Fig 1.
(A) Hematoxylin and Eosin stained section from a tumor with initial diagnosis of ARMS, based on the monotonous morphology with round polygonal cells with hypercromatic nuclei (thin arrow), embedded in a collagenized stroma (320x, scale bar 70 μm).
(B) HE stained section from post-therapy specimen shows a reduction of cellularity with scattered cells displaying anaplastic features (thick arrow) with increased cell size (2-fold more than the adjacent cells) and nuclear hypercromasia. Atypical mitoses were seen in other areas (100x, scale bar 210 μm).
Fig 2.
(A) Immunostaining for Myf4 in histological sections of a t +ARMS, showing a positive nuclear staining (brown cells) in more than 90% of cells.
(B,C and D) Immunostaining for Myf4 in histological sections of a ERMS, immunostained for Myf4, varying from scattered cells (< 20%) to more than 40% and 70% of cells respectively (160x, scale bar 120 μm).
Table 1.
Immunohistochemical pattern (according to histotype).
Fig 3.
(A) Positive immunostaining for DAX-1 in histological section of a t+ ARMS.
(B,C) Negative immunostaining for DAX-1 in histological sections of two different ERMS. (D) Immunostaining for DAX-1 in histological section of a ERMS with the typically weak staining found in non-ARMS (80x, scale bars 240 μm).
Fig 4.
(A) Immunostaining for Ap2β in HE section of a t+ ARMS showing the typical alveolar pattern and wreath-like cells (thin arrow) (320x, scale bar 60 μm).
(C) Immunostaining for Ap2β in HE section of a t+ ARMS, showing a diffuse nuclear staining in more than 90% of cells, in keeping with the presence of translocation (160x, scale bar 120 μm). (B) Mixed RMS; HE staining show an alveolar pattern, with polygonal cells lacking the monotony of an ARMS (320x scale bar 60 μm). (D) Negative Ap2β staining in HE section of the same mixed RMS confirming the lack of translocation (80x, scale bar 240 μm).
Fig 5.
Pie charts showing the amounts of individual and co-expression of DAX-1 and Ap2β in ARMS t+ and non-ARMS.
(The arabic numbers indicate the number of positive tumors for each marker).
Fig 6.
Western Blot showing DAX-1 expression in 4 out of five cell lines.
The asterisk indicates a non-specific band present only in RMS cell lines. The histogram shows the relative amounts of DAX-1 expression in each cell line. The densitometry was calculated (ImageJ software) as the ratio between the intensities of the bands corresponding to DAX-1 for each cell line and the corresponding bands of β-tubulin multiplied by 100 and expressed in arbitrary units (AU).