Splenomegaly
Schistosomiasis
This is prevalent in Africa (particularly
around the Nile delta), Asia and South America. It is caused by infection with Schistosoma
mansoni in nearly 75 per cent of cases and by Schistosoma haematobium in
the remainder. Splenic enlargement is produced by hyperplasia which is induced
by phagocytosis of disintegrated worms, ova and toxins, and by portal
hypertension which is the result of hepatic fibrosis.
Clinical
features
Splenomegaly arising from schistosomiasis can
occur at any age and is more prevalent in males. The degree of splenic
enlargement reflects the extent of hepatic fibrosis and may be massive.
Investigations
The urine and faeces are examined for ova.
Liver function tests reveal a varying degree of hepatic impairment. A
hypochromic
anaemia is always present.
Treatment
Successful medical treatment of established
cases does not result in regression of the splenomegaly. Removal of the painful
and bulky spleen is indicated where there is no evidence of hepatic or renal
insufficiency. If ascites is present, a portosystemic shunt should be combined
with splenectomy.
Tropical
splenomegaly
Massive enlargement of the spleen occurs
frequently in the tropics, for example in malaria (especially in children), kalaazar
and schistosomiasis (see above). In parts of Africa and New Guinea splenomegaly
cannot be fully attributed to these diseases because tropical splenomegaly is
restricted to only a few adults in areas where malaria is endemic. The most
likely explanation is an abnormal immune response to malaria or unusual species
of plasmodia. Malnutrition may also be a factor and there is a high incidence in
lactating women.
The
spleen is grossly enlarged (2000—4000 g). This is associated with anaemia due
to shortened red cell life and thrombocytopenia due to splenic sequestration of
platelets, which respond to splenectomy. Splenectomy is indicated for those
disabled by anaemia or by the weight of an enormous spleen. Splenectomy reduces
immunity to malaria and therefore antimalarial chemotherapy (e.g. proguanil)
should follow splenectomy in malaria endemic areas and be maintained for life.
Hypersplenism
due to portal hypertension
Splenomegaly invariably accompanies portal
hypertension. This splenic enlargement results in thrombocytopenia (due to
splenic sequestration of platelets) and granulocytopenia. These are permanently
relieved when splenectomy accompanies operation for the relief of portal
hypertension. Shunt surgery alone does not have the same effect.
Felty’s
syndrome
A moderate number of patients with chronic
rheumatoid arthritis develops mild leucopenia; in a few of these, neutropenia
becomes extreme and is usually associated with enlargement of the spleen; this
combination is referred to as ‘Felty’s syndrome’. A remarkable
characteristic of this syndrome is that the leucopenia and splenic enlargement
are apparently unrelated to the severity of the arthritic changes; indeed, in
some instances the arthritis has begun to improve or has become quiescent by the
time the low white cell count and the splenomegaly become unmistakable. In those
cases in which the arthritis is slight but the splenic enlargement and blood
changes are much in evidence, a diagnosis of primary splenic neutropenia is
sometimes made. The results of splenectomy are variable. Usually there is an
improvement in the blood picture with increased neutrophils, but this improvement is not maintained. However, the
liability to infections seems to be decreased in many cases and rheumatoid
arthritis that has become resistant to steroid therapy may, once again, react
favourably to the administration of steroids.
Tuberculosis
Tuberculosis of the spleen is not so uncommon
as is sometimes believed. It occurs chiefly in adults between 20 and 40 years
of age. When a patient has splenomegaly with asthenia, loss of weight and an
evening fever, it
is well to bear
in mind the possibility that the enlargement of the spleen may be due to
tuberculosis. Too often the signs lead to erroneous diagnosis of leukaemia or
some other disorder for which splenectomy is not indicated. Occasionally tuberculosis
of the spleen produces portal hypertension. Another form is cold abscess, which
is very rare. Splenic puncture followed by culture or guinea-pig inoculation
will yield positive results. A therapeutic test with antituberculous drugs
(Chapter 8) brings about some improvement, and there is less danger of
dissemination of the tubercle bacilli if splenectomy is undertaken. The
operation, which is usually rendered difficult because of adhesions, is
contraindicated only if other active tuberculous lesions are found to be
present. Otherwise, the results of splenectomy in the treatment of
tuberculosis
of the spleen are excellent.
Neoplasms
The most common benign tumour of the spleen is
the haemangioma which may, on occasion, develop into a haemangiosarcoma.
Splenectomy may be necessary. The commonest cause of neoplastic enlargement of
the spleen is lymphoma. Splenectomy may play a part in the management of these
conditions (Chapter 17), but the role is now limited.
Porphyria
Porphyria is a hereditary error of catabolism
of haemoglobin in which porphyrinuria occurs. The abdominal crises, which are
characterised by violent intestinal colic with constipation, are liable to be
precipitated by the administration of barbiturates, for which these patients
have an idiosyncrasy. The patient is anaemic, frequently suffers from
photosensitivity
and, in advanced stages of the disease, neurological or mental symptoms (from
damage to the brain) are commonly present. On examination, the spleen will be
found to be enlarged. On a number of occasions the splenic enlargement, which is
usually well marked, has been overlooked and the abdomen has been opened on the
presumptive diagnosis of intestinal or appendicular colic, with negative
findings. Another manifestation of acute porphyria is spasmodic abdominal pain
followed by jaundice.
Two
methods of establishing the diagnosis are available.
•
The urine is sometimes normal in colour —
usually it
is orange
(often dismissed as ‘concentrated’). If a urine
specimen
is left exposed to daylight for a few hours it develops
a port wine colour, particularly near the surface where it
is exposed to the
air. There are several conclusive laboratory tests for porphyrinuria.
•
Radiography of the abdomen —
serial
radiographs show areas of intestinal spasm causing short segments of gaseous
dilatation of the small and large intestine, and especially of the caecum.
Treatment
Often there is a striking decrease in the serum
sodium level and the patient is improved considerably by the infusion of
isotonic saline solution with careful control of electrolyte balance. Methadone
is the best drug to relieve the abdominal pain. If a sedative is required, one
of the phenothiazines (e.g. chlorpromazine) should be given. Splenectomy is not
of value except in the uncommon erythropoeitic type with splenomegaly.
Gaucher’s
disease
As mentioned, the spleen may take an active
part in the storage of abnormal lipoids, as does the remainder of the
reticuloendothelial system. In the case of Gaucher’s disease the lipoid in
question is glucocerebroside. Gaucher’s disease, which is rare, is
characterised by enormous enlargement of the spleen, which may weigh 8 or 9 lbs
(3.6—4.1 kg). In most cases the splenic enlargement begins in early childhood,
often before the age of 12 years, although the patient rarely seeks advice
before adult life. Until the splenic enlargement becomes massive the symptoms
are few. There is anaemia, a yellowish-brown discoloration of the skin of the
hands and face, and a curious conjunctival thickening (pinguecula) that helps to
clinch the clinical diagnosis. Slavonic and Jewish races appear to be more prone
to the disease than other races. The diagnosis is confirmed by finding
Gaucher’s cells in the bone marrow.
Treatment
Splenectomy rids the patient of a large
abdominal swelling, but the operation is difficult because of perisplenitis and
friability of the splenic pulp. It does not greatly influence the course of the
disease, but because it reduces
the hypersplenism (anaemia, leucopenia and thrombocytopenia) and makes the
patient more comfortable, the procedure may be indicated.
Leukaemia
Leukaemia is one of the conditions to be
considered in the differential diagnosis of splenomegaly. The diagnosis can be
made by examination of a blood or marrow film. The main treatment is
chemotherapy or radiotherapy; occasionally marrow transplantation may be necessary.
Splenectomy during the chronic phase of chronic granulocytic leukaemia will not
reduce the incidence of blastic transformation or improve survival. The
procedure should be reserved for hypersplenism occurring during the chronic
phase, or for when bone marrow transplantation might be necessary. In rare
instances the removal of a symptomatic enlarged spleen during the blastic phase
produces relief, but the period of relief is brief and the operation hazardous.
Splenectomy
is occasionally indicated for palliation of a painful bulky spleen in chronic
lymphocytic leukaemia, but only after consultation with an experienced
haematologist.
Abscess of the
spleen
If a splenic embolus is infected, and the
primary condition does not prove fatal, a splenic abscess may be expected to
follow Other sources of metastatic abscess of the spleen are typhoid and
paratyphoid fever, osteomyelitis, otitis media and puerperal sepsis. An abscess
in the right upper pole of the spleen may rupture and form a left
subdiaphragmatic abscess. If the abscess is in the lower pole, rupture results
in diffuse peritonitis.
Treatment
As a rule, owing to dense adhesions, drainage
of the abscess is the only course. Very rarely, splenectomy may be possible with
the abscess in situ. The drainage may
be performed percutaneously, under ultrasonic or CT guidance, so avoiding the
need for operative intervention.