Interval sentinel lymph nodes: an unusual localization in patients with cutaneous melanoma.

Background. Recent studies have demonstrated that there exists a great variation in the lymphatic drainage in patients with malignant melanoma. Some patients have drainage to lymph nodes outside of conventional nodal basins. The lymph nodes that exist between a primary melanoma and its regional nodal basin are defined "interval nodes". Interval node occurs in a small minority of patients with forearm melanoma. We report our experience of the Melanoma Unit of University Hospital Spedali Civili Brescia, Italy. Methods. Lymphatic mapping using cutaneous lymphoscintigraphy (LS) has become a standard preoperative diagnostic procedure to locate the sentinel lymph nodes (SLNs) in cutaneous melanoma. We used LS to identify sentinel lymph nodes biopsy (SLNB) in 480 patients. Results. From over 2100 patients affected by cutaneous melanoma, we identified 2 interval nodes in 480 patients with SLNB . The melanomas were both located in the left forearm. The interval nodes were also both located in the left arm. Conclusion. The combination of preoperative LS and intraoperative hand-held gamma detecting probe plays a remarkable role in identifying these uncommon lymph node locations. Knowledge of the unusual drainage patterns will help to ensure the accuracy and the completeness of sentinel nodes identification.

Merkel cell carcinoma and HIV infection: a case report and review of the literature.

Merkel cell carcinoma (MCC) is a skin cancer of neuroendocrine origin that occurs most often in sun-exposed areas. In the general population, it is a disease of older adults, with only 5% of cases occurring below the age of 50 years. Immunosuppression is the significant risk factor for the development of MCC and recently it was suggested that individuals with HIV have a relative risk of 13.4 to developed MCC in comparison with the general population. We report a case of MCC in an HIV-infected patient and we review nine patients with HIV with MCC. Our patient was a 54-year-old man who came to our attention without a known HIV diagnosis. He was apparently in good health and had no risk factor for HIV, but by the atypical site of the lesion and by the relative young age of the patient we suspected a case of immunosuppression and for this reason we did HIV test that had a positive result. The patient was treated with surgery and chemotherapy but died as a result of liver metastases 25 months after his tumor was diagnosed.

[LAT (linker for activation of T cells): a useful marker for megakaryocyte evaluation on bone marrow biopsies]. / LAT (linker for activation of T cells): un utile marcatore per l'identificazione di megacariociti in biopsie osteomidollari.

Detection of atypical megakaryocytes in bone marrow biopsies, especially in cases of myelodysplastic syndromes (MDS), chronic myeloproliferative disorders (CMPD) and acute leukemias, is facilitated by staining for markers such as Ulex europaeus agglutinin (UEA)-J, CD31, CD61 and von Willebrand factor (VWF), the latter being considered the most sensitive. Recently, LAT (linker for activation of T cells), a molecule involved in T-cell activation and platelet aggregation, was found to be expressed by megakaryocytes and platelets in tissue sections. We compared VWF and LAT immunoreactivity on megakaryocytes in 64 bone marrow biopsies from 12 normal controls (NC), and from patients with MDS (n=18), CMPD (n=21) and acute megakaryocytic leukemia (AML-M7, n=13). Immunostaining was performed on paraffin sections with polyclonal antibodies against VWF and LAT. Immunoreactivity was evaluated by counting positive megakaryocytes in 10 high-power fields, and values were compared using Student's t test for paired data. Both VWF and LAT predominantly stained the cytoplasm of megakaryocytes, although LAT was also recognizable on the cell membrane. In most biopsies, the immunoreactivity of the two antibodies was quite similar. No significant differences were noticed between the mean values of VWF+ and LAT+ megakaryocytes. However, in 22 cases (5 NC; 5 MDS; 6 CMPD; 6 AML-M7), the number of LAT+ megakaryocytes was at least 30% higher than VWF+cells, while in 3 cases opposite findings were found. In 3 AML-M7 cases, anti-LAT antibodies stained numerous megakaryocytes, but anti-VWF staining was practically negative; in another 5 AML-M7 cases, anti-LAT labeling was much stronger than anti-VWF staining. LAT represents a useful immunohistochemical marker for megakaryocytes in normal and pathological conditions. It seems to be expressed by megakaryocytes more than VWF in most cases and, particularly, in conditions associated with poorly differentiated megakaryocytes, such as acute megakaryocytic leukemias. The use of LAT staining should be recommended in association with other megakaryocyte markers in the study of bone marrow biopsies in cases of hematopoietic disorders.

Nonlymphoid intraepidermal mononuclear cell collections (pseudo-Pautrier abscesses): a morphologic and immunophenotypical characterization.

We evaluated the incidence, morphology, and immunophenotype of intraepidermal collections of mononuclear cells (ICMC) in a large number of inflammatory dermatosis and cutaneous lymphomas. ICMC appeared as small to large aggregates of cells, showing a morphology variable from monocytes to obvious dendritic cells, admixed with rare lymphocytes. ICMC were recognized in the epidermis or within hair follicle epithelium, and were either loosely or compactly arranged. ICMC were identified in 124 of 1,248 skin biopsies (9.9%) of inflammatory or lymphoid infiltrates, and were particularly frequent in spongiotic (43.4%) and in lichenoid dermatitis (10%), whereas they were rarely found in nonspecific superficial dermatitis (3.8%) and in psoriasis (4.7%). ICMC were also frequent in cutaneous T-cell lymphoma (13.3%), where they mimicked Pautrier abscesses. The ICMC forming cells showed a unique phenotype: the majority of them expressed CD1a and S-100, and lacked CD14, similar to mature Langerhans cells, but they were also strongly labeled by anti-CD11b, anti-CD36, and anti-CD68. Moreover, a subpopulation of them expressed CD83, an antigen that is usually absent on Langerhans cells. The occurrence of ICMC is a rather frequent, although hitherto poorly studied, phenomenon, occurring in several dermatosis, but particularly frequent in spongiosis-associated skin reactions. The cells within ICMC are represented by dendritic cells and dendritic cell precursors, whose phenotype indicates their derivation from circulating monocytes and differentiation into mature Langerhans cells.

Histopathological changes in bone marrow biopsies from patients with chronic myeloid leukaemia after treatment with recombinant alpha-interferon.

AIMS: Recombinant alpha-interferon (r-IFN) is an effective therapy for chronic myeloid leukaemia (CML), inducing haematological and major cytogenetic response in 70% and 30% of patients, respectively. In this study we have evaluated the significance of bone marrow (BM) histology on the subsequent response to r-IFN therapy, as well as the morphological changes induced by r-IFN within BM. METHODS AND RESULTS: 73 BM biopsies were studied from 21 patients with Ph1-positive CML in chronic phase at diagnosis and at different times during r-IFN treatment. At diagnosis the probability of achieving a major or complete cytogenetic response was significantly higher in patients with a total marrow cellularity lower than 90% (P = 0.02). During therapy with r-IFN, significant BM changes included disappearance of the CML pattern (P = 0.0002), reduction of M:E ratio (P = 0.0009) and total cellularity (P = 0.0027), and increase in number of terminal megakaryocytes (P = 0.0009) and of fatty tissue regeneration (P = 0.037); only after long-term therapy (mean 20 months), did reticulin fibrosis increase significantly (P = 0.032). CONCLUSIONS: The overall BM morphology in response to treatment displayed different pictures, ranging from persistence of CML (25 biopsies out of 51), to reversion to normal histology (14 out of 51). Persistence of diffuse morphological abnormalities was associated with lack of cytogenetic responsiveness (P = 0.025).

Specific skin infiltration as first sign of chronic myelomonocytic leukemia with an unusual phenotype.

A patient who had a plaque on his forehead as the first sign of chronic myelomonocytic leukemia (CMML) is described. Histologic studies, which formerly led to the misdiagnosis of non-Hodgkin's lymphoma, revealed CMML with an unusual phenotype. This represents a rare type of CMML for the following reasons: (1) specific cutaneous involvement is rarely the first sign of CMML; (2) the unique phenotype was detected by immunohistology on lesional skin, specifically, the leukemic infiltrate was CD4-positive and notably negative for CD15, the pan myeloid/monocytic marker.

Assessment of cell proliferation in normal and pathological bone marrow biopsies: a study using double sequential immunophenotyping on paraffin sections.

The proliferative activity of the haematopoietic and plasma cells in bone marrow was evaluated under normal and neoplastic conditions, by means of a sequential double immunostaining technique, using monoclonal antibody MIB-1 recognizing the cell proliferation-associated nuclear antigen Ki-67, and antibodies against glycophorin-C, myeloperoxidase, factor VIII-related antigen, and immunoglobulin light chains. Fifty-eight B5 fixed, paraffin-embedded bone marrow biopsies were analysed, including 11 normal controls. 10 cases of myelodysplasia, 14 cases of chronic myeloproliferative disorder, eight cases of acute non-lymphoid leukaemia, and 15 cases of myeloma. In normal marrows, the highest proliferative activity was noticed in the erythroid cells (75% to 95%; mean 90%), in comparison with myeloid precursors (15% to 80%; mean 38%), and megakaryocytes (10% to 20%; mean 14%): no Ki-67 positive plasma cells were found. In all investigated haematological disorders, the expression of MIB-1 by erythroid cells was similar to that observed in controls. Similarly, the percentage of MIB-1 + myeloid precursors in chronic myeloproliferative disorders and myelodysplasia largely overlapped the values observed in normals, and comparable values were also found in the blast cells from acute non-lymphoid leukaemia type M1 and M2. These findings suggest that the evaluation of either erythroid or myeloid proliferative activity is of little value in the differential diagnosis between these myeloproliferative disorders. By contrast, the obvious increase of Ki-67 expression of megakaryocytes in chronic myeloproliferative disorders, with labelling also of micro-megakaryocytes, might sustain the diagnosis in controversial cases. Since cases of mature myeloma showed less than 2% of Ki-67 positive cells, evaluation of proliferative activity is of no value in the differential diagnosis with reactive plasmacytosis. The sequential double immunophenotyping for Ki-67 antigen and for haematopoietic cell lineage-associated markers can be applied in a consistent manner to routine bone marrow biopsies to evaluate proliferating cells in normal and neoplastic conditions.

Pravastatin-associated myopathy. Report of a case.

A case of acute inflammatory myopathy associated with the use of pravastatin, a new hydrophilic 3-hydroxy-3 methylglutaril coenzyme A reductase inhibitor, is reported. The patient, a 69-year-old man was affected by non-insulin-dependent diabetes mellitus and hypertension. He assumed pravastatin (20 mg/day) because of hypercholesterolemia. He was admitted with acute myopathy of the lower limbs which resolved in a few days after pravastatin discontinuation. A previously unknown hypothyroidism, probably due to chronic autoimmune thyroiditis, was evidenced. Muscle biopsy (left gastrocnemius) revealed a perimysial and endomysial inflammatory infiltrate with a prevalence of CD4+ lymphocytes. While lovastatin and simvastatin have been associated with toxic myopathy, pravastatin-associated myopathy could represent a distinct, inflammatory entity.

Monoclonal expansion of large granular lymphocytes with a CD4+ CD8dim+/- phenotype associated with hairy cell leukemia.

Peripheral blood lymphoid cell expansions with an unusual CD3+, CD4+, CD8dim+/-, CD11b+, CD57+ immunophenotype have recently been reported. They frequently have the morphology of large granular lymphocytes (LGL) and can be either monoclonal or polyclonal. Their significance is still unclear and no association with hematological neoplasms has been described. We report the case of a patient with a monoclonal expansion of LGL associated with a B-cell-derived hairy cell leukemia. The two lymphoid clones were not physically associated since T-LGL were found in the peripheral blood and hairy cells were detected in the bone marrow and kidney.

Bridging nerve defects with combined skeletal muscle and vein conduits.

The use of vein or muscle grafts to bridge nerve defects longer than 1-1.5 cm gives poor results. Veins collapse and in muscle grafts axons may regrow outside the graft. We used veins (to guide regeneration) filled with muscle (to avoid vein collapse). Nerve regeneration through 1 and 2 cm grafts made of vein plus muscle was compared with similarly long traditional nerve grafts, free fresh muscle grafts, and empty vein grafts. Regeneration was assessed clinically and histologically (qualitative and quantitative evaluation) in the graft and distal nerve stumps. Vein plus muscle grafts were superior to vein and fresh muscle grafts both functionally and histologically. Functional results were similar to those found in traditional nerve grafts, but axon number was superior in the veins filled with muscle. This suggests that vein filled with muscle might serve as a grafting conduit for the repair of peripheral nerve injuries and could give better results than traditional nerve grafting.

Immunophenotypic characterization of the cell infiltrate in five cases of sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease).

Little is known about the nature of the large intrasinusoidal cells exhibiting cytophagocytosis, which are the histologic hallmark of sinus histiocytosis with massive lymphadenopathy (SHML) (Rosai-Dorfman disease). Using a broad panel of monoclonal and polyclonal antibodies, we analyzed the immunophenotype of the cell infiltrates in seven lymph node biopsy specimens from five cases of SHML. The SHML cells constantly expressed the S-100 protein, concanavalin agglutinin and peanut agglutinin lectins, and monocyte-macrophage-associated antigens CD 11c, CD 14, CD 33, CD 68, and LN 5. Labeling with other antimacrophage antibodies was extremely variable, with some (MAC 387, lysozyme) restricted to clusters of SHML cells and others (CD11b, CD 36, alpha-1-antichymotrypsin) staining only scattered cells. The CD 1a antigen was found on some cells in only one case, whereas HLA-DR and the HLA-DR-associated invariant chains were absent. The heterogeneity of SHML cell marker expression might be related to the local content of factors (eg, cytokines) capable of modulating the phenotype of monocytes and derived cells. All cases presented with huge amounts of medium-sized mononuclear cells accumulated in the sinuses and intersinusoidal tissue. These cells expressed the S-100-/CD 11b+/CD 11c+/CD 14+/CD 16+/CD 33+/CD 36+/lysozyme+/MAC 387+/HLA-DR+ phenotype. These recently immigrated monocytes might represent the immediate precursors of SHML cells.

[Eosinophilic gastritis. Clinico-pathologic considerations on a case and review of the literature]. / Gastrite eosinofila. Considerazioni clinico-patologiche su di un caso e revisione della letteratura.

The clinical, radiographic and histological features of a case of eosinophilic gastritis in a 26 year old-man without personal or familial signs of allergy are reported. The Authors pointed out the importance of radiographic and histological aspects of the case studied. Therefore they represent essential methods for a correct diagnosis and an appropriate management that in this case is only pharmacological. The diagnosis of eosinophilic gastritis is, however, important for the recognition of specific allergens.

[The gastrointestinal tract in H.I.V. patients. Anatomopathologic aspects of opportunistic infections]. / Il tratto gastrointestinale in pazienti H.I.V. Aspetti anatomo-patologici delle infezioni opportuniste.

The symptoms of the Acquired Immuno-Deficiency Syndrome (A.I.D.S.) in the gastrointestinal tract are principally represented by neoplastic processes (Kaposi's sarcoma, lymphoma) and by opportunistic infections. These infections, for the diversity of bacterial, viral or parasitic etiological agents which are involved, ask for new and more specific interpretative problems, from the pathological point of view-either in the identification of the pathogenic agents either in the recognition of infective lesions associated with the presence of a not directly objectivable infective agent. On the basis of these considerations the authors report the principal histopathological characteristics connected with opportunistic infections of the gastrointestinal tract in 18 H.I.V. positive patients. Of every segment of the gastrointestinal tract, the detected agents are described with the lesions related to them, the other not specific A.I.D.S. associated infective forms recently described in literature, and in particular the differential diagnostic problems connected with viral infections. In the large bowel must be underlined the problems and the principal distinctive elements between opportunistic agents derived colitis and idiopathic colitis.