Clinicobiological features and prognostic impact of diffuse large B-cell lymphoma component in the outcome of patients with previously untreated follicular lymphoma.

BACKGROUND: The co-existence at diagnosis of follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL) components (FL/DLBCL) has been considered a transformed lymphoma and accordingly treated although clinicobiological information on these patients is scarce. The aim of this study was to analyze the initial features and outcome of FL/DLBCL patients in the rituximab era. PATIENTS AND METHODS: All patients consecutively diagnosed at a single institution with FL/DLBCL (n = 40), as well as those with pure FL (n = 328) or de novo DLBCL (n = 510) as controls. RESULTS: The proportion of the DLBCL component was highly variable (median 50%). In 29 FL/DLBCL cases analyzed, the cell of origin was GCB in 86%, ABC in 10% and unclassifiable in 4%. NOTCH1-2 was mutated in 10% of these cases. The proportion of DLBCL component did not impact on overall survival (OS). Regarding initial characteristics, patients with FL/DLBCL were closer to FL in terms of primary nodal origin, good performance status and advanced stage, whereas the other features were intermediate between FL and DLBCL. FL/DLBCL patients were treated as DLBCL with no further intensification. Complete response and primary refractory rates were 65% and 20%, respectively, with these figures being similar to DLBCL and worse than FL. Progression-free survival and OS were intermediate between FL and DLBCL (5-year OS: 85%, 73% and 63% for FL, FL/DLBCL and DLBCL, respectively). FL/DLBCL histology did not reach independent prognostic value for OS in the multivariate analyses. CONCLUSIONS: The outcome of FL/DLBCL patients is not worse than that of de novo DLBCL. These cases should be treated with immunochemotherapy as DLBCL, but intensification with ASCT may not be necessary. The biological insights of FL/DLBCL warrants further genetic and molecular studies.

[Single fibrous tumor of the parapharyngeal space]. / Tumor fibroso solitario del espacio parafaríngeo.

A solitary fibrous tumor (SFT) of the parapharyngeal space presented with local symptoms (hearing loss, nasal obstruction, and paralysis of the soft palate and tongue). SFT, originally described as a mesothelial tumor of the pleura, now is recognized as a mesenchymal tumor that occurs in different locations. In the head and neck region, about 50 cases have been reported. This is the fifth published report of an SFT of the parapharyngeal space. The diagnosis was confirmed by immunohistochemical (positivity for vimentin, CD34, and CD99) and ultrastructural markers (fibroblastic characteristics).

Tumor fibroso solitario del espacio parafaríngeo / Solitary fibrous tumor of the parapharyngeal space

Se presenta un caso de tumorfibroso solitario (TFS) de localización parafaríngea, con un cuadro clínico de afectación locorregional (hipoacusia, obstrucción nasal y parálisis velopalatina y de hemilengua). Se señala que el TFS, descrito inicialmente a nivel pleural y de origen mesotelial, hoy día se reconoce en otras múltiples localizaciones con un origen mesenquimal. En la región de cabeza y cuello se han descrito unos 50 casos y el presente es el quinto caso publicado a nivel parafaríngeo, habiéndose confirmado el diagnóstico mediante marcadores inmunohistoquímicos (vimentina, CD34 y CD99 positivos) y ultraestructurales (hábito fibroblástico) (AU)

A solitary fibrous tumor (SFT) of the parapharyngeal space presented with local symptoms (hearing loss, nasal obstruction, and paralysis of the soft palate and tongue). SFT, originally described as a mesothelial tumor of the pleura, now is recognized as a mesenchymal tumor that occurs in different locations. In the head and neck region, about 50 cases have been reported. This is the fifth published report of an SFT of the parapharyngeal space. The diagnosis was confirmed by immunohistochemical (positivity for vimentin, CD34, and CD99) and ultrastructural markers (fibroblastic characteristics) (AU)

Development of the tendon of Todaro during the human embryonic and fetal periods.

This study covers the development of Todaro's tendon during human embryonic and fetal periods. The tendon primordium first appears when human embryos attain a CR length of 22 mm, but it only becomes well-defined at 24 mm CR length. The tissue that will form the tendon proceeds exclusively from the inferior endocardial cushion. The tendon establishes a close relationship with the base of the septum secundum during its path towards the right venous valve, carrying myocardial tissue out and forming the fasciculus limbicus inferior to muscular tissue. The tendon's relationship with the superior aspect of the atrioventricular node primordium during the first part of its path is of particular interest. The relationship is most intriguing when the node morphology is least defined. This would explain the possible embryogenesis of extra atrioventricular nodes. We also consider Todaro's tendon to be largely responsible for the development of the sinus band which protrudes as a crest inside the right atrium. This band is particularly well-developed in the fetal heart and provides an explanation for the large sub-Eustachian sinus cavity.

[The development of the atrioventricular node and bundle of His in the human embryonic period]. / Desarrollo del nodo atrioventricular y del haz de His en el período embrionario humano.

To study the development of the atrioventricular specific system, together with the closely related mesenchymal tissue (from which the fibrous skeleton of the heart later develops). Thirty human embryos ranging from 3 mm to 30 mm crown-rump length (Carnegie stages 10-23) were used. The primordium of the atrioventricular specific system was observed for the first time in human embryos of 10 mm Crown-Rump length (Carnegie stage 16) as a cellular aggregate located below the inferior endocardial cushion. The primordium cells originate from the myocardium of the posterior wall of the atrioventricular canal. The primordium later forms both the atrioventricular node and the His bundle. The mesenchymal tissue which surrounds these features originates from the endocardial cushions (particularly from the inferior endocardial cushion). Todaro's tendon and the central fibrous body are later formed from the inferior endocardial cushion. The atrioventricular node and His bundle are both formed from the primordium of the atrioventricular specific system. The node is produced from the cranial-dorsal extension of the primordium while the His bundle is produced from the growth of the primordium in a ventral-caudal direction. The central fibrous body is anatomically defined in the stages post-dating morphogenesis of the atrioventricular specific system.

Study of the development of the atrioventricular conduction system as a consequence of observing an extra atrioventricular node in the normal heart of a human fetus.

We have observed an extra atrioventricular node in the normal heart of a human fetus. It is located in the septal wall of the right atrium, subendocardially, and just where Todaro's tendon leaves this wall to go toward the inferior vena cava valve. In its trajectory, this tendon gives way to a remarkable prominence in the cavity of the right atrium: the sinus band. In order to explain the embryogenesis of this extra atrioventricular node, we have studied the normal development of the atrioventricular specific system and have concluded that the atrioventricular node is formed from a growth and displacement toward the atrium of the primitive atrioventricular specific material, which originates from the myocardium of the posterior wall of the atrioventricular canal. Likewise, during its development, the atrioventricular node keeps in close proximity with the Todaro's tendon. In our view, this accounts for the embryogenesis of the extra atrioventricular node, since a fragment of the atrioventricular node can remain cranial to Todaro's tendon and be displaced by it in a craniodorsal direction. This fragment would then lead to the formation of an extra atrioventricular node like the one present in the heart of the fetus we have examined.