Scale-dependent effects of vegetation on flow velocity and biogeochemical conditions in aquatic systems.

In rivers, scale-dependent feedbacks resulting from physical habitat modifications control the lateral expansion of submerged plant patches, while the mechanisms that limit patch expansion on a longitudinal dimension remain unknown. Our objective was to investigate the effects of patch length on physical habitat modification (i.e.

Concurrence of chronic lymphocytic leukaemia/small lymphocytic lymphoma and acute myeloid leukaemia in a bone marrow biopsy.

The association of small lymphocytic lymphoma/chronic lymphocytic leukaemia (CLL) with different malignancies has been reported in the literature. Also the occurrence of a second haematological disease has been described, more frequently as a secondary event in patients receiving chemotherapeutic agents. We report a case of CLL with concurrent acute myeloid leukaemia in an untreated patient, with emphasis on the need of a detailed immunomorphological study to identify the coexistence of the two diseases in the same pathological tissue.

Onset and Progression of Precancerous Lesions on Gastric Mucosa of Patients Treated for Gastric Lymphoma.

Background And Aims: Patients with primary gastric lymphoma are at an increased risk of developing gastric cancer. Data on gastric precancerous lesions development in these patients are scanty. We assessed gastric precancerous lesions in a cohort of patients with primary lymphoma.

Duodenal localization of plasmablastic myeloma.

Gastrointestinal involvement in plasma cell neoplasms, either as primary localizations (extramedullary plasmacytomas) or as secondary involvement in systemic multiple myeloma, is a well-known event. Accurate histological examination is crucial in defining the diagnosis. In this report, an uncommon case of duodenal localization of myeloma with plasmablastic features is described, with emphasis on the role of clinical data and findings from ancillary immunostaining techniques to avoid misdiagnosis.

Primary intrathymic lymphangioma.

Objectives: Lymphangiomas are relatively uncommon lesions of the lymphatic channels that can arise in virtually any part of the body provided by lymphatic vessels. The most common localization is the head/neck region, with only sporadic reports in other sites. The mediastinum is a rare location, with around 20 cases reported in the literature.

Low-grade myofibroblastic sarcoma of the larynx.

Low-grade myofibroblastic sarcoma is an uncommon sarcoma with myofibroblastic differentiation. It occurs in a wide variety of sites and has a predilection for the head and neck region. Biologically, low-grade myofibroblastic sarcoma has a propensity for local recurrence and is associated with a low risk of metastatic spread.

A minute focus of extranodal marginal zone B-cell lymphoma arising in Hashimoto thyroiditis diagnosed with PCR after laser capture microdissection: a case report.

Background: Primary thyroid gland lymphomas are uncommon tumours that occur in the setting of lymphocytic thyroiditis or Hashimoto's disease in almost all cases. In this condition a distinction between an inflammatory lymphoid infiltrate and a low grade lymphoma may be extremely difficult and precise criteria are necessary for a correct diagnosis.

Patient And Methods: We report a case of a minute focus of primary extranodal marginal zone B-cell lymphoma (EMZBCL), incidentally discovered in a 63-year-old man with Hashimoto thyroiditis (HT) and diagnosed by means of polymerase chain reaction (PCR) after laser capture microdissection.

Cytogenetic evidence of metastatic myxoid liposarcoma and therapy-related myelodysplastic syndrome in a bone marrow biopsy.

Myxoid liposarcoma exhibits a peculiar clinical behavior, with a tendency to spread to serosal membranes, distant soft tissues, and bones, even in the absence of lung metastases. Therapy-related hematological neoplasms are well-known side effects of cytotoxic chemotherapy. We describe an exceptional case of metastatic myxoid liposarcoma of the spine associated with therapy-related refractory anemia with excess of blasts in a 37-year-old woman who underwent multi-agent chemotherapy for a myxoid liposarcoma of the left thigh.

Russell body gastritis associated with Helicobacter pylori infection in an HIV-positive patient: case report and review of the literature.

In 1998 Tazawa and Tsutsumi described for the first time a case of Helicobacter pylori (HP)-related gastritis characterized by the presence of a conspicuous plasma cell infiltrate with Russell bodies, and coined the term Russell body gastritis (RBG). A 59-year-old HIV-positive man complaining of recurrent epigastric pain underwent an upper gastrointestinal endoscopy revealing in the stomach only hyperemia in the antral portion. Histology showed a moderate glandular atrophy associated with an expansion of the lamina propria due to an infiltration of monomorphous cells with eosinophilic cytoplasm inclusions and eccentric nuclei, somewhat resembling plasma cells.

Primary myxopapillary ependymoma of the cerebellopontine angle: report of a case.

Myxopapillary ependymoma is a rare variant of ependymoma, almost exclusively occurring in the region of the cauda equina and filum terminale. We describe a myxopapillary ependymoma located in the left cerebellopontine angle of a young man suffering from peripheral vertigo and left sensorineural hearing loss for years. The patient underwent surgical removal of the tumour.