Mumps:

Mumps is a viral illness associated with non-specific infectious symptoms including fever, headaches, mylagias, fatigue, and parotitis (swelling and pain of the parotid gland-responsible for producing saliva). However, some may be relatively asymptomatic, while others can develop downstream complications like meningitis, encephalitis, orchitis, and deafness.

While both Canada and the U.S. have active vaccination programs in children, sporadic outbreaks have been occurring in recent years. In particular, the CDC reported over 5000 cases in 2016 in the U.S as compared to 229 in 2012. There is currently an active outbreak in Halifax.

The reasons behind such spikes  are likely multifactorial and relate to:

1. Variable effectiveness of the mumps vaccine
2. Lack of previous exposure to wild-type virus
3. The intensity of the exposure. This final point is exhibited by the fact that many outbreaks tend to occur in close-quarters settings like college dormitories and among professional athletes (Sidney Crosby and other NHL players in 2014). The Brandon Wheat Kings hockey team  in the WHL had an outbreak this month.

Lumps & Bumps:

While mumps is one type of infection that causes true “swollen glands”, enlarged lymph nodes are far more common and are not actually glands. Lymph nodes are a component of the immune system which houses cells responsible for staving off infections.

Lymphadenopathy refers to swelling of lymph nodes which can be either painful or painless. There are a myriad of causes associated with the development of lymphadenopathy (see table below):

The differential diagnosis can be further subdivided based on loco-regional nodal enlargement patterns:

Based on these myriad etiologies, a comprehensive clinical assessment is necessary and should include review of:

• PMHx: Autoimmune or connective tissue disease, lymphoma/leukemia, HIV
• MEDs: Immunosupression or prior exposure to chemotherapy/immunodmodulating agents (increased risk of lymphoproliferative disorders), drugs associated with serum-sickness like reaction
• SHx: Sexual history, HIV and TB RFs, Travel history (especially to regions in the U.S. with endemic fungal exposure risk)
  • Histoplasmosis-Ohio River Valley and lower Mississippi River
  • Coccidiomycosis-Southwest U.S (Arizona, California, Nevada, New Mexico)
• HPI: B symptoms, head-to-toe review of symptoms for infectious and autoimmune disease
• Physical examination: general exam, vital signs, all nodal groups, liver, spleen, joints, rheum screen, skin
  • Don’t forget tonsils (lymphatic tissue!)

A large panel of investigations to evaluate lymphadenopathy may include some/all of the following, depending on features found on history and examination:

• CBC, Film, Coags
• Lytes, Xlytes, Alb
• LFTs, LDH, Uric Acid
• Group and Screen
• Renal Function, Urea
• Peripheral blood flow cytometry
• HIV, Bartonella, VDRL, HBV, HCV, monospot and EBV serology, CMV serology, toxoplasma and lyme serology, HIV, histoplasmosis urine antigen, coccidiomycosis IgG and IgM
• serum ACE, ESR, CRP, ANA, ENA, anti-DS-DNA, C3,C4, Urinalysis, Urine ACr, C-ANCA, P-ANCA
• Blood and Fungal Cultures
• CXR
• CT Head and Neck + CAP
• When a tissue sample is required (and often is), the preferred modality is surgical excision because needle-aspirate biopsies may be associated with high rates of false negative results when lymphoma is present (only part of LN may have lymphoma cells which could be missed).

A hallmark pathologic finding for Hodgkin lymphoma from an excised LN is the presence of Reed-Sternberg cells which demonstrate a morphologic feature termed “Owl’s eye nuclei” (see below image).

Staging of lymphoma is less complex than most solid organ malignancies and is guided by the Ann-Arbor Staging System.

The most widely used chemotherapy regimen for Hodgkin Lymphoma is referred to by an acronym: ABVD. Radiation therapy may also be provided. Long-term risks of treatment include cardiotoxicity (radiation and chemo-related), pulmonary toxicity (chemo-related), infertility, secondary malignancies, and hypothyroidism.

Final Points:

• Non-Hodgkin Lymphomas are classified by whether they are B or T-cell diseases, and on the basis of their natural history (see below table)
  • Indolent: Follicular, Mantle Cell
  • Aggressive: DLBCL (1st line chemoTx regimen: R-CHOP)
  • Very Aggressive: Burkitt’s

• A word on Richter transformation
  • Patients with a history of CLL can, for mechanisms not yet well-elucidated, convert to DLBCL
  • Involves conversion from chronic, indolent disease to an aggressive lymphoma
  • When to suspect:
    • Sudden clinical deterioration marked by:
      • Rapid increased LAN/splenomegaly
      • Worsening B symptoms
      • Acute rise in LDH
      • Acute fall in Hb
      • Acute fall in Plt

Further Reading & Resources:

1. CDC info re: Mumps
2. Public Health of Canada info re: Mumps
3. Gaddey, HL and Riegel, AM. Unexplained lymphadenopathy: Evaluation and differential diagnosis. Am Fam Physician 2016 Dec 1; 94(11): 896-903.
4. American Society of Hematology (ASH) Image Bank (for pathology and blood film findings-FREE resources)