Extramedullary haematopoietic tumour of the breast: a case report in a woman with secondary myelofibrosis following essential thrombocythaemia

Abstract

Sir: We thank Dr Tan for pointing out that more than one gene can lo-localize to a particular band in a chromosome. We agree that in the variant chromosomal aberration inv(2)(p23q35) in anaplastic large cell lymphoma, ATIC at the 2q35 locus is involved. However, it is also well known that the t(2;13) (q35;q14) translocation in alveolar rhabdomyosarcoma involves PAX3 on chromosome 2q35. [1][2][3] In our paper we were speculating as to why alveolar rhabdomyosarcomas should also stain with ALK protein by immunohistochemistry. We were not attempting to implicate particular genes in a definite manner, but as PAX3 is close to ATIC and the former is involved in alveolar rhabdomyosarcoma it may be the reason why ALK immunostaining is found. We did follow by saying 'A similar chromosomal abnormality may be found in rhabdomyosarcoma and account for ALK protein expression'.Whilst Dr Tan is correct in what he says, perhaps he should pursue this issue with the authors of reference 5 from our paper. 1 1. Shapiro DN, Sublett JE, Li B et al. Fusion of PAX3 to a member of the forkhead family of transcription factors in human alveolar rhabdomyosarcoma.