Haematology - Lymphadenopathy and Lymphoma Flashcards
Ddx generalized lymphadenopathy
- Lymphoma: Low-grade cause wax-and-wane LN, High-grade cause rapidly growing masses
- Lymphoid Leukaemia, eg. CLL, ALL (less common in AML/CML)
- Infections: Viral, eg. IM, CMV, HIV, EBV Bacterial, eg. TB, brucellosis, syphilis, Typhoid fever Protozoal, eg. toxoplasmosis Fungal: Cryptococcus
- Connective tissue disease, eg. RA, SLE
- Infiltration, eg. sarcoidosis, amyloidosis
- Drugs, eg. phenytoin**, hydralazine
Ddx Localized lymphadenopathy
Localized lymphadenopathy
- Local infection
- Metastasis from solid tumors
- Lymphoma, esp Hodgkin’s lymphoma
Describe lymphadenopathy
- Sites
- Size cut-off
- Consistencies
- Fixation
- Overlying skin changes
Site:
- Localized in local infection and early lymphoma
- Generalized in late lymphoma
Size:
- Large (>1cm) usually abnormal
Consistency:
- Hard: carcinoma deposits
- Soft: may be normal
- Rubbery: may be due to lymphoma
Tenderness: indicates infection or acute inflammation
Fixation:
- Fixed: more likely to be infiltrated by carcinoma
Overlying skin:
- Inflammation indicates infection
- Tethering indicates carcinoma
List all lymph node groups and their drainage sites in body
Causes of submental and submandibular lymphadenopathy
Causes of Jugular, Posterior cervical and suboccipital lymphadenopathy
Causes of pre- and post-auricular Lymphadenopathy
Causes of supraclavicular and axillary lymphadenopathy
Causes of epitrochlear lymphadenopathy
Causes of Inguinal lymphadenopathy
History taking for lymphadenopathy
History:
LN itself: rapidly enlarging, tender (reactive) vs painless, rubbery/hard (malignant)
Localizing symptoms to suggest infection, malignancy
Constitutional symptoms, eg. fever, weight loss, night sweats
Relevant infective exposure, eg. cats, insect bite, travelling, venereal exposure, IVDU
Medications, eg. phenytoin
Physical exam for LN
Nature of LN: site, size (>1cm abnormal) consistency (hard vs rubbery vs soft), fixation (mobile vs fixed vs matted), tenderness (indicates rapid enlargement with capsule stretching)
Inspect and palpate drainage basin, eg. oral cavity, thyroid, parotid, external auditory meatus…
Other relevant signs, eg. hepatosplenoegaly, tonsils (also part of lymphoid system), abdominal mass, SVCO (if any)
Ddx lymphadenopathy based on consistency
Hard: solid malignancy, previous infl’n with fibrosis
Firm, rubbery: lymphoma, chronic leukaemia
Soft: acute leukemia, reactive
First-line investigations for lymphadenopathy
CBC/D, viral studies, serology
Imaging (CXR, USG, CT, MRI)
Biopsy:
- Fine-needle aspiration cytology (FNAC): cytological information only, useful in infection and solid organ malignancies (USELESS in lymphoma)
- Core-needle biopsy or incisional biopsy: provides histological information, useful for lymphoma
- Excisional biopsy: architectural details required for diagnosis of lymphoma
Ddx atypical lymphocytosis/ infectious mono- like syndrome
Viral infections: EBV, CMV, HIV, acute viral hepatitis
Bacterial: atypical organisms e.g. Mycoplasma pneumoniae, Legionella penumophila, Salmonella, Rickettsia
Mycobacterial: Disseminated TB
Dimorphic fungi: Talaromyces marneffei
Parasitic: Toxoplasma gondii
Drug reaction/ hypersensitivity
Acute lymphoblastic leukemia
Investigations for atypical lymphocytosis
PBS - atypical lymphocytes
Microbiology workup:
- Blood culture
- Sputum culture and AFB smear
Specific bacterial tests:
- Mycoplasma serology
- Urine for RAT against Legionella Antigen
- Widal’s test (salmonella)
Specific viral tests:
- CMV IgG and IgM and pp65
- Monospot test and EBV serology test (EBV DNA)
- HIV antibody test
Parasite:
- Toxoplasma serology test
Ddx mediastinal mass
- Lymph node enlargement: Lymphoma, Metastatic LN
- Thymoma
- Germ cell tumor
- Retrosternal goiter
- Dilated aortic arch (e.g. syphilis)
- Neurofibroma