Relapse of AML five year after allogeneic stemcelltransplantation as a Granulocytic Sarcoma

Chloroma is a rare extramedullary neoplasm composed of immature myeloid cells (myeloid sarcoma) (1) presenting as singleor multiple masses (2). They affect bothsexes equally(2), children more commonly than adults and60% of the patients are younger than 15 years old(3).Myeloid sarcomas are associated with AML in 2-8% of the cases, especially in situationsof cytogenetic abnormalities such as t(8;22), inv(16) and 11q23(4,5,6).The testicles are considered to be an uncommon site for myeloid sarcomas(7,8) and there are a few cases with localization of Chloroma in one of the testises (9). We report an extremely rare case of Chloroma of the testis in patient with past history of AML. Case report: A 32-year-old man, with a history of AML M4 from 6 years ago presented to clinic because of a painless right testicular mass. He received aggressive chemotherapy with multiple episodes of relapse and eventually underwent allogeneic peripheral blood stem cell transplantation 5 years ago. The testicular mass was detected 45 months after transplantation. Right testicular ultrasound showed two masses, 1.7 × 1.1cm and 2.2× 1.5.Then right orchiectomy was performed. Histopathologic examination showed diffuse infiltration of immature monotonous large cells with scanty cytoplasm and round-to-oval nuclei. Immunohistochemical studies consistently manifested the expression of LCA, BCL2, CD117, CD68 (Focally) and Ki67 Index about 60%. (figure2,3,4,5,6), but negative for CK,PLAP,CD10,CD3,CD20,CD3O,CD34 and ALK1,and the diagnosis of granulocytic sarcoma was established. Discussion Chloroma usually occurs as a secondary manifestation either before or simultaneously with AML. The sites most affected are bone structures (cranium, paranasal sinuses, sternum, ribs, vertebrae and pelvis), central nervous system, soft tissues of the head and neck (especially the orbit), skin, lymph nodes and breast (16, 17). Initial presentation of AML with involvement of the testicles, as described in the present case, is considered to be uncommon, with a poor prognosis (8, 18). The correct histological diagnosis is based on identifying the granulocytic characteristics in the neoplastic cells. Because of high morphological variability and possible nonidentification of myeloid differentiation (variable), errors may occur especially when the neoplastic cells shows minimal myeloid differentiation such that it is composed of poorly differentiated cells distinct from the myeloblasts that are found in the bone marrow in cases of concomitant AML(5,19).In conclusion, despite the rarity of myeloid sarcoma, it should be taken into consideration in the differential diagnoses of undifferentiated neoplasia.

کلیدواژه ها:

AML ، testis ، Granulocytic Sarcoma