Solitary fibrous tumor: histological and immunohistochemical spectrum of benign and malignant variants presenting at different sites.

Department of Pathology and Cell Biology, Jefferson Medical College of Thomas Jefferson University, Philadelphia, PA 19107, USA.
Human Pathlogy (Impact Factor: 2.81). 05/1995; 26(4):440-9. DOI: 10.1016/0046-8177(95)90147-7
Source: PubMed

ABSTRACT Twenty-nine tumors (from 26 patients, including two with recurrent disease) diagnosed as solitary fibrous tumor (SFT) of the pleura (n = 23), mediastinum (n = 4), abdominal cavity (n = 1), and parotid gland (n = 1) were studied immunohistochemically. Three histologically malignant tumors showed areas of high cellularity and mitotic activity (more than 4 mitoses/10 high-power fields) with features resembling malignant fibrous histiocytoma, malignant hemangiopericytoma, or fibrosarcoma, together with areas typical of benign solitary fibrous tumor. Formaldehyde-fixed, paraffin-embedded tissues and avidin-biotin-complex immunostaining were used. All of the tumors showed vimentin positivity and did not stain for cytokeratin, glial fibrillary acidic protein, or muscle cell markers, except for focal desmin reactivity in seven tumors, mostly seen in frozen sections, and focal keratin reactivity in one histologically malignant tumor. The neoplastic cells were positive for CD34 and negative for CD31; these patterns also were seen in the three histologically malignant cases. In nine of the cases acetone-fixed frozen sections showed variable focal positivity for neurofilament proteins of 68 kd. We conclude that SFT is a neoplasm of fibroblasts/primitive mesenchymal cells with features of multidirectional differentiation. We also report the finding of a novel site for SFT, the parotid gland.

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    ABSTRACT: We review the morphofunctional characteristics of CD34+ stromal fibroblastic/fibrocytic cells (CD34+ SFCs) and report our observations. We consider the following aspects of CD34+ SFCs: A) The confusing terms applied to this cell type, often combining the prefix CD34 with numerous names, including fibroblasts, fibrocytes, dendrocytes, keratocytes, telocytes and stromal, dendritic, adventitial, supraadventitial, perivascular, paravascular and delimiting cells; B) Changes in their immunophenotype, e.g., loss of CD34 expression and gain of other markers, such as those defining mesenchymal and derivate cells (myofibroblasts, osteoblasts, chondroblasts, adipocytes); C) Morphology (elongated or triangular cell body and thin, moniliform, bipolar or multipolar cytoplasmic processes), immunohistochemistry (co-expression of and changes in molecular expression) and structure (characteristics of nucleus and cytoplasmic organelles, and points of contact and junctions in quiescent and activated stages by light and electron microscopy); D) Location and distribution in the vessels (adventitia or external layer), in the tissues (connective, adipose, blood, muscle and nervous) and in the organs and systems (skin, oral cavity and oropharynx, respiratory, digestive, urinary, male, female, endocrine and lymphoid systems, serosal and synovial membranes, heart, eye and meninges); E) Origin from the mesoderm and cranial neural crest in the embryo, and from stem cells (themselves or other cells) and/or peripheral blood pluripotent stem cells (circulating progenitor cells) in post-natal life; F) Functions, such as synthesis of different molecules, progenitor of mesenchymal cells, immunomodulation, parenchymal regulation (growth, maturation and differentiation of adjacent cells), induction of angiogenesis, scaffolding support of other cells and phagocytic properties. Since CD34+ SFCs are the main reservoir of tissue mesenchymal cells (great mesenchymal potential, probably higher than that proposed for pericytes and other stromal cells), we dedicate a broad section to explain their in vivo behaviour during proliferation and differentiation in different physiologic and pathologic conditions, in addition to their characteristics in the human tissues of origin (adult stem cell niches); G) Involvement in pathological processes, e.g., repair (regeneration and repair through granulation tissue), fibrosis, tumour stroma formation and possible CD34+ SFC-derived tumours (e.g., solitary fibrous tumour, dermatofibrosarcoma protuberans, giant cell fibroblastoma, nuchal-type fibroma, mammary and extramammary myofibroblastoma, spindle and pleomorphic cell lipoma, and elastofibroma) and H) Clinical and therapeutic implications.
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  • Neurology India 11/2012; 60(6):678-9. DOI:10.4103/0028-3886.105224 · 1.08 Impact Factor
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    ABSTRACT: Objectifs. - Identifier des critères tomodensitométriques évocateurs de malignité histologique à partir d’une étude rétrospective des tomodensitométries (TDM) préopératoires de tumeurs fibreuses solitaires de la plèvre (TFS) réséquées. Patients et méthodes. - Les TDM de patients opérés entre décembre 2004 et novembre 2012 ont été analysées rétrospectivement. Les caractéristiques tomodensitométriques ont été étudiées en aveugle du diagnostic histologique. Résultats. - 56 patients (33 femmes et 23 hommes, âge moyen : 60 ans) constituaient la population d’étude. La TFS était asymptomatique, découverte fortuitement dans 22 cas (45,8%). Sur l’examen anatomopathologique après exérèse (R0 dans tous les cas), 23 tumeurs (41%) étaient histologiquement malignes. Les critères significativement différents entre forme maligne et bénigne étaient : la taille (p=0,002) avec un seuil discriminant à 10 cm, l’hétérogénéité tumorale spontanée (p=0,02) ou après injection (p=0,03), l’existence de plages liquidiennes intratumorales (p=0,01), d’un épanchement pleural (p=0,01), de vaisseaux intratumoraux mesurables (p=0,02), d’un caractère hypervasculaire (vaisseaux intratumoraux visibles et/ou rehaussement intense) (p=0,001). La présence de calcifications intratumorales (p=0,2) et la densité maximale après injection (p=0,6) n’étaient pas significativement différentes. Conclusion. - Les arguments tomodensitométriques en faveur de la malignité histologique d’une TFS sont la taille supérieure ou égale à 10 cm, le caractère hypervasculaire, l’hétérogénéité tumorale, la présence d’un épanchement pleural. Mots-clés : Tumeur fibreuse solitaire ; TFS ; Plèvre ; Fibrome pleural ; Tomodensitométrie ; TDM ; Scanner.
    09/2013, Degree: MD, Supervisor: Marie-Pierre Revel (MD, PhD)