Splenomegaly ضخامة الطحال
INSTRUCTION Examine this patient's abdomen. SALIENT FEATURES History · Fatigue (due to anaemia). · Night sweats, low-grade fever (due to hypermetabolic state caused by over-production of WBCs in chronic myeloid leukaemia, CML). · Abdominal fullness (due to splenomegaly). · Bleeding, bone pain (myeloproliferative disorders due to bone marrow infiltration). · History of leukaemia. · History of myelofibrosis. · History of residence in endemic areas of malaria, kala-azar. · Family history of Gaucher's disease. · History of fever (infectious mononucleosis, infective endocarditis). · Blurred vision, respiratory distress, priapism (due to leukostasis in CML). · Occasionally transverse myelitis (due to myelopoiesis in epidural space). Examination · Massive spleen. There may be associated anaemia. · Start low while examining for the spleen and be gentle during palpation. Even if you are certain it is the spleen, you must go through the motions of ruling out a palpable kidney: do a bimanual palpation and check for ballottement; feel for the splenic notch; auscultate for splenic rub. Proceed as follows: · Look for enlarged lymph nodes and anaemia. · Remember that the spleen must be at least two or three times its usual size before it can be felt. · Remember that, normally, the spleen does not extend beyond the anterior axillary line and lies along the 9th, 10th and 1 lth ribs. The spleen percussion sign is a useful diagnostic technique (Ann Intern Med 1967; 67: 1265). DIAGNOSIS This patient has massive splenomegaly (lesion), probably due to a myelo-proliferative disorder (aetiology). QUESTIONS What is your diagnosis? Myeloproliferative disorder: · Myelofibrosis, particularly in males. · Chronic myeloid leukaemia, particularly in females. How would you confirm your diagnosis? Bone marrow examination. ADVANCED-LEVEL QUESTIONS In which other conditions is a massive spleen palpable? · Malaria. · Kala-azar. · Gaucher's disease. In which conditions is a moderately enlarged spleen (two to four finger-breadths or 4-8 cm) felt? · Portal hypertension secondary to cirrhosis. · Lymphoproliferative disorders such as Hodgkin's disease and chronic lymphatic leukaemia. In which common conditions would the spleen be just palpable? · Lymphoproliferative disorders. · Portal hypertension secondary to cirrhosis. · Infectious hepatitis. · Glandular fever (infectious mononucleosis). · Subacute endocarditis. · Sarcoid, rheumatoid arthritis, collagen disease, idiopathic thrombocytopenia, congenital spherocytosis and polycythaemia rubra vera. · Slender young women (Ann Intern Mod 1967; 66: 301). What do you know about the genetics of chronic myelocytic leukaemia? The fusion of c-ab/ (normally present on chromosome 9) with bcr sequences on chromosome 22 is pathognomonic of the chronic phase of chronic myelocytic leukaemia (the Philadelphia chromosome). The p53 gene appears to be the culprit in cases of myeloid blast transformation and there are structural alterations of RB1or N-ras in less than 10% of the cases with myeloid blast crisis. What do you understand about the terms 'myeloid metaplasia' and extramedullary haematopoiesis'? 'Myeloid metaplasia' and 'extramedullary haematopoiesis' are used interchange-ably. They describe the process of ectopic haematopoietic activity that may occur in any organ system but predominantly affects the liver and spleen. It may or may not be associated with bone marrow fibrosis (myelofibrosis). The term 'myelofibrosis with myeloid metaplasia' is usually used to describe idiopathic myelofibrosis or agnogenic myeloid metaplasia (N Engl J Mod 2000; 342: 1255-65). What do you understand by the term 'chronic myeloid disorders'? Chronic myeloid disorders include: · Chronic myeloid leukaemia. · Myelodysplastic syndrome. · Atypical chronic myeloid disorder. · Chronic myeloproliferative disease: polycythaemia vera, essential thrombo-cythaemia, myelofibrosis with myeloid metaplasia. Essential thrombocythaemia in turn includes agnogenic myeloid metaplasia, post-polycythaemic myeloid metaplasia and post-thrombocythaemic myeloid metaplasia. What is the treatment of Gaucher's disease? Enzyme replacement therapy with glucocerebrosidase (alglucerase) is beneficial (N Engl J Mod 1991; 324: 1464-70; N Engl J Mod 1992; 327: 1632-6). P.C.E. Gaucher (1854-1918), Professor of Dermatology in France. Sir David Weatherall, FRS, contemporary Regius Professor of Medicine, Oxford, who has the unique distinction of being both a molecular biologist and an astute clinician. The 1902 Nobel Prize was awarded to Sir Donald Ross (1857-1932; born in Almora, India), University of Liverpool, for his work on malaria, in which he showed how it enters the organism and thereby laid the foundation for successful research on this disease and methods of combating it.