Download unexplained enlarged lymph nodes

St. Richard’s Hospital
SPECIALTY: HAEMATOLOGY
CLINICAL PROBLEM: UNEXPLAINED
ENLARGED LYMPH NODES
ASSESSMENT AND INVESTIGATION OF UNEXPLAINED LYMPHADENOPATHY
Although normal lymph nodes are usually impalpable, careful examination by an
experienced clinician can reveal palpable small nodes in almost all individuals,
especially in the tonsillar and inguinal regions. As a rule lymph nodes need to be
>0.5cms before they are considered to be significant.
MAIN CAUSES OF LYMPHADENOPATHY
Viral Infection
Infectious mononucleosis, EBV,
CMV, HIV
Pyogenic Infection
Local or Systemic
Granulomatous:
Infectious
Tuberculosis, Syphilis,
Toxoplasmosis, Histoplasmosis,
etc.
Non-infectious
Sarcoidosis
Immunologically-based
Rheumatoid arthritis, SLE,
Dermatopathic, Drugs
Malignant
Lymphoma, Leukaemia,
Carcinoma, Melanoma, Sarcoma
Congenital
Lymphangiomas, Cystic Hygroma
Lymphadenopathy is most commonly due to infection. Lymphomas and
leukaemias are relatively rare and malignant involvement of a lymph node is
most commonly due to metastatic carcinoma.
CLINICAL MANAGEMENT
In many instances the cause of lymphadenopathy will be apparent after taking a
careful history and performing a thorough clinical examination.
History
This should include the patient’s general health, past illnesses, exposure to
infection, including contact with animals or birds and travel abroad, and systemic
symptoms such as fever, weight loss, sweats and pruritus.
Physical examination
Location and extent of the lymphadenopathy and characteristics of the nodes
themselves. Localised, tender lymphadenopathy should prompt a search for an
infected lesion or portal of entry in the area drained by the node.
Tender nodes are usually inflammatory or reactive, but rapid enlargement due
to malignancy can stretch the capsule and produce pain.
Hard nodes, especially when fixed and matted together, suggest malignancy.
INITIAL INVESTIGATIONS
These should include a full blood count, ESR and examination of the blood film.
These may be diagnostic in cases of leukaemia and lymphoma, or may point to a
viral cause such as infectious mononucleosis. Additional investigations might
include a Monospot test, antibody screens for an infective cause and a chest
radiograph.
LYMPH NODE BIOPSY
The cause of lymphadenopathy can be determined in the majority of cases by
history, clinical examination and the simple investigations outlined above. If this
fails to yield a diagnosis a lymph node biopsy may be necessary, but knowing just
when to do this is often difficult and the usefulness of this investigation is reduced if
it is performed indiscriminately.
If the clinical suspicion of lymphoma is strong and there are good reasons
why treatment should not be delayed, especially if the patient’s condition is
deteriorating, a biopsy should be taken as soon as possible. If the suspicion is
less strong, then one should wait at least until the results of all the investigations are
back before deciding on a biopsy. This may give sufficient time for a number of
conditions to resolve spontaneously.
The diagnostic yield is improved by the careful selection of the node to be biopsied.
Nodes in sites other than the tonsillar and inguinal sites are preferred as the latter
are frequently involved in reaction to local trauma and infection. Sometimes,
enlarged nodes peripheral to a malignant node may show only a reactive pattern
and it is better to remove the largest node, even if this is technically more difficult.
LYMPH NODE BIOPSY (continued)
Close liaison with the histopathologists and haematologists is essential as a
number of techniques can be applied to the fresh, unfixed biopsy material in
addition to conventional histopathology, i.e. immunocytochemistry,
chromosomal analysis and molecular studies.
Conventional histological examination remains the cornerstone of diagnosis
in a lymph node biopsy. Needle core biopsy, and more recently, fine needle
aspiration have been advocated as a more convenient and rapid replacement to
formal excisional biopsy. They are often useful in a diagnosis of metastatic
carcinomas. However, whenever there is a clinical suspicion of lymphoma one must
recommend removal of an entire node, in one piece, as the best means of obtaining
an accurate diagnosis.
Immunocytochemistry techniques are routinely applied to lymph node biopsies
and can readily identify the different cell types within lymphoid tissue and can
accurately classify the immunological origin of most lymphoproliferative disorders.
They can also differentiate anaplastic tumours such as carcinoma, lymphoma,
melanoma and sarcomas.
Molecular studies
These techniques, although not routinely applied, can help in diagnosis.
Establishing a malignant as opposed to the reactive nature of a lymph node is
difficult in a small proportion of patients. This is particularly true in T cell
malignancies, which lack any readily identifiable markers of monoclonality and in
which analysis of the T cell receptor gene can provide objective evidence of
monoclonal expansion.
Author: Dr. Philip Bevan, Consultant Haematologist, Western Sussex Hospials
NHS Trust St. Richard’s Hospital, Chichester.
Others involved: All LRMG Committee Members
Published: 12/99 Reviewed: 04/02, 09/07, 03/10
Next Review: 03/12