The t(2;5)(p23;q35) translocation, associated with anaplastic large-cell lymphoma (ALCL), results in the expression of a chimeric NPM-ALK protein that can be detected by the ALK1 monoclonal antibody. This report describes the morphologic and phenotypic spectrum of 123 cases of lymphoma that all express ALK protein. The results provide strong evidence that the morphologic patterns of ALCL described in previous reports as representing possible subtypes of ALCL, eg, common type, lymphohistiocytic, or small cell patterns, are morphologic variants of the same disease entity. All of these morphologic patterns could be found within this series, and in some patients different subtypes coexisted in a single biopsy or were found in successive biopsies from a single patient. The link between these morphologic subtypes is further reinforced by the presence in all cases of a highly characteristic large cell, with an eccentric nucleus and an eosinophilic paranuclear region. We suggest that this cell can be considered as a major distinguishing feature of ALK-positive lymphomas. Another characteristic of these tumors was the perivascular pattern of neoplastic cell infiltration seen in a significant number of cases. In addition to ALK protein, all tumors expressed epithelial membrane antigen and lacked CD15, features that may be of value in differentiating ALCL from Hodgkin's disease. In the majority of cases (84%), malignant cells showed both a cytoplasmic and nuclear staining for ALK1 and thus presumably carried the 2;5 translocation, but staining was restricted to the cytoplasm in a few cases, suggesting that translocations other than t(2;5) may induce expression of ALK protein. We conclude from this study that ALK-positive neoplasms represent a distinct entity. Because their morphology is often neither anaplastic nor large cell, we suggest that they should henceforward be referred to as ALK lymphomas.

The t(2;5)(p23;q35) translocation, associated with anaplastic large-cell lymphoma (ALCL), results in the expression of a chimeric NPM-ALK protein that can be detected by the ALK1 monoclonal antibody. This report describes the morphologic and phenotypic spectrum of 123 cases of lymphoma that all express ALK protein. The results provide strong evidence that the morphologic patterns of ALCL described in previous reports as representing possible subtypes of ALCL, eg, common type, lymphohistiocytic, or small cell patterns, are morphologic variants of the same disease entity. All of these morphologic patterns could be found within this series, and in some patients different subtypes coexisted in a single biopsy or were found in successive biopsies from a single patient. The link between these morphologic subtypes is further reinforced by the presence in all cases of a highly characteristic large cell, with an eccentric nucleus and an eosinophilic paranuclear region. We suggest that this cell can be considered as a major distinguishing feature of ALK-positive lymphomas. Another characteristic of these tumors was the perivascular pattern of neoplastic cell infiltration seen in a significant number of cases. In addition to ALK protein, all tumors expressed epithelial membrane antigen and lacked CD15, features that may be of value in differentiating ALCL from Hodgkin's disease. In the majority of cases (84%), malignant cells showed both a cytoplasmic and nuclear staining for ALK1 and thus presumably carried the 2;5 translocation, but staining was restricted to the cytoplasm in a few cases, suggesting that translocations other than t(2;5) may induce expression of ALK protein. We conclude from this study that ALK-positive neoplasms represent a distinct entity. Because their morphology is often neither anaplastic nor large cell, we suggest that they should henceforward be referred to as ALK lymphomas.

The role of IL-1 in susceptibility to Streptococcus pneumoniae infection was studied in mice deficient in genes of the IL-1 family [i.e. IL-1alpha-/-, IL-1beta-/-, IL-1alpha/beta-/- and IL-1R antagonist (IL-1Ra)-/- mice] following intra-nasal inoculation. Intra-nasal inoculation of S. pneumoniae of IL-1beta-/- and IL-1alpha/beta-/- mice displayed significantly lower survival rates and higher nasopharyngeal and lung bacterial load as compared with control, IL-1alpha-/- and IL-1Ra-/- mice. Treatment of IL-1beta-/- mice with rIL-1beta significantly improved their survival. A significant increase in blood neutrophils was found in control, IL-1alpha-/- and IL-1Ra-/- but not in IL-1beta-/- and IL-1alpha/beta-/- mice. Local infiltrates of neutrophils and relatively preserved organ architecture were observed in the lungs of IL-1alpha-/- and control mice. However, S. pneumoniae-infected IL-1beta-/-, IL-1alpha/beta-/- and IL-1Ra-/- mice demonstrated diffuse pneumonia and tissue damage. Altogether, all three isoforms contribute to protection against S. pneumoniae; our results point to differential role of IL-1alpha and IL-1beta in the pathogenesis and control of S. pneumoniae infection and suggest that IL-1beta has a major role in resistance to primary pneumococcal infection while the role of IL-1alpha is less important.

Osteoblastic osteitis is a rare kind of bone infection typified by a proliferative reaction of the periosteum and by exuberant bone formation. In the maxillary sinus, it occurs as a consequence of chronic or recurrent sinusitis. It usually manifests with a vague facial discomfort, followed by complications in the deep facial spaces or fossae. The diagnosis is a radiological one. Eradication of this bone infection necessitates removal of the precipitating condition as well as the long-term administration of appropriate anti-biotics. In the case of a deep facial fossae abscess, drainage is mandatory.

Little is known of the role of preliminary corticosteroids in clinical and morphological modifications and in difficulties in reaching a diagnosis in patients with lymphoma. We identified 31 patients who were given steroids before biopsy for primary diagnosis. We looked for the reason for steroid pretreatment, its dose, and duration. We evaluated the difficulty in reaching the primary diagnosis and whether a secondary diagnosis was made. The patients' slides were reviewed to identify secondary histological changes. Our findings suggest a variable effect of prior glucocorticoids on the clinical and histopathological alterations developing in malignant lymphomas, as well as on the complexity of the process of reaching a diagnosis.

The characteristics of spinal injury in women, as opposed to men, stand out as divergent. The mechanisms of trauma and the site of injury differ significantly. We suggest this variance may be due, in part, to skeletal and muscular structure dissimilarity in women and in part to the spinal kinematics attending each group.

The clinicopathologic findings in a patient who developed dysphagia and obstruction of the middle third of the esophagus 12 years after mastectomy for breast carcinoma are presented. Endoscopic biopsy revealed metastatic breast carcinoma with pseudoepitheliomatous hyperplasia of the overlying esophageal mucosa. To the best of our knowledge, the case represents the first reported association between esophageal metastasis and pseudoepitheliomatous hyperplasia of the esophageal squamous epithelium.

Extraovarian Brenner tumors are extremely rare. We report a case of vaginal Brenner tumor occurring in an 84-year-old woman. The tumor presented with vulvar irritation and soreness and consisted of a 1.8-cm polypoid mass arising from the lower third of the vagina. Microscopically, it had all the 3 components--urothelial islands, glands, and fibrous stroma--characteristic of a Brenner tumor. We suggest that vaginal Brenner tumors arise from a metaplastic process within the mullerian epithelium.