tomoyotaketa0623@gmail.com
Keywords: sarcoidosis, solitary nodule, lung cancer
Abstract
Sarcoidosis shows various clinical and radiologic manifestations.
Nodular sarcoidosis is an uncommon form of pulmonary sarcoidosis. Cases
presenting as solid nodules are especially rare. We herein present a
case of nodular sarcoidosis with a solid nodule that was suspected to be
lung cancer.
A 67-year-old woman with no significant medical history was referred to
our hospital for the evaluation of an abnormal shadow on the chest
radiograph. The patient was a non-smoker. Physical examination revealed
no acute distress. Laboratory tests showed mildly elevated C-reactive
protein levels. Lung cancer tumor markers and angiotensin-converting
enzyme were within the normal range. Computed tomography (CT) showed a
solitary nodule with spicula in the S6 of the right
lung (Figure1). Positron emission tomography (PET)/CT scan showed mild
fluorodeoxyglucose uptake in the nodule and the right hilar lymph node
in the delay phase (Figure2). Transbronchial biopsy of specimens
demonstrated no malignant findings. We performed video-assisted
thoracoscopic lung surgery for the nodule in the right lower lobe, which
revealed noncaseating granulomas consistent with sarcoidosis (Figure3).
Acid-fast bacilli stain and tissue cultures were negative. Histologic
findings established a diagnosis of sarcoidosis.
Nodular sarcoidosis is an uncommon form of sarcoidosis prevalent in
2.4–4% of cases. 1) Most patients present with
multiple lung nodules, and solitary lung nodule is a rare radiologic
finding in about 18% of nodular sarcoidosis1). It is
difficult to differentiate between malignancy and nodular sarcoidosis
based on radiologic findings. Histological examination is necessary to
establish an accurate diagnosis.