15) Cysts & Tumours of the Spleen скачать в хорошем качестве

15) Cysts & Tumours of the Spleen

Cysts- are unusual in the spleen. Classified in to 2 groups –(a) Parasitic, (b) Non –Parasitic cysts. (a)Parasitic cysts –due to echinococcal disease. -this type account for 70% of splenic cysts, where hydatid disease is endemic. (Australia, South America & Greece) (b)Non –parastic cysts – -often encountered in countries where echinococcal disease is rare. Classified in to 2 groups – i)Primary or true cysts- have epithelial lining . -can be of dermoid, epidermoid & epithelial varieties. ii) Pseudo cysts- Mor common & result from liquefaction of old haematoma. -areas of infarction & inflammation. Clinical features – -due to merence of mass & compression of adjacent viscera & due to diaphragmatic irritation. Rx- Usually splenectomy. For selected non –parasitic cysts may be treated by aspiration. In very large cysts Intra operative drainage may facilitate splenectomy. Tumours - -primary tumours are rare in the spleen . -Majority of the primary tumours are malignant – either sarcoma, angiosarcoma or splenic lymphoma. Metastatic tumours – rare in the spleen. -Though spleen is an effective filter & frequently show malignant cells yet metastatic deposits are rare. -It is probably due to splenic immune mechanism. -Only in case of hodgkin’s disease & Non –Hodgkin’s lymphomas that metastasis in the spleen is noticed. Hypersplenism (Increased splenic function with peripheral cytopenias & a reactive bone marrow.) 4-criteria have been laid down for diagnosis are - i)Anaemia, leucopenia, thrombocytopenia or combinations there of. ii)Compensatory bone marrow hyperplasia, iii)Splenomegaly & iv)improvement following splenectomy. -Platelets & granulocytes are most frequently & severely affected. Classified into 2 groups – a) Primary hypersplenism - -where an underlying disease can not be identified to account for the exaggerated splenic function. b) Secondary hyper splenism-an underlying disease is identified. Non –Hodgkin’s Lymphomas-(NHL) -The constitute a group of primary malignancies of lympho-reticular tissue. -this groups is divided into 4 major histologic types – 1)Lymphocyte predominant, 2)Nodular sclerosis, 3)Mixed cellularity, 4)Lymphocyte depletion. Yet for prognostic & therapeutic purpose NHL is classified in to- a) Nodular (favourable) and b) diffuse(unfavourable) varieties. Clinical features- -In 25%of patients the onset of NHL occurs in extranodal site. -Fever weight loss and night sweats are frequently prevent. Rx-Chemo therary & radiation therapy Type of Rx is based on the histopathologic type of lymphoma & the stage of the disease. Splenectomy in this condition is considered for 3 reasons – 1) To improve haematologic depression, 2) To relieve symptomatic splenomegaly, 3) To prevent from recurrent splenic infarction. -Preoperative –splenectomy –require red cell and platlet transactions. -In about 80 % - 90 % of patients significant therapeutic benefit may be achieved by splenectomy. -the prognosis is more favourable for the nodular than for the diffuse forms of NHL. SPLENECTOMY Indications –as described above (on previous page)- 1)Blood disorders, etc. Pre-operative management- -Performed for haematologic disorders, -Blood transfuion but avoids in ITP (Idiopatic thrombocytopenic) disease, platelet packs are not administered preoperatively as these platelets are destroyed by the spleen and hence become ineffective. -However platelet sould be kept in hand to be used after removal of spleen. -Nasogastric tube – to decompress the stomach. (To facilitate handling of the short gastric veins within the gastrospleenic ligament. Techinique of operation – Incision –Midline (lt.) sub costal incision for elechive splenectomy (Lt.) paramedian. Mobilization of the spleen- Division of gastrosplenic ligament- Division of splenic vessels - Post –operative course- Increasd leucocytes & platelets counts are observed. Post operative complications- 1)Haemorrhage, 2) (lt.) lower lobeatectasis (associated with pleural effusion), 3) Gastric dilatation, 4) Haematemesis (due to mucosal damage) of the stomach, 5)Damage of the tail of the pancreas (during dissection of hilar vessels). 6)Thrombosis- (venous - DVT), 7) Gastric fistula (due to compromise in vascular supply) 8)Infection –Frequently isolated from septic splenectomised children are -those of diplococcus pheumonia & H-influenzae. -other bacteria to cause septicaemia in splenectomised children. -so it is the practice to give pneumococcal antitoxin & antibiotic cover until 18 yrs of age. -Polyvalent pneumococcal vaccine should be gien (Pneumonova 0.5 ml). -Particularly those undergoing splenectomy which will be followed by chemotherapy & radiation. -Also should reeive antimalarial prophylaxis.