A 15-yr old girl with lymphadenopathy

[K06100]

A 15-year-old girl presents to her pediatrician with a complaint of dull upper abdominal pain and a sore throat, both lasting for about 1 week. She has no major medical history and reports that she is not sexually active. Her temperature
is 38.1°C (100.6°F), blood pressure is 118/80 mm Hg, pulse is 65/min, and respiratory rate is 12/min. Her spleen is enlarged, and she has significant cervical and periauricular lymphadenopathy.
Which of the following is the most appropriate diagnostic test?

(A) CT of the abdomen
(B) Exploratory laparotomy
(C) Fine-needle aspiration of a lymph node
(D) Flow cytometry on peripheral lymphocytes
(E) Latex agglutination assay

[Hitman]

ans >........E...............

[Ayman Qasrawi]

Latex agglutination (Monospot test) for mononucleosis

[K06100]

Correct Answer is E........

[step_enhancer]

Originally Posted by K06100

Correct Answer is E........

Can u explain ??

[K06100]

The correct answer is E. This patient presents with a history and physical examination findings classic for infectious mononucleosis caused by the Epstein-Barr virus (EBV). EBV may remain in saliva for months after the disease is contracted, and a high percentage (25%–50%) of patients exposed to EBV may carry the virus without experiencing clinically significant disease. The “monospot” test used in most clinics is a latex agglutination assay, and is both sensitive and specifi c. Treatment is essentially supportive, using acetaminophen and nonsteroidal anti-infl ammatory drugs to
treat fever and pain. Patients with splenomegaly should avoid contact sports due to the risk of splenic rupture.
Answer A is incorrect. The patient’s history and examination point to mononucleosis as a cause of her splenomegaly and dull abdominal pain. If her latex agglutination assay was negative and her pain increased in severity or persisted
without explanation, an imaging study would be reasonable.
Answer B is incorrect. Infectious mononucleosis is a common and plausible fi t for this patient’s presentation. Opening her abdomen in search of the cause of her dull upper abdominal pain would be hasty, and without an imaging study in this non-emergent case, would probably constitute malpractice.
Answer C is incorrect. Fine-needle aspiration is a relatively noninvasive technique for diagnosing diseased tissue, most often malignancies. It would be overly aggressive in this patient whose clinical picture is more consistent with an acute infection than with a developing cancer.
Answer D is incorrect. Flow cytometry is useful in diagnosing diseases in which specifi c cell identity needs to be determined, e.g., lymphomas, leukemias, and various other malignancies. It has no role in the diagnosis of mononucleosis,
and would be a long way down the road in this patient with a plausible (and inexpensively-diagnosed) etiology.