Myeloid/lymphoid neoplasms with eosinophilia and tyrosine kinase fusion genes: A workshop report with focus on novel entities and a literature review including paediatric cases.

Myeloid/lymphoid neoplasms with eosinophilia (M/LN-eo) and tyrosine kinase (TK) gene fusions are a rare group of haematopoietic neoplasms with a broad range of clinical and morphological presentations. Paediatric cases have increasingly been recognised. Importantly, not all appear as a chronic myeloid neoplasm and eosinophilia is not always present. In addition, standard cytogenetic and molecular methods may not be sufficient to diagnose M/LN-eo due to cytogenetically cryptic aberrations. Therefore, additional evaluation with fluorescence in-situ hybridisation and other molecular genetic techniques (array-based comparative genomic hybridisation, RNA sequencing) are recommended for the identification of specific TK gene fusions. M/LN-eo with JAK2 and FLT3-rearrangements and ETV6::ABL1 fusion were recently added as a formal member to this category in the International Consensus Classification (ICC) and the 5th edition of the WHO classification (WHO-HAEM5). In addition, other less common defined genetic alterations involving TK genes have been described. This study is an update on M/LN-eo with TK gene fusions with focus on novel entities, as illustrated by cases submitted to the Bone Marrow Workshop, organised by the European Bone Marrow Working Group (EBMWG) within the frame of the 21st European Association for Haematopathology congress (EAHP-SH) in Florence 2022. A literature review was performed including paediatric cases of M/LN-eo with TK gene fusions.

Progression, transformation, and unusual manifestations of myelodysplastic syndromes and myelodysplastic-myeloproliferative neoplasms: lessons learned from the XIV European Bone Marrow Working Group Course 2019.

Disease progression in myelodysplastic syndromes (MDS) and myelodysplastic-myeloproliferative neoplasms (MDS/MPN) is a major source of mortality. The European Bone Marrow Working Group organized a dedicated workshop to address MDS and MDS/MPN progression, and myeloid neoplasms with histiocytic and lymphoblastic outgrowths in 2019 in Frankfurt, Germany. In this report, we summarize clinical, histopathological, and molecular features of 28 cases. Most cases illustrate that prognostic mutational profiles change during follow-up due to accumulation of high-risk mutations in the trunk clone, and that results from repeated molecular testing can often explain the clinical progression, suggesting that regular genetic testing may predict transformation by early detection of aggressive clones. Importantly, identical mutations can be linked to different clinical behaviors or risks of fibrotic progression and/or transformation in a context-dependent manner, i.e., MDS or MDS/MPN. Moreover, the order of mutational acquisition and the involved cell lineages matter. Several cases exemplify that histiocytic outgrowths in myeloid neoplasms are usually accompanied by a more aggressive clinical course and may be considered harbinger of disease progression. Exceptionally, lymphoblastic transformations can be seen. As best estimable, the histiocytic and lymphoblastic compounds in all occasions were clonally related to the myeloid compound and-where studied-displayed genomic alterations of, e.g., transcription factor genes or genes involved in MAPK signaling that might be mechanistically linked to the respective type of non-myeloid outgrowth.

Mummified Cells are a Common Finding in Cutaneous Hodgkin Lymphoma and Can Be Used as a Diagnostic Clue.

Specific cutaneous involvement in Hodgkin lymphoma is rare. In cutaneous lesions, the diagnosis is usually based on the recognition of diagnostic Reed-Sternberg cells and its variants. In nodal Hodgkin lymphoma, so-called mummified cells (cells with condensed cytoplasm and pyknotic eosinophilic or basophilic nuclei) are often seen. They are sometimes conspicuous and easy to recognize, thus serving as a clue to the diagnosis. Our objective was to study cases of cutaneous Hodgkin lymphoma to identify the occurrence of mummified cells. We studied 12 patients (4 women and 8 men; age range 23-80 years). In 6 patients, cutaneous and extracutaneous disease was identified almost simultaneously; in 4 patients, lymph node disease preceded cutaneous involvement; and in the remaining 2 patients, the skin lesions were the presenting sign, whereas lymph node involvement occurred later. Histopathological, immunohistochemical, and molecular-genetic studies, including rearrangements for TCR, IgH genes, and PCR for EBV, were performed. Cutaneous biopsy specimens revealed either a multinodular or diffuse infiltrate, included small lymphocytes, eosinophils, plasma cells, and macrophages, but in all cases, diagnostic Reed-Sternberg cells and its variants were identified. Mummified cells were detected in 9 cases, either as occasional scattered mummified cells often requiring a search (6 cases) or being conspicuous, grouped and therefore easily identified (3 cases). Immunohistochemically, in all 7 cases studied, mummified cells were positive for both CD30 and CD15. It is concluded that mummified cells are encountered in a majority of cases of cutaneous Hodgkin lymphoma.

Challenges in Diagnosing Myelodysplastic Syndromes in the Era of Genetic Testing: Proceedings of the 13th Workshop of the European Bone Marrow Working Group.

The 13th workshop of the European Bone Marrow Working Group in Utrecht, The Netherlands, was devoted to studying myelodysplastic syndromes (MDS) and their boundaries. The panel received 44 cases submitted to the 3 invited categories, which included: reactive cytopenias with dysplasia, idiopathic cytopenia of undetermined significance, clonal haematopoiesis of indeterminate potential, idiopathic dysplasia of uncertain significance and overt MDS. For this summary, we have selected 17 cases that highlight difficulties in separating true MDS from other causes of cytopenia and the intricate relationship between clonal haematopoiesis and true MDS. In addition, cases of overt MDS with challenging features were also selected. All cases were stained for p53 expression. Using instructive submitted cases we discuss the following: (1) cytopenia with clonal haematopoiesis not fulfilling MDS criteria, (2) cytopenia and/or dysplasia with germline mutations and/or familial history suggesting an underlying gene defect, (3) MDS based on a recurrent chromosomal abnormality and (4) overt MDS with diagnostic difficulties due to concurrent treatment or disease. The lively discussion in the open forum of the workshop illustrated the need for better integrative understanding of the evolution of acquired genetic abnormalities in haematopoiesis, and the challenge of diagnosing true MDS in cytopenic patients with genetic abnormalities, either germline or acquired.

[Microvascular density in lymphomas - evaluation methods and clinical impact]. / Mikrovaskulární denzita v lymfomech - hodnocení a klinický význam.

In recent years antiangiogenic therapy has become a part of treatment protocols of solid tumors as well as of lymphomas. This is why tumor vascularization has been explored, the most important parameters to describe it being the microvascular density and immunohistochemical assessment of the expression of VEGF (vascular endothelial growth factor) and of its receptors. This review summarizes various methods of assessment of the microvascular density and the prognostic impact of microvascular density in lymphomas.

Microvessel density of mantle cell lymphoma. A retrospective study of its prognostic role and the correlation with the Ki-67 and the mantle cell lymphoma international prognostic index in 177 cases.

The clinical course and therapy of mantle cell lymphoma (MCL) are heterogeneous and often unsatisfactory. Prognostic factors are needed to stratify the patients. Microvessel density (MVD) has prognostic significance in some malignancies. There is little information about the vasculature of MCL, although some antiangiogenic drugs are in use. We studied MVD using systematic uniform random sampling and unbiased counting frames in immunohistochemical reactions with anti-CD34 antibody in pre-therapeutic extramedullary MCL samples of 177 patients. We analyzed the relationship of MVD to overall survival (OS) and progression-free survival (PFS), as well as to proliferative activity (Ki-67), mantle cell lymphoma prognostic index (MIPI), morphological variant, pattern of growth, and localization. MVD varied widely: range 54.6-503.6 vessels/mm(2), median 158.2 vessels/mm(2). Higher MVD was associated with bone marrow infiltration at the time of diagnosis (P = 0.001). High MVD was associated with significantly worse OS (P = 0.04) only in patients treated with non-intensive (conventional) therapy. MVD correlated positively with MIPI scores but not with the proliferation, morphological variant, growth pattern, or localization. Univariate analysis identified a prognostic influence of morphological variant, MIPI, and proliferative activity on OS and PFS and a prognostic influence of bone marrow infiltration at the time of diagnosis on PFS. Multivariate analysis showed prognostic influence of MIPI and proliferative activity on OS and PFS only. In conclusion, this is the first clinicopathological study of MVD of MCL with long-term follow-up showing negative prognostic trends of high MVD in MCL and positive correlation of MVD and MIPI.

Prevalence of Achromobacter xylosoxidans in pulmonary mucosa-associated lymphoid tissue lymphoma in different regions of Europe.

Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) comprises 7-8% of B-cell lymphomas and commonly originates from a background of long-standing chronic inflammation. An association with distinct bacteria species has been confirmed for several anatomical sites of MALT lymphoma. For pulmonary MALT lymphoma, however, a clear link with an infectious agent or autoimmune disorder has not yet been reported. Using a 16S rRNA gene-based approach, we have recently identified Achromobacter (Alcaligenes) xylosoxidans in eight of nine cases of pulmonary MALT lymphoma. A. xylosoxidans is a gram-negative betaproteobacterium with low virulence, but high resistance to antibiotic treatment. To further examine a potential association with A. xylosoxidans, 124 cases of pulmonary MALT lymphoma and 82 control tissues from six European countries were analysed using a specific nested PCR. Although prevalence rates for A. xylosoxidans varied significantly from country to country, they were consistently higher for MALT lymphoma as compared to controls. Overall, 57/124 (46%) pulmonary MALT lymphomas and 15/82 (18%) control tissues were positive for A. xylosoxidans (P = 0·004). Whether the significant association of A. xylosoxidans with pulmonary MALT lymphoma demonstrated in our study points to a potential causal role in the pathogenesis of this lymphoma will require further studies.

Langerhans cell histiocytosis in childhood - review, symptoms in the oral cavity, differential diagnosis and report of two cases.

BACKGROUND: Langerhans cell histiocytosis is a rare disease characterized by monoclonal proliferation and migration of special dendritic cells. This disease primarily affects bones, but occurs less frequently in other organ systems or may manifest as a multisystem disease. CASE REPORTS: Extraoral and intraoral symptoms of Langerhans cell histiocytosis are described in a 13-month-old female and a 5-month-old male infant. Dermatitis was found on the scalp, abdomen, flexures and in intertrigineous areas in both patients. The intraoral examination of the 13-month-old infant showed premature eruption of all maxillary deciduous molars, loosening and significant damage of periodontal tissues (gingivitis with bleeding, swelling of palatal mucosa, periodontal pockets) resembling severe periodontitis. In the oral cavity of the 5-month-old predentate infant bilateral swellings of maxillary alveolar mucosa with deep ulcerations were seen. The oral and skin symptoms in both infants were indications for biopsy. Langerhans cell histiocytosis was confirmed histologically and immunohistochemically. CONCLUSION: Oral findings in Langerhans cell histiocytosis may be the only clinical symptom of the disease; therefore the role of dentists in establishing diagnosis is very important.

Retrospective analysis of 235 unselected patients with mantle cell lymphoma confirms prognostic relevance of Mantle Cell Lymphoma International Prognostic Index and Ki-67 in the era of rituximab: long-term data from the Czech Lymphoma Project Database.

Although a prognostic model (MIPI, Mantle Cell Lymphoma International Prognostic Index) for patients with mantle cell lymphoma (MCL) has been established, its clinical significance for daily practice in the rituximab era remains controversial. Data of 235 unselected patients with MCL from the Czech Lymphoma Project Database were analyzed. MIPI, simplified MIPI (s-MIPI) and Ki-67 proliferation index were assessed for all patients and for a subgroup of 155 rituximab-treated (RT) patients. MIPI divided all patients into subgroups of low-risk (22%), intermediate-risk (29%) and high-risk (49%), with median overall survival 105.8 vs. 54.1 vs. 24.6 months, respectively (p < 0.001). s-MIPI revealed similar results. The validity of both indexes was confirmed in RT patients. We confirmed the Ki-67 index to be a powerful single prognostic factor for overall survival (64.4 vs. 20.1 months, p < 0.001) for all patients and for the RT subset. Our results confirm the clinical relevance of MIPI, s-MIPI and Ki-67 for risk stratification in MCL also in the rituximab era.

P27 as a prognostic factor of early cervical carcinoma.

OBJECTIVE: The aim of this study was to clarify whether the evaluation of cell-cycle regulatory protein p27 can serve as a prognostic factor in patients with International Federation of Gynecology and Obstetrics (FIGO) stage IB cervical carcinoma. PATIENTS AND METHODS: A retrospective study was performed on 130 surgically treated patients with FIGO stage IB cervical carcinoma with at least a 5-year follow-up. The expression of p27 was investigated independently by 2 experienced pathologists using immunohistochemistry. The prognostic significance of established prognostic factors and p27 expression were analyzed using univariate and multivariate analyses. RESULTS: In a univariate analysis, lymph node status, tumor diameter, Gynecologic Oncology Group (GOG) score, lymph vascular space invasion, and p27 expression were significant prognostic factors for overall survival (OS). We found a correlation between p27 expression and lymph node status, tumor diameter, invasion, and GOG score. The p27 expression was a statistically significant prognostic factor for OS in a univariate analysis (log-rank test, P = 0.03). In a multivariate analysis, only lymph node status and tumor diameter were statistically significant prognostic factors for OS. CONCLUSIONS: This study demonstrated that a low p27 expression is associated with lymph node metastasis, deep stromal invasion, tumor diameter more than 20 mm, and high GOG score and had a prognostic influence on OS in a univariate analysis in a series of 130 women with FIGO stage IB cervical carcinoma. Lymph node status and the diameter of the tumor were the only statistically significant prognostic factors in multivariate analysis.

The germinal center/activated B-cell subclassification has a prognostic impact for response to salvage therapy in relapsed/refractory diffuse large B-cell lymphoma: a bio-CORAL study.

PURPOSE: To evaluate the prognostic value of the cell of origin (COO) in patients with relapsed/refractory diffuse large B-cell lymphoma (DLBLC), prospectively treated by rituximab, dexamethasone, high-dose cytarabine, and cisplatin (R-DHAP) versus rituximab, ifosfamide, carboplatin, and etoposide and followed by intensive therapy plus autologous stem-cell transplantation on the Collaborative Trial in Relapsed Aggressive Lymphoma (CORAL) trial. PATIENTS AND METHODS: Among the 396 patients included on the trial, histologic material was available for a total of 249 patients at diagnosis (n = 189 patients) and/or at relapse (n = 147 patients), which included 87 matched pairs. The patient data were analyzed by immunochemistry for CD10, BCL6, MUM1, FOXP1, and BCL2 expression and by fluorescent in situ hybridization for BCL2, BCL6 and c-MYC breakpoints. The correlation with survival data was performed by using the log-rank test and the Cox model. RESULTS: Characteristics of immunophenotype and chromosomal abnormalities were statistically highly concordant in the matched biopsies. In univariate analysis, the presence of c-MYC gene rearrangement was the only parameter to be significantly correlated with a worse progression-free survival (PFS; P = .02) and a worse overall survival (P = .04). When treatment interaction was tested, the germinal center B (GCB) -like DLBCL that was based on the algorithm by Hans was significantly associated with a better PFS in the R-DHAP arm. In multivariate analysis, independent prognostic relevance was found for the GCB/non-GCB the Hans phenotype interaction treatment (P = .04), prior rituximab exposure (P = .0052), secondary age-adjusted International Prognostic Index (P = .039), and FoxP1 expression (P = .047). Confirmation was obtained by gene expression profiling in a subset of 39 patients. CONCLUSION: COO remains a major and independent factor in relapsed/refractory DLBCL, with a better response to R-DHAP in GCB-like DLBCL. This needs confirmation by a prospective study.

Significant oral graft-versus-host disease after allogeneic stem cell transplantation with the FLU/MEL conditioning regimen.

BACKGROUND: Oral graft-versus-host disease (GVHD) is a significant complication after allogeneic stem cell transplantation (SCT) and there is no consistent information about its characteristics in patients after reduced-intensity conditioning regimen FLU/MEL (fludarabine 120 mg/m² and melphalan 140 mg/m²). MATERIAL/METHODS: This was a single-centre prospective observational study of patients after allogeneic SCT with FLU/MEL conditioning performed during the period 1/2005-12/2007. Characteristics of oral GVHD were observed in 71 patients. The observation was discontinued due to death, donor lymphocyte infusion (DLI) or new chemotherapy administration. RESULTS: In 10/2010, the median duration of the observation of the cohort of the patients was 13 (0.2-69) months, and 42 (35-69) months in the still-ongoing 20/71 (28%) patients. Oral acute GVHD had sporadic 7% incidence, whereas oral chronic GVHD was observed in 33% of patients and persisted with median duration of 188 (11-665) days. Clinical and histopathological features were similar in both acute and chronic oral GVHD and included mucosal lichenoid changes, erythema, ulcerations and pseudomembranes, satellite necrosis, apoptotic bodies and lichenoid interface inflammation. CONCLUSIONS: It is necessary to consider complex clinical symptomatology and pathological correlations when classifying the oral GVHD, because local oral symptoms and histopathological features in both acute and chronic oral GVHD forms can be similar. Even though the oral chronic GVHD was mild in the majority of patients, it can be considered as clinically significant due to its incidence, duration and symptomatology. The FLU/MEL conditioning regimen should not be considered as low-risk protocol in this context.

Significance of nuclear hTra2-beta1 expression in cervical cancer.

OBJECTIVE: Human Tra2-beta1, a member of the serine/arginine-rich splicing factors, is involved in C/A-dependent mRNA processing and regulation of gene expression. Since several genes involved in cervical carcinogenesis are alternatively spliced and contain C/A rich elements, we aimed to analyze hTra2-beta1 expression and subcellular localization in tumor tissue of women with cervical cancer and to determine its clinical significance. DESIGN: Retrospective study. SETTING: Tertiary-care academic medical center. SAMPLE: One hundred and five patients with cervical cancer and a mean follow up time of 73.1 months. METHODS: Immunohistochemistry of paraffin-embedded tissues was performed and hTra2-beta1 expression was correlated with clinico-pathological variables including patient outcome. RESULTS: Cytoplasmic hTra2-beta1 protein expression was found in 20% of cases, while all tumors revealed nuclear immunoreactivity with strong expression in 54.3% of cases. There was a significant inverse correlation between nuclear and cytoplasmic protein expression, suggesting a potentially relevant shuttle process of hTra2-beta1 between both cellular compartments. Patients with weak expressing hTra2-beta1 tumors showed an improved survival with a tumor-related death rate of 8.3% compared to 23.7% in patients with moderate and high intranuclear hTra2-beta1 expression, respectively. CONCLUSIONS: Our data support the hypothesis of a biological relevance for hTra2-beta1 expression in cervical cancer. The observed shuttle process of this splicing factor with higher concentrations in the nucleus should have pronounced effects on the cellular function and tumor biology of the affected tumors, leading to the worse patient outcome.

Primary cutaneous lymphoproliferative disorders with dual lineage rearrangement.

We present a series of 15 cases of cutaneous lymphoma and pseudolymphoma with dual lineage rearrangement identified among approximately 1200 cases of cutaneous lymphoproliferative disorders assessed in our 4 institutions during the last 8 years in which the results of both T-cell receptor and immunoglobulin heavy chain rearrangement investigations were available. On the basis of the clinicopathologic information, the cases were retrospectively subdivided into 2 categories: (1) cases with definite features of cutaneous lymphoma or pseudolymphoma (n = 11) and (2) cases with unclassifiable disease (n = 4). The detection of dual genotype in the first group did not influence the final diagnosis; 7 cases represented cutaneous B-cell lymphomas, 3 pseudolymphomas, and 1 case lymphomatoid papulosis. The presence of monoclonal T-cell receptor-gene rearrangements in these cases may be explained either by monoclonal or oligoclonal expansion of exuberant T cells (or B cells in case of lymphomatoid papulosis) or by lineage infidelity. Three patients with unclassifiable disease had several clinical and histopathologic features in common. They were elderly, presented with solitary lesions, were in good general health and histopathologically demonstrated a dense multinodular infiltrate containing approximately an equal number of T and B cells and a high number of histiocytes forming granulomas, with prominent granulomatous features in 2 cases. B cells were either scattered with the infiltrate or formed collections vaguely resembling follicles; Reed-Sternberg-like cells were seen in 2 cases. B cells showed expression neither of immunoglobulin light chain. The T-cell component was represented mainly by small, well-differentiated lymphocytes or slightly pleomorphic cells, with some medium-sized convoluted cells. Epstein-Barr virus was not detected by polymerase chain reaction. The exact classification of these cases is unknown; they differ histopathologically from previously published cases of bigenotypic cutaneous lymphomas. They may merely represent a growth or reactive pattern, but, on the other hand, may be low-grade lymphomas. If so, they may be histopathologically related to cutaneous Hodgkin disease, T-cell/histiocyte-rich large B-cell lymphoma, or composite lymphomas. Further reports are needed to identify these lesions to clarify their nature and biologic potential.

Primary cutaneous histiocyte and neutrophil-rich CD30+ and CD56+ anaplastic large-cell lymphoma with prominent angioinvasion and nerve involvement in the forehead and scalp of an immunocompetent woman.

BACKGROUND: Cutaneous lymphomas co-expressing CD56 and CD30 are very rare. They share a clinicopathological overlap with natural killer- (NK)/T-cell lymphomas and anaplastic large-cell lymphomas (ALCLs), two entities with widely disparate clinical behavior. METHODS: We present a case of an immunocompetent 57-year-old Caucasian woman with a rapidly growing, angiodestructive and neuroinvasive primary cutaneous ALCL (PCALCL). The neoplastic population of large anaplastic CD30+ and CD56+ T cells was masked by a massive admixture of histiocytes and neutrophils. The partially ulcerated and pus-secreting tumor involved the forehead and scalp and was assessed as clinical stage IAE. RESULTS: After chemotherapy (cyclophosphamide, doxorubicin, vincristine, and prednisone), the patient achieved a complete remission. Additionally, high-dose chemotherapy with autologous peripheral blood stem-cell transplantation was administered as a consolidation of complete remission, in which she has remained for 6 years. CONCLUSIONS: This is the first CD30+ and CD56+ primary skin lymphoma to be reported on the head. The presented case carries a remarkable combination of clinicopathological features of PCALCL and NK-/T-cell lymphoma.

Subcutaneous splenosis of the abdominal wall.

We report a case of subcutaneous splenosis in the abdominal wall of a 23-year-old oligophrenic man. It presented as a well-demarcated 8 x 7 x 5-cm subcutaneous tumor in the left inguinal area closely above the scar after a previous operation for hernia. The lesion simulated clinically a hernia or a tumor due to its large size and location and, additionally, no history could be taken from the patient due to his mental handicap.

Oncocytic papillary renal cell carcinoma: a clinicopathologic, immunohistochemical, ultrastructural, and interphase cytogenetic study of 12 cases.

Papillary renal cell carcinoma (RCC) is subclassified in type 1 displaying cells with scanty pale cytoplasm arranged in a single layer and in type 2 showing pseudostratified cells with eosinophilic cytoplasm. However, the existence of more variants of papillary RCC may be inferred by the recognition of few cases with different morphological features. We report the clinicopathologic, immunohistochemical, ultrastructural, and interphase cytogenetic features of 12 papillary RCC composed by oncocytes. Ten patients were males and their median age was 67 years. The tumors were well demarcated and their median diameter was 7.1 cm. Solid oncocytoma-like areas occurred in 11 cases. The cytoplasm of the neoplastic cells was filled by mitochondria with lamellar cristae. All cases were positive for the antimitochondrial antigen and racemase and showed variable immunoreactivity for cytokeratins (AE1/AE3, CK8-18, CK7, CK19), EMA, CD10, vimentin, and parvalbumin. MIB1 was detected in 0 to 6 cells per 1 high-power field. Fluorescent in situ hybridization analysis on formalin-fixed paraffin-embedded tissue showed three or more signals for chromosome 7 and 17 (for both > or =30% of nuclei in 7 of 12 neoplasms). In males, signals of chromosome Y were absent in more than 80% of the neoplastic nuclei. One patient died of metastases. Interphase cytogenetic analysis by fluorescent in situ hybridization can be a diagnostic tool in cases mimicking an oncocytoma.

Extensively cystic renal neoplasms in adults (Bosniak classification II or III)--possible "common" histological diagnoses: multilocular cystic renal cell carcinoma, cystic nephroma, and mixed epithelial and stromal tumor of the kidney.

OBJECTIVE(S): To give an algorithm for resolution of extensively cystic renal neoplasms, preoperatively classified in the Bosniak classification as a category II and III. METHODS: From 1991 to 6/2004, 701 patients with 727 renal tumours were surgically treated at our hospital. Extensively cystic tumours were found in 10 cases. Extensively cystic tumours were defined as multicystic tumours without any solid nodules visible neither on CT, nor grossly in the specimen at operation (the Bosniak classification type II or III). RESULTS: Seven multilocular cystic renal cell carcinomas, three mixed epithelial and stromal tumour of the kidney and one cystic nephroma were diagnosed on histology. CONCLUSION(S): Extensively cystic renal tumours classified as the Bosniak type II or III correspond histologically to the entities mentioned above (multilocular cystic renal cell carcinoma, cystic nephroma, mixed epithelial and stromal tumour of the kidney). These entities cannot be distinguished one from another on preoperative imaging studies. A preoperative biopsy and intra-operative frozen-section analysis do not lead to a correct diagnosis in many cases. Fortunately, the operative strategy is the same for all these tumours. In such cases, the nephron sparing surgery is indicated, whenever technically feasible, as almost all extensively cystic renal tumours have a good prognosis.

Cutaneous lymphoid hyperplasia and other lymphoid infiltrates of the breast nipple: a retrospective clinicopathologic study of fifty-six patients.

This study characterizes the clinicopathological spectrum of lymphoproliferations involving the breast nipple and/or areola. Morphologic, immunohistochemical, molecular-genetic, and clinical features of 58 specimens from 56 patients were analyzed. They were re-diagnosed as cutaneous lymphoid hyperplasia (CLH, n = 44); other benign lymphoid infiltrates (OBLI, n = 8); peripheral T-cell lymphoma, not otherwise specified (n = 1); cases with overlapping features of CLH and B-cell lymphoma (n = 3), one of them composed of spindle cells. Cutaneous lymphoid hyperplasia infiltrates were dense, composed mainly of B cells forming follicles with germinal centers (GC). Cutaneous lymphoid hyperplasia frequently showed features suggesting a malignancy as coalescing follicles with non-polarized germinal centers lacking mantle zones, and smudged infiltrates of lymphoid cells spreading into collagen (often as "Indian files"), smooth muscle, vessel walls, and nerve sheaths. Only two cutaneous lymphoid hyperplasias recurred; otherwise all patients are without disease (mean follow-up 62 months). Monoclonal rearrangement of immunoglobulin heavy chain gene was detected in five, and of T-cell receptor gamma gene in two cutaneous lymphoid hyperplasias using polymerase chain reaction (PCR), but the patients fared well too. In 47% of cases Borrelia burgdorferi was detected by polymerase chain reaction and/or serology, of which one was monoclonal. We conclude that cutaneous lymphoid hyperplasia is the most common lymphoproliferation of the breast nipple, rarely recognized clinically, and often overdiagnosed histologically as lymphoma.