[Solitary fibrous hemangiopericytoma of atypical location: importance of immunohistochemical study]. / Tumor fibroso solitario hemangiopericitoma de localización atípica: importancia del estudio inmunohistoquímico.

BACKGROUND: The rare cutaneous solitary fibrous tumor was initially described in the thoracic cavity in relation to the pleura and subsequently been associated with other serous membranes. It has been described in other extraserosal locations including the skin. Knowledge of its existence along with fairly typical histological features and the immunohistochemical expression pattern with intense positivity for CD34 allow the increasing diagnosis of this condition, which suggests that these cases were not previously diagnosed as such. CLINICAL CASE: We report the case of a 43 year-old male with a painless nodule in the first left finger pad clinically suggestive of pyogenic granuloma or nodular melanoma, which was diagnosed by excisional biopsy and immunohistochemical study as a solitary fibrous tumor. DISCUSSION: Only 11 cases of cutaneous solitary fibrous tumor have been published in the following locations: head, cheek, thigh, chest, back and nose. Our work describes the first case of cutaneous solitary fibrous tumor in the hand. The solitary fibrous tumor derived from mesenchymal cells expresses CD34 and hence its presentation in any location. In our case it was in the hand. It explains the problems encountered in the clinical differential diagnosis with other tumors as nodular melanoma, pyogenic granuloma, giant cell tumor of tendon sheath, fibroma, benign peripheral nerve sheath tumors, etc. As we consider the histology, differential diagnosis should be made with other tumors that also express CD34. CONCLUSIONS: Solitary fibrous tumors derived from mesenchymal cells express CD34 and hence its presentation in any location. In our case it was in the finger pad.

Antecedentes: el tumor fibroso solitario es un tumor poco común. Anteriormente se suponía que afectaba sólo la cavidad torácica, en especial la pleura; posteriormente, se relacionó con otras membranas serosas y se observó en diversas localizaciones extraserosas, entre ellas la piel. El conocimiento de este tumor, junto con el aspecto histológico característico y el patrón de expresión inmunohistoquímica con intensa positividad para CD34 permiten que cada vez se diagnostique con mayor frecuencia. Caso clínico: se comunica el caso de un varón de 43 años de edad con un nódulo indoloro en el pulpejo del primer dedo izquierdo, que sugería clínicamente un melanoma nodular o granuloma piógeno. Mediante biopsia excisional y estudio inmunohistoquímico se diagnosticó como tumor fibroso solitario. Discusión: hasta la fecha se han publicado 11 casos de tumores fibrosos solitarios cutáneos, localizados en cabeza, mejilla, muslo, pecho, espalda y vestíbulo nasal. El caso que se comunica constituye la primera lesión de estas características que afecta la mano. El diagnóstico clínico diferencial del tumor fibroso solitario incluye otros tumores como: melanoma nodular, granuloma piógeno, tumor de células gigantes tenosinovial, fibroma y tumor de vaina de nervio periférico benigno. En cuanto a la histología, se planteó el diagnóstico diferencial con otras neoplasias que también expresan CD34. Conclusiones: el tumor fibroso solitario deriva de células mesenquimatosas y expresa CD34, lo que explica su aparición en cualquier localización, como en este caso, que fue en el pulpejo del quinto dedo.

Calcifying Cystic Odontogenic Tumour: immunohistochemical expression of matrix metalloproteinases, their inhibitors (TIMPs and RECK) and inducer (EMMPRIN).

BACKGROUND: Calcifying cyst odontogenic tumour (CCOT) is a rare benign cystic neoplasm of odontogenic origin. MMPs are responsible for extracellular matrix remodelling and, together their inhibitors and inducer, determinate the level of its turnover in pathological processes, leading to an auspicious microenvironment for tumour development. Thus, our goal was to evaluate matrix metalloproteinases (MMPs-2, -7, -9 and -14), their inhibitors (TIMPs-2, -3, -4 and RECK) and its inductor (EMMPRIN) expression in CCOT. MATERIALS AND METHODS: We used 18 cases of CCOT submitted to immunolocalization of the target proteins and analysed in both neoplastic odontogenic epithelial and stromal compartments. RESULTS: All molecules evaluated were expressed in both compartments in CCOT. In epithelial layer, immunostaining for MMPs, TIMPs, RECK and EMMPRIN was found in basal, suprabasal spindle and stellate cells surrounding ghost cells and ghost cells themselves, except for MMP-9 and TIMP-2 which were only expressed by ghost cells. In stromal compartment, extracellular matrix, mesenchymal (MC) and endothelial cells (EC) were positive for MMP-2, -7, TIMP-3 and -4, while MMP-9, TIMP-2 and RECK were positive only in MC and MMP-14 only in EC. Statistical significance difference was found between both compartments for MMP-9 (P < 0.001), RECK (P = 0.004) and EMMPRIN (P < 0.001), being more expressed in epithelium than in stroma. Positive correlation between both stromal EMMPRIN and RECK expression was found (R = 0.661, P = 0.003). CONCLUSIONS: We concluded that these proteins/enzymes are differentially expressed in both epithelium and stroma of CCOT, suggesting an imbalance between MMPs and their inducer/inhibitors may contribute on the tumour behaviour.

Gestational protein restriction delays prostate morphogenesis in male rats.

Maternal malnutrition due to a low-protein diet is associated with functional disorders in adulthood, which may be related to embryonic development failures. The effects of gestational protein restriction on prostate morphogenesis in male offspring were investigated. Pregnant rat dams were divided into normoprotein (NP; fed a normal diet containing 17% protein) and hypoprotein (LP; fed a diet containing 6% protein) groups. On the day of birth (PND1), anogenital distance and bodyweight were measured in male pups. Seven males per experimental group (one male per litter) were killed, and the pelvic urethra was evaluated. LP offspring showed a significant reduction in bodyweight and anogenital distance on PND1. On three-dimensional reconstruction of the prostate, the number of prostatic buds was lower in LP than in NP males. Mesenchymal cells surrounding the buds were androgen-receptor positive, and the quantity and intensity of nucleus immunoreactivity was decreased in LP. The proliferation index was lower in LP than in NP prostatic buds. Immunoreactivity for α-actin in mesenchymal cells and that for epidermal growth factor receptor in epithelial cells was higher in NP than in LP. Our findings demonstrate that maternal protein restriction delays prostatic morphogenesis, probably because of considerable disruption in the epithelium-mesenchyme interaction.

Characterization and distribution of hyaluronan and the proteoglycans decorin, biglycan and perlecan in the developing embryonic mouse gonad.

The morphogenesis of tissues and organs requires dynamic changes in cells and in extracellular matrix components. It is known that various extracellular matrix molecules are of fundamental importance for gonad differentiation and growth. In the adult testis, the extracellular matrix represents an important component of the interstitium, participating in the transport of biologically active substances needed for the communication between different cellular components, as well as for the regulation of spermatogenesis and hormone production. The present study was designed in order to identify the proteoglycans biglycan, decorin and perlecan, as well as the glycosaminoglycan hyaluronan, during testis development in mouse embryos. Our data profile the chronology of testis differentiation, as well as the distribution of these extracellular matrix components during testis development in mice. We show that these extracellular matrix molecules are present early in the development of the gonads, suggesting that they play a role in gonad development. In addition, we found no decorin in the testicular cords. Furthermore, of the proteoglycans analysed, only biglycan was seen surrounding immature Sertoli cells and Leydig cell precursors in the testicular cords. This indicates that specific sets of extracellular matrix molecules are required in the various compartments of the developing gonad.

Fibroblast growth factor 9: cloning and immunolocalisation during tooth development in Didelphis albiventris.

There are no reports in literature about functional roles of fibroblast growth factor 9 (FGF-9) in tooth development in animals with complete tooth pattern. The classical model for studying tooth development is the mouse, which has small number of teeth and distinctive incisor and molar patterns. The opossum Didelphis albiventris with five upper and four lower incisors, one canine, three premolars, and four molars, on each side of the jaw, seems to be a convenient model to test results obtained in the mouse. Molecular expression studies indicate that FGF-9 participates in murine tooth initiation and regulation of morphogenesis. Searching for similarities and differences in FGF-9 expression between the opossum and the mouse, amino acid sequence and expression pattern of FGF-9 in the developing first molars of D. albiventris were characterised. FGF-9 cDNA sequence was obtained using RT-PCR and expressed in bacterial system for recombinant protein production and analysis of immunoreactivity. FGF-9 expression during tooth development was investigated by immunoperoxidase method. FGF-9 protein consists in a 209-residue polypeptide with a predicted molecular mass of 23.5 kDa. FGF-9 amino acid sequence has 98% of sequence identity to human and 97% to rodents. During tooth development, epithelial FGF-9 expression was seen at the dental lamina stage. Mesenchymal expression was seen at the bud stage and at the cap stage. No significant expression was found in the enamel knot. While in rodents FGF-9 is involved in initiation and regulation of tooth shape, it is suggested that it is only involved in tooth initiation in D. albiventris.