A rare case of de novo mast cell leukemia manifested with duodenal ulcer perforation

Abstract

Introduction. Mast cell leukemia (MCL) is a very rare form of aggressive systemic mastocytosis, which has poor prognosis and limited treatment choice. Timely and proper MCL diagnosis plays an important role in treatment effectiveness, and remission achievement. It is known that mast cells are highly aggressive, easily degranulating with realizing a significant amount of histamine, that can lead to unusual manifestation of leukemia with primary injury of different extramedullary organs. There are no clear guidelines for MCL treatment, that is forcing doctors to seek new approaches for patient’s management. The aim is to present a case of de novo mast cell leukemia manifested with duodenal ulcer (DU) perforation and to analyze the effectiveness of mitoxantrone plus cytarabine combination as an initial treatment. Methods. A 62-year old man was diagnosed with de novo MCL, which manifested with DU perforation. The MCL diagnosis was made based on WHO (2016) diagnostic criteria. Patient underwent 2 courses of induction chemotherapy (ICT) with 3 days of 10 mg/m2 and 7 days of 200 mg/m2 cytarabine. Supportive treatment included surgery, antibiotics, double dose proton-pump inhibitors (pantoprazole), blood transfusions and standard infusion therapy. Patient’s general condition, hemogram, myelogram and endoscopy data were evaluated twice: at baseline and after 2 courses of CT. Results. Our patient was initially admitted to surgical department of Poltava Regional Clinical Hospital with acute abdominal pain, fever up to 380C, severe weight loss of 15 kg and signs of peritonitis. Patient had neither lymphadenopathy, nor hepatosplenomegaly. Upper endoscopy revealed an DU perforation. After its suturing and abdominal drainage, the antibiotics were prescribed. But in 3 days the fever continued, leukocytosis increased, immature cells appeared in the blood. The tests showed a HGB level of 95 g/l, RBC 2.99×1012/l, PLT 60×109/l, WBC 62×109/l, of which 45% immature cells with dense basophilic granules in the cytoplasm, sometimes with vacuolation. Bone marrow (BM) aspiration showed 31% of blast cells and 50% basophils, morphologically the same as in the blood. These cells were myeloperoxidase negative, nonspecific acid esterase positive. Acid phosphatase was positive, diffuse-granulated. Flow cytometry revealed a significant malignant cell population: 74,6% of BM cells were CD33-/+13-34-117+CD11c+CD11b+CD19-CD3-HLA-DR-, CD25+7+14-. After ICT the remission was achieved: general condition improved, complete DU healing according to endoscopy. In hemogram HGB level reached 137 g/l, RBC 4.99×1012/l, PLT 170×109/l, WBC 5.73×109/l, of which eos. 7%, bas. 0%, neutr. 51%, lymph. 35%, mon. 7%, no immature cells. BM aspiration showed normocellularity, blast cells 1%, basophils 4%. Conclusions. We have presented a case of a unique leukemia with rare manifestation. Mitoxantrone in combination with cytarabine could be an initial treatment choice in case of MCL with high amount of immature malignant cells.