Introduction: Chloroma (synonyms: Chloromyeloma, granulocytic leukosarcoma, granulocytic sarcoma, myeloblastic sarcoma, myelosarcoma) is a rare disease that presents as an extramedullary tumour of myeloid cells. Most patients subsequently develop acute myeloid leukemia (AML), and their prognosis is poor. Here, we report the case of a 73-year-old man with Chloroma of the gastrointestinal tract. This case is noteworthy because GI tract infiltration with leukemic cells is very rare, and it is even more rare as an occurrence preceding the development of systemic leukemia.
Methods: A 73-years-old patient with myelodysplastic syndrome (-5q-syndrome) had been treated with lenalidomid and in the later course with azacicitine. He had constant low platelet counts and required frequent transfusions of red blood cells. The patient now presented with abdominal pain and signs of intermittend intestinal obstruction. Colonoscopy two years earlier was normal. A CT scan was performed showing a large obstructing tumour at the ileocecal valve. Colonoscopy revealed a round tumour with 6cm in diameter in the ascending colon involving the ileum (Figures A and B). Virtual chromoendoscopy using narrow band imaging did not show any adenoma like signs. Histopathologic assessment and immunohistochemical examination showed acute monocytic/myeloblastic leukemia (chloroma of the Ileocecal valve), in which blasts are positive for chloracetate esterase but negative for CD 34 (Figures C – F). In monocytic and myeloblastic leukemia absence of CD-34-positive myeloblastic cells in the periphery is not contradictory to the diagnosis but rather a frequent observation.
Conclusion: In our patient transformation to acute myeloid leukemia had occurred, although myelodysplastic -5-syndome is regarded as low risk group for this event. Treatment with corticosteroids ameliorated the symptoms in our patient, however overall prognosis is dismal. This case report demonstrates that manifestation of acute leukemia can occur primarily in the periphery, in this case as an intestinal destructive tumour. Chloroma may be considered to be a variant of AML. The lesion was first described by Burns in 1811 and the term „chloroma“ was introduced by King in 1853 because of its green colour.
