Spleen - Pathology

()Map\Tab LYMPHORETICULAR & HAEMATOPOIETIC SYSTEM (Map/Tab) SECONDARY LYMPHOID SYSTEM

NB:Be aware of age-related changes regarding the spleen

Anatomy & Physiology

See here

Splenic Lesions

splenomegaly is the main clinical finding associated with the spleen in disease

Splenitis

Anthrax

Torsion

Haemolytic Anaemia

Chronic Venous Congestion

this may be seen along with chronic venous congestion of the liver in cases of chronic cardiac failure

Barbituates

administration of barbituates can produce a degree of splenomegaly due to splenic engorgement by erythrocytes

Splenic Tumours

these are important surgically since splenomegaly can be diagnoses clinically by palpation or X-ray and some are surgically curable

Hyperplastic Nodules or Benign Lymphoma

very common incidental findings in older dogs
should not be mistakenly identified as pathognomic lesions
consist of nodules of hyperplastic white and red pulp

- usually 1-2 cms in size, but occasionally may be larger

- spherical

- protrude hemispherically from the surface as yellow and red mottled nodules

infrequently, may rupture and give rise to haemorrhage

Haemangioma

benign tumour of dogs
may grow to considerable size

- the size of the lesion giving rise to clinical signs is compounded by haemorrhage from and into the tumour

- thus, a large mass of apple size may be found protruding from the spleen and adherent to the omentum

on section, it is largely blood clot
responds well to surgery

- therefore it must be distinguished from haemangiosarcoma

Haemangiosarcoma

highly malignant tumour of dogs
distinguished from the superficially similar haemangioma by the presence of much more formed, solid tumour tissue
accurate prognosis demands histological examination
secondaries are common locally in the omentum and in the liver

- course is usually short, often only a month or two

- metastases may occur in almost every organ

Haematopoietic Neoplasms

lymphosarcoma

splenomegaly occurs in multicentric lymphosarcoma
splenic enlargement may be marked if any form of lymphosarcoma is in leukaemic phase