Search

Targeted therapy has become an integral part of treatment procedures of malignant tumors. Colorectal carcinomas are frequently targeted with monoclonal anti-EGFR antibodies (cetuximab and panitumumab). Activating somatic mutations in codons 12 and 13 of the exon 2 of KRAS gene are considered negative predictive factors of response to anti-EGFR therapy in patients with metastatic colorectal cancer. In the Czech Republic, evaluation of mutational status of KRAS gene is performed in several referral laboratories. In 2009, these laboratories performed 2580 tests of the KRAS mutational status--out of these, 60.2% cases reported non-mutated, wild-type KRAS. In one of the referral laboratories, we demonstrate the logistics of KRAS testing procedure. Stratification of patients with metastatic colorectal tumors based on their KRAS mutational status has evolved to a standard procedure. Laboratories performing these methods shall therefore adhere to the recommendations of the professional and accredited societies.

We report a case of an 86-year-old female with a tubulo-squamous polyp of the vagina. Grossly, the polyp measured 2 x 1.5 x 1 cm. Histologically, it was composed of well-circumscribed nests of squamous cells with bland nuclei. Some of the squamous nests showed central spaces filled with necrotic debris. Small tubules were present at the periphery of some of the nests, and there were a few tubules unassociated with the squamous nests. Furthermore, several larger mucinous glands, some with apparent squamous metaplasia, were present. The stroma was fibrous and rather hypocellular. Surface of the polyp was covered by intact squamous epithelium, which was not connected with the underlying lesion. The recently described tubulo-squamous vaginal polyp represents a distinctive entity. To the best of our knowledge, only one study describing a series of ten cases has been reported in the literature to date.

The kidneys are one of the most frequent sites of amyloid deposition during systemic AL, AA, and several hereditary amyloidoses. Distinguishing between different forms of amyloids is clinically important because of their different treatment.We present a 5-year retrospective study of amyloidoses diagnosed in renal biopsy samples. The classification of amyloidosis was made by immunofluorescence and immunohistochemical staining with antibodies to kappa and lambda immunoglobulin light chains, and for serum amyloid A protein.From January 2003 to December 2007, 996 renal biopsy samples from one centre were evaluated. Amyloidosis was diagnosed in 62 samples (6.2%); 33 (53.2%) were classified as AL and 25 (40.3%) as AA amyloidosis. Four cases have remained unclassified. We did not identify any difference in the distribution of deposits among cases with AL and AA amyloidosis, respectively. The majority of patients underwent the renal biopsy due to severe proteinuria or nephrotic syndrome. Three patients had very low proteinuria, less than 0.5 g/day. Diagnosis of amyloidosis was suspected by nephrologists in 48 patients (77.4%).Diagnosis of amyloidosis involves detection of amyloid deposits and classification of the amyloid form, which represent the basic step for appropriate therapy. Altogether it is not an easy task for pathologists, and with the emergence of markedly different treatments depending on the specific type of amyloid, the precise typing is of increasing clinical importance and should be performed with great care. Immunofluorescence can be very useful in daily practice for classification of the type of amyloidosis.

Interstitial cystitis is a chronic, non-bacterial inflammatory disorder of the wall of the urinary bladder and it manifests with very painful symptoms. Initially it can resemble a bacterial inflammation of the urinary bladder. This syndrome is characterised with motor and sensory dysfunction of the urinary bladder. The difficulties can be classified into so-called syndrome of the chronic pelvic pain. Increasing incidence, chronicity of this disorder and specific treatment leads to the reinterpretation of the chronic inflammation of the urinary tract diagnosed in the past and to the modification of the treatment of these patients. Because of the polymorphic difficulties and the psychosomatic manifestations, IC can lead to invalidity of the patient.

Glomus tumor is a benign soft tissue neoplasm which commonly affects the subungual region of the fingers. But the tumors can also arise in the other sites such as the antrum of the stomach. We are reporting a case of a glomus tumor of the stomach in a 71-year-old female patient who presented with dyspepsia. The tumor was confined to the lamina muscularis propria, it consisted of round cells with small uniform nuclei, which surrounded thin walled blood vessels. Immunohistochemistry revealed the tumor to be positive for smooth muscle actin, vimentin, calponin, h-caldesmon and negative for c-KIT, S-100, CD34, CD99, synaptophysin, chromogranin, desmin and EMA. The proliferation marker Ki-67 was positive in less than 5% of tumor cell nuclei. Glomus tumors are usually benign but malignant cases have been published. Criteria for the malignant potential of gastric glomus tumors remain poorly defined.

We studied the results of immunostaining for S-100 protein, alpha-smooth muscle actin, muscle specific actin and desmin in articular cartilage specimens obtained during an arthroscopy from eight patients with different degrees of osteoarthritis of the knee joint. In all cases, most of the cartilage cells were strongly positive for S-100 protein. Actin positive chondrocytes were present in four samples showing repair cartilage changes with occurrence of fibrocartilage tissue. Moreover, in one case, we observed typical desmin-positive chondrocytes in the layer of cartilage filling the defect of the articular cartilage surface. The expression of desmin can be regarded as a reaction to trauma or the indication of an inherent abnormality. The chondrocytes probably switched on smooth muscle features during the healing process, because desmin is to a great extent a typical muscle cell marker. This fact could probably support our previous supposition that cartilage cells expressing muscle markers could be designated as myochondroblasts and myochondrocytes analogously to the terminology of myofibroblasts. It is possible that during the healing of the cartilage defects, such a transformation of the immunophenotype of the cartilage cells is quite frequent, but it could also be only transient nature only.

Ewing's sarcoma is relatively uncommon tumor representing 6-8 percent of malignant bone tumors with variable morphology. Cytogenetically, Ewing's sarcomas are characterized by a specific reciprocal chromosomal translocation t(11;22)(q24;q12). The presence of this chromosomal translocation has been detected in approximately 85 percent of the cases. The translocation results in the fusion of EWS gene from chromosome 22 to FLI1 gene at 11q24 which is a member of ETS family of transcription factors. In this study we performed a comparison of two molecular diagnostic strategies, namely RT-PCR and FISH, in fresh, frozen and formalin-fixed paraffin-embedded tissues. We conclude that FISH is a more sensitive technique than RT-PCR for the diagnosis of Ewing's tumors in formalin-fixed paraffin-embedded tissue. In conclusion, molecular pathology techniques, using reverse transcription-polymerase chain reaction (RT-PCR) and/or fluorescence in situ hybridization (FISH) are valuable diagnostic tools for evaluation of undifferentiated small round-cell tumors like Ewing's sarcoma.

We report three cases of leiomyoma of the gastrointestinal tract with intracytoplasmic inclusion bodies similar to those characteristic of inclusion body fibromatosis (IBF). The first two cases represent leiomyoma of the stomach: one in a 70-year-old female and the other in a 72-year-old female. In both instances inclusion bodies were present in a large amount. In the third case the leiomyoma was located in the esophagus of a 63-year-old male and inclusion bodies in this case were rare. In all three cases an immunohistochemical analysis showed positivity of the tumor cells for muscle specific actin HHF35 (MSA), alpha-smooth muscle actin (SMA), h-caldesmon and desmin. The first case showed some inclusion bodies with positivity for cytokeratin CAM 5.2 and focal weak positivity for cytokeratin 18. In the second case the inclusion bodies were positive at the periphery with antibodies directed against MSA and SMA. In the third case the inclusion bodies were immunohistochemically entirely negative. Ultrastructurally, the inclusion bodies in the first case were composed of aggregated filaments, some with entrapped cytoplasmic organels and others with finely granular dense cores.

A programme for controlled automated histomorphometric evaluation of bone biopsies, connected with authors' results with semiautomated program, introduces new technology as well as new principle. It is based on a digitalization of microscopic picture in videocamera followed by controlled automated computerized processing of the picture. A further simplification of the evaluation process is achieved by eliminating a time consuming and not quite precise over-drawing of the picture on a digitalization desk.

The expression of alpha smooth muscle actin, muscle specific actin, desmin, h-caldesmon, and calponin was studied immunohistochemically in the following soft tissue and bone tumours and tumour-like lesions: muscle fibromatosis, inflammatory pseudotumours, chondroblastoma, enchondroma, chondrosarcoma, fibrous dysplasia, ossifying myositis, osteoblastoma, convential osteosarcoma, leiomyoma and leiomyosarcoma. Tumours and tumour-like lesions with myofibroblastic cells, osteoblasts and chondroblasts frequently exhibited intensive immunoreactivity for the muscle markers, and therefore, some of them may occasionally be confused with leiomyoma and leiomyosarcoma. Calponin does not help to differentiate various mesenchymal tumours expressing muscle markers, because it also stains intensively myofibroblasts, osteoblasts and chondroblasts. We confirmed that h-caldesmon was expressed intensely in leiomyomas and leiomyosarcomas, and never in the other tumours examined, with the exception of three chondroblastomas. The results have shown that h-caldesmon is a rather specific and sensitive marker for smooth muscle tumours, but it can also stain some actin positive myochondroblasts. It is possible that the positivity of h-caldesmon in some chondroblastomas is due to their complete myogenic transdifferentiation, and so we use the term myochondroblasts and myochondrocytes for designation of such S-100 protein, actin, and h-caldesmon positive cells.