Prepared by Daniel Gay, DO and Amolak Singh, MD, FACP from the Division of Nuclear Medicine, Department of Radiology, University of Missouri-Health Sciences Center, Columbia, MO.

CASE SUMMARY

A 71-year-old man was admitted for internal fixation of a fracture of the left hip (Figure 1). A chest radiograph revealed postobstructive pneumonia in the right upper lobe with right tracheal shift; a a computed tomographic (CT) scan of the chest was performed (Figure 2). Due to the possibility of lung cancer, a bone scan was ordered to exclude underlying osseous metastatic disease and pathological fracture (Figure 3). The patient was administered intravenous antibiotics for pneumonia and his left hip fracture was treated with hip replacement using Austin-Moor prosthesis. The laboratory data was unremarkable except for an elevated white cell count of 20.6 * 10 ³ /mm ³ (normal range 4.5 to 11.8 * 10 ³ /mm ³ ).

DIAGNOSIS

Increased ear uptake of Tc-99m diphosphonate, a normal variant on the bone scan

IMAGING FINDINGS

A bone scan was obtained following intravenous injection of 20 mCi of Tc-99m diphosphonate. The left hip pain was found to be related to a left hip fracture, which was evident on the plain film radiographs (Figure 1) and the bone scan (Figure 3). The bone scan was otherwise normal. A CT scan of the chest showed necrotizing pneumonitis with air fluid level suggesting abscess formation in the right upper lobe (Figure 2). The findings include right upper lobe atelectasis and collapse with mediastinal shift to the right apparently due to right endobronchial obstruction.

No malignancy was identified on the bone scan or other diagnostic workup. Incidentally, increased uptake in the ears was noted bilaterally (Figure 3). On examination, the ears were completely normal.

DISCUSSION

This case demonstrates a rare finding of Tc-99m diphosphonate uptake in normal ears. This uptake, presumably in the cartilaginous tissues was observed in the absence of clinical chondritis or soft-tissue ear inflammation. Similiar cartilaginous uptake has been reported previously in the nose, thyroid cartilage, periauricular areas, chest, and the small joints of the hands. ^1-4 These cases were related to polychondritis and/or cartilaginous calcification.

To describe the incidental findings of increased uptake in the normal ears, we have termed this finding a "Spock Ears sign," named for the character Spock from the Star Trek series.