and pathological evidence confirmed that the parotid MALT lymphoma did not arise in the lymphoid stroma of the Warthins tumour. Immunostaining of the MALT lymphoma cells proved negative for Epstein–Barr virus and Helicobacter pylori antibodies and polymerase chain reaction assays did not identify human herpesvirus 8. The patient has been followed up for 11 months, without evidence of recurrent disease. It cannot be ruled out that long-term immunological stimulation by the Warthins tumour may have caused lymphoid accumulation, chronic stimulation of B cells and extranodal parotid MALT lymphomagenesis.

Intermediate lymphocytic lymphoma encompassing diffuse and mantle zone pattern variants: A distinct entity among low-grade lymphomas?☆

Intermediate lymphocytic lymphoma has been operationally included among low-grade lymphomas, but few clinical data appeared to support definitely such an inclusion. The clinicopathologic features of 13 out of 14 cases of intermediate lymphocytic lymphoma either encompassing diffuse or mantle-zone pattern variants (ILL or MZL, respectively), diagnosed by conventional histology according to established criteria, are reported. Frozen section immunophenotypic analysis was also performed in 10 cases and enzyme studies were done in five. The 14 cases formed 6.9% of 203 non-Hodgkins lymphomas (NHL) histologically diagnosed over a 2-year period. Among the 13 cases studied, there were nine males (five with ILL and four with MZL) and four females (one with ILL and three with MZL). Median age was 59 years. Splenomegaly (46%), high stage diseases (100%), involvement of bone marrow (92%) and peripheral blood (38%), and diffusion to and/or involvement of extranodal sites (38%), all were common findings at presentation. The 34 low-grade NHL of the total series classified according to the Working Formulation did not significantly differ from the ILL/MZL group in terms of frequency of involvement of bone marrow (69%) and peripheral blood (56%) as well as diffusion to and/or involvement of extranodal sites (26%). In ILL/MZL, therapy modalities were not uniform and the short follow-up time precluded firm conclusions on prognosis. Immunohistology demonstrated that ILL/MZL diagnosed by adequate morphologic criteria is a fairly homogeneous entity, also sharing most of its consistent immunological features with low-grade NHL. Thus, ILL/MZL is a relatively frequent and consistently recognizable clinical and pathological entity that may deserve a distinct place among NHL according to the Working Formulation. Proper clinical studies are needed to establish on a firmer basis the prognosis and optimal treatment of ILL/MZL.