Facial weakness
harry206 - 05-05-09 02:16

A healthy 32 year-old Puerto Rican man comes to the physician because of facial weakness. He woke up this morning and noticed some numbness in his right cheek. While he was brushing his teeth, he observed that his mouth was deviated to the left. Two weeks ago, he developed some painful nodes in both legs. He thought they were "allergic bumps," and did not come to the physician because the pain decreased in severity and the lesions improved. He has no other medical problems. His family history is not significant. He is a taxi driver, and works 14 to 16 hours daily. He has smoked one pack of cigarettes daily for the past 15 years. He drinks one bottle of beer every other day, and smokes marijuana occasionally. He is currently not taking any medications. His vital signs are within normal limits. Examination reveals a right facial droop. His nasolabial fold is deviated to the left. Only the right frontal creases disappear on grimacing. The liver is palpated 2 cm under the right costal border. There are two indurated, erythematous, tender nodules and multiple brown-red, non-tender, smaller nodules over the extensor surfaces of both legs.

The patient received a short course of corticosteroid therapy for the facial paralysis, which significantly improved thereafter. Laboratory tests were ordered during the previous visit. The results are the following:

CBC

Hb
12.6 g/dL

Ht
38%

MCV
90fl

Platelet count
280,000/cmm

Leukocyte count
9,000/cmm

Segmented neutrophils
70%

Lymphocytes
24%

Monocytes
6%



Serum chemistry

Serum Na
138 mEq/L

Serum K
4.0 mEq/L

Chloride
103 mEq/L

Bicarbonate
24 mEq/L

BUN
18 mg/dL

Serum creatinine
0.9 mg/dL

Calcium
11.0 mg/dL

Blood glucose
84 mg/dL



LFT

Total bilirubin
1.3 mg/dL

Direct bilirubin
0.8 mg/dL

Alkaline phosphatase
350 U/L

Aspartate aminotransferase
47 U/L

Alanine aminotransferase
50 U/L



The chest x-ray showed mediastinal widening and bilateral interstitial infiltrates. PPD test was negative. Which of the following is the most appropriate procedure to confirm the diagnosis?