Electron Microscopy in Human Adult Wilms' Tumor
The p a p e r by S h e r w o o d et al. includes an ultrastructural element in an overall analysis of a case of h u m a n a d u l t W i l m s ' tumor. The overwhelming majority of the readership of this journal will p r i m a r i l y be interested in the cytogenetic aspects of this case and m a y not, therefore, appreciate the misinterpretation of the ultrastructural data w h i c h it is the aim of this letter to point out. In the text, the authors report ultrastructural features w h i c h they describe as characteristic of adult W i l m s ' tumor, p r i n c i p a l l y m a r k e d l y elongated m i t o c h o n d r i a and antophagic vacuoles. While m i t o c h o n d r i a with a distinctly elongated profile are not demonstrated in the electron micrograph figure, this illustration is reported to show, inter alia, autophagic vacuoles. The figure actually shows seven or so r o u n d e d structures with clear centers w h i c h I believe are s u b o p t i m a l l y preserved mitochondria. The two limiting membranes can just be discerned in one of these structures, as can (in other examples in the figure) remnants of cristae. Consequently, the study fails to show both the m a r k e d l y elongated m i t o c h o n d r i a and the autophagic vacuoles suggested as being characteristic of this tumor; rather, it shows r o u n d e d mitochondria, m i s i n t e r p r e t e d as autophagic vacuoles. Also, the description of some of the filaments as membrane bound w o u l d be inappropriate: this implies that they are enveloped in a m e m b r a n e - - w h i c h w o u l d be u n u s u a l - - r a t h e r than being attached to surface m e m b r a n e via a junction, w h i c h I feel is what may be intended. It is c o m m e n d a b l e that the authors should have sought data from a variety of technical d i s c i p l i n e s in order to arrive at an overall appreciation of the nature of the tumor in this case. However, the conclusions that can be drawn from the ultrastructural analysis w h i c h might lend support to the diagnosis are limited by an i n a d e q u a c y of interpretation. Despite the continuing emergence of new techniques, electron microscopy continues to play an important role in tumor diagnosis, but its success or effectiveness will be dictated by interpretational expertise. BRIAN EYDEN
Electron Microscope Unit Department of Histopathology Christie Hospital & Holt Radium Institute Manchester, United Kingdom
REFERENCES 1. Sherwood JB, Bard R, Bhargava M, Burns ER, Izbal MA (1989): A human adult Wilms' tumor'. Histologic, ultrastrnctural, and cytogenetic analysis. Cancer Genet Cytogenet 42:35-42.
Dr. Sherwood's Reply I very m u c h appreciate your sending me a copy of the Letter-to-the-Editor written by Dr. Brian Eyden entitled "Electron m i c r o s c o p y in h u m a n adult W i l m s ' tumor", referring to m y p a p e r entitled " A h u m a n adult Wilms' tumor." As Dr. Eyden stated in his letter, " . . . the authors . . . . sought data from a variety
267 © 1991 Elsevier Science P u b l i s h i n g Co., Inc. 655 A v e n u e of the Americas, New York, NY 10010
Cancer Genet Cytogenet 5 4 : 2 6 7 - 2 6 8 (1991) 0165-4608/91/$03.50
The p a p e r by S h e r w o o d et al. includes an ultrastructural element in an overall analysis of a case of h u m a n a d u l t W i l m s ' tumor. The overwhelming majority of the readership of this journal will p r i m a r i l y be interested in the cytogenetic aspects of this case and m a y not, therefore, appreciate the misinterpretation of the ultrastructural data w h i c h it is the aim of this letter to point out. In the text, the authors report ultrastructural features w h i c h they describe as characteristic of adult W i l m s ' tumor, p r i n c i p a l l y m a r k e d l y elongated m i t o c h o n d r i a and antophagic vacuoles. While m i t o c h o n d r i a with a distinctly elongated profile are not demonstrated in the electron micrograph figure, this illustration is reported to show, inter alia, autophagic vacuoles. The figure actually shows seven or so r o u n d e d structures with clear centers w h i c h I believe are s u b o p t i m a l l y preserved mitochondria. The two limiting membranes can just be discerned in one of these structures, as can (in other examples in the figure) remnants of cristae. Consequently, the study fails to show both the m a r k e d l y elongated m i t o c h o n d r i a and the autophagic vacuoles suggested as being characteristic of this tumor; rather, it shows r o u n d e d mitochondria, m i s i n t e r p r e t e d as autophagic vacuoles. Also, the description of some of the filaments as membrane bound w o u l d be inappropriate: this implies that they are enveloped in a m e m b r a n e - - w h i c h w o u l d be u n u s u a l - - r a t h e r than being attached to surface m e m b r a n e via a junction, w h i c h I feel is what may be intended. It is c o m m e n d a b l e that the authors should have sought data from a variety of technical d i s c i p l i n e s in order to arrive at an overall appreciation of the nature of the tumor in this case. However, the conclusions that can be drawn from the ultrastructural analysis w h i c h might lend support to the diagnosis are limited by an i n a d e q u a c y of interpretation. Despite the continuing emergence of new techniques, electron microscopy continues to play an important role in tumor diagnosis, but its success or effectiveness will be dictated by interpretational expertise. BRIAN EYDEN
Electron Microscope Unit Department of Histopathology Christie Hospital & Holt Radium Institute Manchester, United Kingdom
REFERENCES 1. Sherwood JB, Bard R, Bhargava M, Burns ER, Izbal MA (1989): A human adult Wilms' tumor'. Histologic, ultrastrnctural, and cytogenetic analysis. Cancer Genet Cytogenet 42:35-42.
Dr. Sherwood's Reply I very m u c h appreciate your sending me a copy of the Letter-to-the-Editor written by Dr. Brian Eyden entitled "Electron m i c r o s c o p y in h u m a n adult W i l m s ' tumor", referring to m y p a p e r entitled " A h u m a n adult Wilms' tumor." As Dr. Eyden stated in his letter, " . . . the authors . . . . sought data from a variety
267 © 1991 Elsevier Science P u b l i s h i n g Co., Inc. 655 A v e n u e of the Americas, New York, NY 10010
Cancer Genet Cytogenet 5 4 : 2 6 7 - 2 6 8 (1991) 0165-4608/91/$03.50
