Biomedical subjects

R Valli

Publications and source records attributed to R Valli.

5 recordsLinked to original sources

PubMed2005

PDGFR expression in differential diagnosis between KIT-negative gastrointestinal stromal tumours and other primary soft-tissue tumours of the gastrointestinal tract.

AIMS: To investigate the value of platelet-derived growth factor receptors (PDGFRs) by immunohistochemistry in discriminating KIT-negative gastrointestinal stromal tumours (GISTs) from other soft-tissue neoplasms of the digestive tract. METHODS AND RESULTS: One-hundred and sixty-seven primary gastrointestinal mesenchymal tumours (125 GISTs, 15 intra-abdominal desmoids, 12 leiomyomas, eight leiomyosarcomas, three schwannomas, two solitary fibrous tumours, and one case each of inflammatory pseudotumour and fibroid polyp) were reclassified based on morphology and on the immunohistochemical panel recommended by the National Institutes of Health consensus on GIST. All cases were then tested with antibodies specific for PDGFR alpha and beta. Of 125 GISTs, 117 were KIT-positive (93.6%) and eight KIT-negative (6.4%). All the KIT-positive GISTs were negative for both PDGFRs, while all the eight KIT-negative GISTs expressed PDGFR-alpha, with two of them also coexpressing PDGFR-beta. Among the 42 non-GIST tumours, only a small percentage (26.6%) of desmoids immunostained for PDGFR-alpha, two of them coexpressing PDGFR-beta. CONCLUSIONS: Immunostaining with PDGFR-alpha is a helpful marker in discriminating between KIT-negative GISTs and other gastrointestinal mesenchymal lesions: all KIT-negative GISTs were positive for PDFGR-alpha, while none of the other gastrointestinal mesenchymal tumours analysed, except a small subset of desmoids, was reactive with anti-PDGFRs. These preliminary data demonstrate the suitability of commercially available antibodies to detect immunohistochemically the mutually exclusive expression of KIT and PDGFR-alpha previously reported in GISTs by molecular biological techniques. Since PDGFR exists in the form of a homodimer (alphaalpha, betabeta) or heterodimer (alphabeta) and two of the KIT-negative GISTs coexpressed both PDGFR isoforms, further investigations are required to elucidate the role of PDGFR-beta in GISTs.

Adult↗

PubMed2005

The value of c-kit mutational analysis in a cytokeratin positive gastrointestinal stromal tumour.

The expression of cytokeratins in gastrointestinal stromal tumours (GISTs) is rare and may lead to diagnostic confusion when it occurs. This report describes a metastatic GIST that stained strongly for cytokeratins, CD117, and CD34 in a patient who was previously diagnosed with gastric epithelioid angiosarcoma. A review of both tumours showed the same histological and immunohistochemical profiles, and c-kit molecular analysis revealed an insertional mutation at codon 558 of exon 11 in both tumours. Thus, pathologists should be aware that GISTs can occasionally express cytokeratins, and that c-kit mutational investigations may have a key diagnostic role and may prevent diagnostic mistakes that could have important clinical implications.

Adult↗

PubMed2003

Thyroid abscess associated with a substernal goiter. Case report.

An abscess associated with an intrathoracic goiter is an extremely rare condition. The authors report a case of a thyroid abscess complicated by acute dyspnea and asphyxia in a patient of geriatric age with a substernal goiter. Surgical therapy was necessary to obtain a correct diagnosis and an effective treatment.

Abscess↗

PubMed2002

[Dermatofibrosarcoma protuberans of the breast: a case report].

We describe a dermatofibrosarcoma protuberans (DFSP) of the breast and briefly report about such cases previously mentioned in the literature. A 27-year-old woman was referred because of the progressive increase, during pregnancy, of a mammary nodule located between the internal quadrants of the right breast. Its clinical and radiologic features suggested a fibroadenoma. Lumpectomy revealed a 3-cm, gray-whitish, fasciculated nodule. Histological examination showed a neoplasm characterized by a highly and monomorphic cellular proliferation of spindle-shaped cells, arranged in bundles displaying repetitive storiform growth pattern and infiltrating the adjacent mammary tissue. Lack of necrosis and low mitotic rate was observed. At immunohistochemistry the tumor cells were diffusely positive for vimentin and CD34, but negatively stained with CD99, bc-2, desmin, smooth-muscle actin, S100 protein and cytokeratins. A diagnosis of mammary dermatofibrosarcoma protuberans (DF-SP) was posed. Neoplastic involvement of surgical margins led to a subsequent quadrantectomy without regional lymphadenectomy. The patient was alive and disease-free at the 8-month follow-up. Mammary DFSP is rare. Its preoperative diagnosis is extremely difficult, particularly when radiologic images show an intraparenchymal lesion with round borders. We report such a case and briefly review the pertinent literature. Morphologic parameters to distinguish DFSP from other spindle cell lesions of the breast are discussed.

Adult↗

PubMed2001

[Parosteal rib lipoma: description of a case].

Parosteal lipoma is a usually indolent, rare benign tumor, characterized by clinicopathological findings similar to those of the commonly occurring subcutaneous lipoma, except for its intimate relationship with the connective tissue of the subjacent periosteal region. Parosteal lipoma commonly affects the diaphysis of long bones of the upper and lower limbs. We report an exceedingly rare case of parosteal lipoma of the rib, which presented in a 59-year-old man experiencing previous multiple traumas in this site.

Bone Neoplasms↗