Radioiodine uptake in inactive pulmonary tuberculosis

Radioiodine may accumulate at sites of inflammation or infection. We have seen such accumulation in six thyroid cancer patients with a history of previously treated pulmonary tuberculosis. We also review the causes of false-positive radioiodine uptake in lung infection/inflammation. Eight foci of radioiodine uptake were seen on six iodine-123 diagnostic scans. In three foci, the uptake was focal and indistinguishable from thyroid cancer pulmonary metastases from thyroid cancer. In the remaining foci, the uptake appeared nonsegmental, linear or lobar, suggesting a false-positive finding. The uptake was unchanged, variable in appearance or non-persistent on follow-up scans and less extensive than the fibrocystic changes seen on chest radiographs. In the two patients studied, thyroid hormone level did not affect the radioiodine lung uptake and there was congruent gallium-67 uptake. None of the patients had any evidence of thyroid cancer recurrence or of reactivation of tuberculosis and only two patients had chronic intermittent chest symptoms. Severe bronchiectasis, active tuberculosis, acute bronchitis, respiratory bronchiolitis, rheumatoid arthritis-associated lung disease and fungal infection such as Allescheria boydii and aspergillosis can lead to different patterns of radioiodine chest uptake mimicking pulmonary metastases. Pulmonary scarring secondary to tuberculosis may predispose to localized radioiodine accumulation even in the absence of clinically evident active infection. False-positive radioiodine uptake due to pulmonary infection/inflammation should be considered in thyroid cancer patients prior to the diagnosis of pulmonary metastases.

Sleep apnea syndrome: A report of 20 Saudi patients

Patients with sleep apnea syndrome (SAS) suffer considerable morbidity and increased mortality. The most common symptoms of SAS include excessive daytime sleepiness, nocturnal breath cessation, snoring and gasping sounds. We reviewed the characteristics of 20 Saudi patients with sleep apnea (15 males, five females) who were studied at our tertiary care center in 1992 and 1993. The ages ranged from 15 to 61 years. All were obese. Two each were acromegalic and hypothyroid. Hypertension was noted in seven (35%) patients and one had symptomatic bradycardia. Two (10%) patients presented with recurrent pulmonary emboli and two were involved in multiple road traffic accidents as a result of falling asleep while driving. One male student had poor performance at school. Three patients were known to have chronic obstructive airway disease. Six males and one female were hypercapnic (PCO2; > 6.1 kPa) while 10 patients had hypoxemia (paO2; < 8.0 kPa). Four patients were polycythemic. Pulmonary function tests showed that 15 (75%) had restrictive patterns, three (15%) had obstructive patterns and two (10%) had mixed patterns. A "saw-tooth" pattern was seen in the inspiratory limb of a flow-volume curve in four patients. Daytime polysomnography showed that eight had obstructive sleep apnea, four had central sleep apnea and six had mixed type sleep apnea. Both hypothyroid patients improved with replacement therapy; one acromegalic patient and one patient with tracheal stenosis responded to specific treatment. Nasal positive airway pressure machine (BIPAPtrade mark Resperonics Inc) was effective in relieving apnea and reducing symptoms in five patients. None of the patients were able to lose a substantial amount of weight. All these patients were investigated extensively at different places prior to establishing the diagnosis.

Open lung biopsy provides a higher and more specific diagnostic yield compared to broncho-alveolar lavage in immunocompromised patients. Fungal Study Group

In order to examine the feasibility and safety of undertaking a larger prospective study to compare the diagnostic yield from concurrent open lung biopsy (OLB) and bronchoalveolar lavage (BAL) in febrile neutropenic patients with pulmonary infiltrates and the impact of such knowledge on clinical outcome, a pilot exploratory study was performed. 13 immunocompromised patients (mainly with haematological malignancy or bone marrow transplantation recipients) were investigated. At least one diagnostic finding in 12 of 13 patients was provided by OLB compared to 4 of 13 patients by BAL. BAL provided 7 specific diagnoses (pneumocystis 1, fungal infection 3, bacterial pneumonia 1, pulmonary haemorrhage 2) whilst OLB provided 12 specific diagnosis (CMV 2, pneumocystis 3, fungal infection 1, bacterial pneumonia 1, pulmonary haemorrhage 4, pulmonary embolism 1). Five patients with nonspecific interstitial/alveolar inflammation were diagnosed only by OLB. The concordance that the exact same specific diagnoses present in the OLB were found in the BAL was zero. There were 2 minor complications (1 wound infection by OLB, 1 moderate haemorrhage by BAL). Mortality at 28 days was 8 of 13 patients which in no case was related to either procedure. We suggest that OLB is a safe procedure in such patients, provides superior and more complete diagnostic information compared to BAL and a larger controlled study to investigate the impact of early OLB on the outcome of these patients appears to be justified.

CT-guided fine needle aspiration biopsy in the diagnosis of mediastinal tuberculosis

Twenty-two patients with mediastinal tuberculosis were reviewed. The most common symptoms were chest pain, cough, fever, and weight loss. Results of the physical examination were unremarkable. The chest radiographs of all 22 patients showed abnormal mediastinum with no evidence of extramediastinal disease. Most (62%) had right-sided paratracheal lymphadenopathy. Mantoux skin test was positive (> 15 mm) in all patients, whereas sputum smears and cultures for acid-fast bacilli were negative. Computed tomographic (CT) guided fine needle aspiration biopsies (FNAB) were performed in 12 patients using 22- to 25-gauge needles. Ten patients had fiberoptic bronchoscopic (FOB) examination with brushings and biopsies. Mediastinoscopy (n = 8) or thoracotomy (n = 6) was performed in patients where either FNAB or FOB was not diagnostic or where lymphoma was suspected clinically. The rates of true-positive diagnoses were 20%, 66%, 75%, and 100% for FOB, FNAB, mediastinoscopy, and thoracotomy, respectively. The rate of false-negative for FNAB was 34%. Only one patient developed nonsignificant pneumothorax after FNAB. These findings suggest that CT-guided FNAB is a useful and safe procedure and should be considered in the initial evaluation of patients suspected of having mediastinal tuberculosis.

Total lung collapse after pulmonary infarction

A case is presented of total lung collapse secondary to intrabronchial blood clot as a complication of pulmonary infarction. The blood clot was removed at bronchoscopy with complete re-expansion of the lung.

Castleman's disease of the chest. Magnetic resonance imaging features

The value of magnetic resonance imaging (MRI) in the evaluation of vascular abnormalities in the chest is well established. To our knowledge, however, MRI in Castleman's disease of the chest had not been reported previously. We present a case of Castleman's disease of hyaline vascular type involving the pulmonary hilum where MRI was equal to computed tomography in showing the extent of the disease, but was more informative in demonstrating its relationship with vascular structures.

Sarcoidosis in native Saudis

Sarcoidosis is believed to be rare in Saudi Arabia. We report twenty cases of sarcoidosis among native Saudis followed-up at our tertiary care centre. The majority (55%) of these patients were referred as either tuberculosis or lymphoma. Twelve out of twenty patients had been or were being treated for pulmonary tuberculosis at the time of presentation. The clinical presentation of these patients was similar to the western pattern of disease with some differences such as severe constitutional symptoms (52%), relative frequent eye involvement (35%) and common occurrence of stage II changes on chest film (70%). Mantoux skin test was negative in nineteen patients (95%). Histological evidence of non-caseating granulomata was obtained in 19 patients. A positive correlation (p < 0.034) between constitutional symptoms and Angiotensin Converting Enzyme (ACE) levels was noted. Thirteen patients (65%) were treated with oral steroids while topical ophthalmic steroids were used in seven patients (35%). Functional and radiographic deterioration was observed in four patients (20%). Three patients went into respiratory failure including a patient who developed Hodgkin's lymphoma six years after the diagnosis of sarcoidosis. The epidemiology of sarcoidosis among native Saudis requires further studies.