chronic myelomonocytic leukaemia ( cmmol ) is a rare disease with an incidence of 0.370.72 per 100 000 population . the median age at diagnosis varies between 65 years and 75 years [ 14 ] .
the radical treatment is allogeneic stem cell transplantation , although this treatment is unsuitable for most patients because of their advanced age [ 6 , 7 ] .
the median survival of patients with cmmol is 1520 months [ 5 , 6 , 8 ] .
several case reports have indicated that excess surgical stress causes an acute blastic crisis , which contributes to a poor outcome [ 9 , 10 ] .
a 68-year - old man complained of having a reduced appetite for approximately 5 months and weight loss during the previous 4 months . on 12 may 2012
, he visited a nearby general internal medicine clinic for the evaluation of left lower quadrant abdominal pain .
he was referred to the department of internal medicine at asahi general hospital ( asahi , japan ) for investigation and treatment .
he began taking oral hydroxyurea ( hydrea ; bristol - myers squibb , princeton , nj , usa ) .
he was unable to stop the gingival bleeding that had been ongoing for 5 hours .
he then visited the emergency department of asahi general hospital and was referred to the department of dentistry and oral surgery . at the initial visit
the right molar teeth ( 47 and 48 ) showed grade iii mobility , and their gingivae were painful with continuous bleeding .
1a ) . the right molar teeth ( 46 and 47 ) showed class iii alveolar ridge deficiency on panoramic radiographs and were mobile teeth ( fig .
we packed an absorbable haemostat ( surgicel ; ethicon , somerville , nj , usa ) into the gingivae and sutured 30 silk threads above it . finally , we used surgical dressing packs ( coe - pak ; g.c .
figure 1:(a ) the oral photograph at the initial visit , immediately after the gauze with the astringent has been removed .
( b ) the oral photograph after the extraction of teeth 47 and 48 . 

( a ) the oral photograph at the initial visit , immediately after the gauze with the astringent has been removed .
the internal medicine department assigned a clinical diagnosis of cmmol , based on the blood and bone marrow examinations conducted on 13 june 2012 .
computed tomography on june 25 indicated that bone absorption had nearly reached the right inferior alveolar canal , and a ring of sequestrum was present under tooth 47 ( fig .
we diagnosed right mandibular osteomyelitis , based on these clinical features . on 11 july 2012 ,
the patient was hospitalized in the department of haematology ward because of significant anaemia and decreased platelet numbers . on the same day ,
the internal medicine specialist placed him on intravenous  piperacillin  tazobactam ( zosyn ; pfizer , new york , ny , usa ) .
he afterwards complained of severe pain in the socket ( 47 and 48 ) , despite receiving the potent opioid analgesic dihydrohydroxycodeinone ( fentanyl ; daiichi - sankyo , chiyoda - ku , tokyo , japan ) .
hence , we decided to apply a surgical anti - inflammatory treatment in consideration of an acute blastic crisis .
a bone marrow examination on july 13 showed no signs of acute blastic crisis of his cmmol .
after we consulted an internal medicine specialist , we planned a surgical procedure to clean the inflamed region in his mouth . on the day before the surgery
, he was administered a transfusion of platelet concentrate ( 20 units ) and piperacillin  tazobactam to prevent bleeding and further infection . on july 20 , with the patient under local anaesthesia , we surgically resected the right lower sequestrum and extracted molar 37 , which displayed severe caries .
the blood examination indicated improvement in the platelet count after the transfusion . after performing an inferior alveolar block
, we removed the necrotic bone with ultrasonic bone surgery ( variosurg ; nsk , ashikaga , tochigi , japan ) until there was bleeding from the bone surface ( fig .
we placed gauze with tetracycline ointment in the socket and sutured 30 silk thread to compress it ( fig .
( b ) we removed necrotic bone with ultrasonic bone surgery until there was bleeding from the bone surface .
( b ) we removed necrotic bone with ultrasonic bone surgery until there was bleeding from the bone surface .
( d ) we used 30 silk thread sutures to compress the gauze . on august 11
the formation of granulation tissue had nearly covered the surface of the bone , and all oral discomfort had disappeared ( fig .
we later placed a bridge in the upper anterior teeth and added a partial denture ( fig .
we placed a bridge for upper anterior teeth 12 , 11 , 22 and 23 , and a partial denture .
we placed a bridge for upper anterior teeth 12 , 11 , 22 and 23 , and a partial denture . on 3 january 2013
, he admitted himself to the hospital in the haematology ward because of exertional dyspnoea .
the internal medicine specialists diagnosed cmmol that was undergoing acute leukaemic transformation by bone marrow examination .
he died on 10 february 2013 because of cardiac arrest , following haemorrhagic shock and cardiovascular failure due to cmmol .
in all patients with cmmol , every effort must be made to use the least invasive procedure possible . in the present patient ,
our deepest concerns were to have a proper balance between invasiveness and healing , and to avoid evoking an acute blastic crisis [ 9 , 10 ] .
our most important goal was to alleviate the patient 's discomfort by using a minimally invasive procedure to eliminate infection . based on haematology results ,
the oral surgery did not trigger the acute blastic crisis of cmmol in this patient .
the surgery was necessary to improve his oral environment and to prevent further infection and more pain . because cmmol is associated with a risk of acute blastic crisis and a poor prognosis , any surgical procedure in these patients must be considered on a case - by - case basis .
 we report a case of chronic myelomonocytic leukaemia ( cmmol ) in a 68-year - old man who developed osteomyelitis of the mandible . at the initial visit 
 , he reported uncontrolled gingival bleeding , despite self - administered haemostasis . 
 he complained of severe pain in the socket , despite potent opioid analgesia . 
 after consultation with the internal medicine specialists , we undertook a surgical anti - inflammatory approach that included sequestrectomy with massive blood transfusion . 
 his physical condition was ameliorated after the surgical procedure , and he was discharged from the hospital . 
 however , 3 months later , he died because of cardiac arrest after haemorrhagic shock and cardiovascular failure because his cmmol had developed to an acute blastic crisis . 
 this experience demonstrates that the most important goal in such cases is to alleviate a patient 's discomfort by applying minimally invasive actions to eliminate infection and improve the quality of life without causing deterioration in the cmmol status . 
Introduction
Case Report
Discussion
Conflict of Interest Statement