An 18-years-old male patient, unmarried, with no known co-morbids, presented in ER with complaints of urinary hesitancy and burning micturition for 3 days. General physical examination revealed abdominal distention with palpable spleen and priapism, rest of the systemic examinations were unremarkable. Patient was vitally stable and well oriented to time, place and person. CBC reported Hb of 7.6 g/dl, WBC count of 457.6 x 10^9/L and Platelet count of 111 x 10^9/L, so there was hyperleucocytosis and bicytopenia. Differential count showed 48% neutrophils, 6% lymphocytes, 5% metamyelocytes, 29% myelocytes, 5% basophils, 4% eosniophils, 2% monocytes 1% blasts and 6 NRBCs per 100 WBCs. Basophilia was present with absolute count of 22.9 x 10^9/L. The presenting complain of priapism was attributed to hyperviscosity secondary to hyperleucocytosis. Ultrasound abdomen showed mildly enlarged liver with size of 16.9 cm having normal parenchymal echotexture. Spleen was bulky and enlarged having span of 17.1 cm. Ultrasound testes revealed right-sided epididymitis with reactionary minimal septated hydrocele and scrotal wall thickening. Ultrasound KUB (Kidney Ureter Bladder) was unremarkable. Serum electrolytes were normal. Urology team was taken on board, they catheterized the patient and symptomatic management was given. As the CBC and peripheral smear findings were suggestive of chronic myeloproliferative process, PCR was done to look for and if present, quantify BCR/ABL1 gene fusion transcripts, and it reported 50.55% positivity, thus the patient was diagnosed as CML. Karyotype was performed to screen for additional chromosomal abnormalities and it showed presence of Philadelphia chromosome as the single anomaly. His LDH was markedly raised (1428 U/L), uric acid was marginally increased (9.0 mg/dl) while LFTs, urea and creatinine were normal. Bone marrow biopsy was then performed for the confirmation of phase of disease. Aspirate showed myeloid hyperplasia (myeloid to erythroid ratio was 8:1) and 2% blasts. Trephine revealed hyper cellular marrow with 95-100% cellularity, exhibiting myeloid hyperplasia, prominent dwarf-sized megakaryocytes with no evidence of focus of blasts. Hence the case was concluded as chronic phase CML as per the WHO Classification 2022 criteria.

Patient was prescribed 1^st line TKI (Imatinib) PO 400 mg OD, along with iron supplement (PO FeSO4 200 mg BD) and Allopurinol PO 300 mg OD. Three months later, PCR for BCR/ABL quantification was repeated to assess treatment response and it reported 16.64% positivity, after which the dose of Imatinib was increased to 600 mg OD, as the optimum response which is less than 10% BCR/ABL transcripts could not be achieved. During this time period, patient was asymptomatic. Follow up CBCs reported progressive improvement in hemoglobin and decline in WBC count. However, platelets initially recovered but again showed a fall in count. Patient was continued with the same medicines. PCR quantification after a further 3 months reported 0.65% positivity, consistent with optimum response. Patient remained asymptomatic. Repeat PCR after a further 6 months (i.e., 1 year after treatment initiation) reported 0.66% positive, thus the major molecular response (MMR) could not be achieved. Patient is being continued with the same treatment, so far, he has been asymptomatic with no treatment related side effects. Platelet count also increased and is now normal. His latest CBC reported Hb of 12.6 g/dl, WBC count of 6.20 x 10^9/L and platelet count of 217 x 10^9/L.