IM Board Review

A young woman with enlarged lymph nodes

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A previously healthy 25-year-old woman presents to her primary care physician with a “lump in the neck”—a painless, swollen area under the lower part of her left jaw that she noticed several weeks ago and that continues to enlarge. She has also noted a recent increase in fatigue, as well as the onset of generalized headaches and mild sinus congestion. Presumed by another physician to have sinusitis, she had already received a 2-week course of an antibiotic (she could not recall which antibiotic), with no improvement in her symptoms. She has been trying to lose weight and has lost 5 pounds in the last 4 months. She reports no fevers, chills, or night sweats.

She works as a special-education teacher and lives in a rural area. She has not travelled during the past year, inside or outside the United States. When she was an adolescent, she underwent tonsillectomy and had her wisdom teeth extracted. Her family has no history of hematologic dyscrasia or malignancy. She has two dogs, which are indoor pets, and she utilizes a city water supply.

1. Which of the following causes of a lump in the neck is most important to exclude?

  • Viral or bacterial infection
  • Lymphoma
  • Oral cavity abscess
  • Infectious mononucleosis
  • Congenital anomaly

A lump in the neck can be broadly categorized as congenital, inflammatory, or malignant. Congenital causes include branchial cleft cyst (anterior to the sternocleidomastoid muscle) and thyroglossal duct cyst (usually in the midline between the hyoid bone and the isthmus of the thyroid gland). Other possibilities include lipoma and, less frequently, a salivary gland disorder such as sialadenitis.

A complaint of a neck lump very often correlates with the physical finding of lymphadenopathy, and a standard approach in evaluation should be undertaken, based on the mnemonic “PAAA”—ie, palpation, age, area, and associated symptoms.

Palpation. In palpation of the lymph node group, one should note the size and tactile quality of the lymph nodes and assess for abnormal temperature, tenderness, fluctuance, and mobility. In general, lymph nodes larger than 1.5 cm by 1.5 cm are more likely to be of granulomatous or neoplastic origin.1 Nodes that are tender, warm, or fluctuant are likely reactive to a local infectious process; nodes that are firm, matted, and fixed are most characteristic of malignancy; and rubbery, mobile nodes may represent either granulomatous disease or lymphoma.2

Age helps stratify the risk of malignancy as an underlying cause, which is increased in people over age 50 presenting with lymphadenopathy.1

Area. An assessment of the extent of the lymphadenopathy can guide the search either for a cause of generalized lymphadenopathy or for pathology in the anatomic area drained by the particular lymph node group, including the scalp (occipital or preauricular); external ear (posterior auricular); oral cavity (submandibular, submental); soft tissues of the face and neck (superficial cervical); upper respiratory tract and thyroid (deep cervical); and thoracic cavity and abdominal cavity (supraclavicular).

Asking the patient about occupational, environmental, and behavioral risk factors and associated signs and symptoms such as fever, rash, diaphoresis, unintentional weight loss, and splenomegaly helps to narrow the differential diagnosis. Common diagnoses to consider in the evaluation of peripheral lymphadenopathy are listed in Table 1.

A viral or bacterial upper respiratory infection is one of the most common causes of cervical lymphadenopathy, although this usually does not persist for many weeks. Mononucleosis more commonly involves the posterior cervical chain and is often accompanied by splenomegaly. Because of the prolonged presence of the lump, malignancy, including lymphoma, is the most important of the answer choices to consider and rule out in a timely fashion.


The woman appears to be well and is in no acute distress. Her oral temperature is 98.1°F (36.7°C), blood pressure 119/72 mm Hg, heart rate 86 beats per minute, and respiratory rate 18 breaths per minute.

The head and neck appear normal. The nares are patent with normal mucosa and no visible drainage. There is no tenderness during palpation of the facial sinuses. The ear canals, tympanic membranes, oropharynx, and tongue appear normal. Several firm, mobile, nontender lymph nodes about 1 cm in diameter are palpable in the left submandibular and right supraclavicular area. No other occipital, submental, axillary, or inguinal lymphadenopathy is noted. There is no overlying erythema or warmth. The cardiac examination is normal, and the lungs are clear on auscultation. The abdomen is soft, nontender, and nondistended, with no organomegaly. The skin appears normal, and the neurologic examination is normal.


Results of initial laboratory tests are as follows:

  • White blood cell count 5.74 × 109/L (reference range 3.70–11.00)
  • Red blood cell count 4.49 × 109/L (3.90–5.20)
  • Hemoglobin 13.0 g/dL (11.5–15.5)
  • Hematocrit 38.4% (36.0–46.0)
  • Platelet count 210 × 109/L (150–400)
  • Mean corpuscular volume 85 fL (80–100)
  • Absolute neutrophil count 3.26 × 109/L (1.45–7.50)
  • Blood urea nitrogen 8 mg/dL (8–25)
  • Creatinine 0.65 mg/dL (0.70–1.40)
  • Lactate dehydrogenase 146 U/L (100–220)
  • Uric acid 4.0 mg/dL (2.0–7.0)
  • Thyrotropin (thyroid-stimulating hormone) 1.86 μIU/mL (0.4–5.5).

A recent tuberculin skin test obtained as part of her employment screening was negative, and so was a test for antibody to human immunodeficiency virus (HIV), obtained recently before donating plasma. A urine pregnancy test done in the office was also negative. A peripheral blood smear showed slight toxic granulation with rare reactive lymphocytes.

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