[A giant gastrointestinal stromal tumour - a case report]. / Obrovský gastrointestinální stromální tumor - kazuistika.

Gastrointestinal stromal tumours represent a group of non-epithelial gastrointestinal tumours that have both benign and malignant character. Most frequently, they occur in the stomach and the intestine; however, as regards their overall incidence, they are rather infrequent tumour lesions. The present case report describes a rare bulky extragastrointestinal stromal tumour originating from the mesenterium in a young patient. Its anatomical and histological picture, diagnosis and treatment are described. Our work points to the necessity for physicians to also bear in mind the less likely options and highlights the role of surgery in the treatment of such voluminous findings.

[Predictive factors for non-sentinel lymph nodes affection in breast carcinoma--outcomes of a Czech multicenter study of sentinel lymph nodes]. / Prediktivní faktory postizení nonsentinelových uzlin u karcinomu prsu--závery ceské multicentrické studie sentinelových uzlin.

BACKGROUND: The aim of the study was to assess positivity nonsentinel lymph nodes in patients with macro, micro and submicrometastases in sentinel lymph nodes and find predictive factors of positivity nonsentinel lymph nodes. Study was conducted at the Department of Surgery in Pardubice, Pilsen, Ostrava and Zlín. MATERIAL AND METHODS: Sentinel lymph nodes were assessed based on standards of Czech Pathological Society. Detection of sentinel lymph nodes was performed based on radionavigation or combination of radionavigation and blue dye method. RESULTS: In group N1 (macrometastases) there was found positivity of nonsentinel lymph nodes in 50% (45 from 90 patients). In group N1 Mi (micrometastases) there was found positivity of nonsentinel lymph nodes in 26.7% (16 from 60 patients). In group NO I+ (sub-micrometastases) there was found positivity of nonsentinel lymph nodes in 6.7% (1 from 15 patients). Predictive factors were size of metastasis, number of positive sentinel lymph nodes and grading. Size of tumor was not found to be a predictive factor of positivity nonsentinel lymph nodes. DISCUSSION: High positivity of nonsentinel lymph nodes in pacients with macro and micrometastases in sentinel lymph nodes advocates to perform axillary lymph nodes dissection. Due to small number of patients with submicrometastases it is not possible to assess if axillary dissection is necessary or not. Predictive factors of positivity of nonsentinel lymph nodes are size of metastasis in sentinel lymph nodes, number of positive sentinel lymph nodes and grading. Size of tumor was not found to be a predictive factor due to small tumors in the study. In spite of this it is necessary to consider it like a predictive factor of positivity nonsentinel lymph nodes. CONCLUSION: In patients with macro and micrometastases it is necessary to perform axillary dissection. In patients with submicrometastases in sentinel lymph nodes it is necessary to consider predictive factors.

Muscle-specific actin expression in chondroblastomas.

Chondroblastomas are unusual cartilage benign lesions of bone that have well-characterized histological features. We reviewed and immunohistochemically examined the paraffin block material of 20 cases, and in seven tumors of this collection we found distinct cytoplasmic muscle-specific actin positivity of some tumor chondroblasts and chondrocytes. Muscle-specific actin-positive cells had the histological and ultrastructural features typical of chondroblasts. Moreover, in their cytoplasm they contained bundles of microfilaments with focal densities, as is typical of myofilaments. We did not observe any basal lamina around these cells, which were surrounded by intercellular matrix of the cartilage tissue type. Therefore, we suppose that muscle-specific actin-positive cells occurring in some chondroblastomas do not represent an admixture of myofibroblasts but chondroblasts with actin expression. The unusual immunophenotype of some chondroblasts might be the result of aberrant actin expression or of the plasticity of their phenotype modulated by microenvironmental stimuli. It is a question of whether, analogously to the terminology of myofibroblasts, such cells could be designated as myochondroblasts.

Histiocytosis of regional lymph nodes associated with hip replacement.

Five cases of pronounced histiocytic reaction in pelvic lymph nodes after hip replacement are demonstrated. Two patients subsequently underwent radical prostatectomies with bilateral lymph node dissections for adenocarcinoma. In three patients, the change was found during autopsy. The sinuses and interfollicular spaces were distended by numerous large macrophages that had bulky eosinophilic cytoplasm. The cells displayed immunoreactivity to KP1 antigen, alpha-1-antitrypsin and lysozyme, providing support for their histiocytic derivation. Polarization microscopy revealed birefringent needle-like particles in their cytoplasm. We think that the histologic appearance of lymph nodes represents a foreign body reaction to fragments of polyester or polyethylene derived from joint prostheses. It is necessary to be aware of this characteristic foreign body reaction in order to avoid confusion with other types of lymph node histiocytosis or with a metastatic tumor.