Male patient, 13 years old, derived by volume increase in the right shoulder region.
On physical examination, masses on the inner thigh and on the face of the upper rib, plus a mid-posterior mediastinal tumor, diagnosed by chest X-ray, were also described.
The hemogram showed no pathological characteristics.
A soft tissue ultrasound study reported multiple masses in the subdermal region located in different parts of the body.
A tumour biopsy was performed, which described an undifferentiated neoplasm composed of large cells of pleomorphic nuclei growing discohesively on a densely vascular network.
Immunohistochemistry was performed for CDla, CD3, CD4, CD15, CD20, CD25 (clon: 4C9), CD31, CD34, CD45 (clon: PD7/9926 and CD56
Search results were positive.
Biopsy was reported as histological and immunohistochemical findings consistent with myeloid sarcoma.
1.
The study of bone marrow by myelogram and biopsy ruled out tumor involvement, only changes described were described.
The immunophenotype was normal and PCR (polymerase chain reaction) in bone marrow and peripheral blood samples were negative for translocations (9;22), (8;21), (15;17v), (9;16).
Conventional cytogenetic analysis was performed (according to standard protocol for bone marrow samples in Marrow-max® medium culture, hypotonia with KC10.075M and fixation with an acetic acid-methanol® sample with only one chromosome).
FISH study in bone marrow for ETO/AML1 translocation was negative in 100 nuclei studied, and no ETO signal loss was observed, which ruled out the possibility of a monosomy 8.
To better characterize the tumor, we decided to perform the FISH study in the formalin-fixed and paraffin-embedded tumor tissue sample. No fresh tissue was available to attempt a primary tumor culture.
We began the evaluation of the sample for translocation (8;21), described in the literature as the most frequent manifestation in pediatric patients1, followed by inv (16) and finally MLL(llq23).
The first two were reported to be normal in 100 nuclei studied, while in the study of signal partitioning for MLL on chromosome 11, 50% of the nuclei with three signs were detected, with no evidence of consistent partitioning 11,2%.
