Sarcoidosis: the significance of an acinar pattern on chest roentgenogram

Pulmonary Sarcoidosis Presenting with Acute Respiratory Failure: A Report of a Case Diagnosed by Endobronchial Ultrasound-guided Transbronchial Needle Aspiration on Ventilation after Intubation

Sarcoidosis is a multisystem granulomatous disease of unknown etiology and is pathologically characterized by non-caseating granulomas in the organs involved. We herein report a case of sarcoidosis in a Japanese woman with acute respiratory failure, diagnosed using endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) on the ventilator after intubation. Only a few cases of previously undiagnosed sarcoidosis presenting acute respiratory failure have been reported. It is important to be aware that undiagnosed sarcoidosis may present with acute respiratory failure. Therefore, EBUS-TBNA under mechanical ventilation may be useful for the immediate diagnosis of patients.

Sarcoidosis Presenting as Acute Respiratory Distress Syndrome

Sarcoidosis is a multisystem granulomatous disease of unknown origin. It typically involves the lungs and mediastinal lymph nodes in a chronic fashion. However, acute syndrome has been reported possibly in response to systemic release of proinflammatory cytokines. Acute pulmonary manifestations, especially acute respiratory failure or acute respiratory distress syndrome, remain extremely uncommon in individuals without a prior diagnosis. We present the case of a 41-year-old African American female, who presented with ARDS. An extensive workup into the cause of her illness remained negative, and she subsequently succumbed to her illness. A diagnosis of sarcoidosis was made upon autopsy, after exclusion of other granulomatous illness. The case highlights the need to consider this uncommon diagnosis in patients with unexplained ARDS to guide therapy.

Acute alveolar sarcoidosis presenting with hypoxaemic respiratory failure

Alveolar sarcoidosis is a less commonly seen pulmonary manifestation of the disease. An acute presentation of this radiological pattern with hypoxaemic respiratory failure has been documented only once, four decades ago. A 30-year-old man presented with acute onset of progressive and persistent dyspnoea over 20 days ago with hypoxaemic respiratory failure. Imaging demonstrated mediastinal lymphadenopathy and coalescent parenchymal alveolar opacities having ill-defined margins along with air bronchograms in the mid and lower zones bilaterally, suggestive of alveolar sarcoidosis. A restrictive pattern with a diffusion defect was seen on pulmonary function testing. Bronchoscopic evaluation revealed non-caseating granulomas on histopathology confirming pulmonary sarcoidosis. This was further supported by an elevated serum ACE level and negative Mantoux test. Oral prednisolone elicited a rapid clinical and radiological response. Alveolar sarcoidosis can rarely present acutely with hypoxaemic respiratory failure, which can respond remarkably and expeditiously to appropriate therapy.

Peripheral pulmonary infiltrates in sarcoidosis

The chest roentgenograms are described in eight patients with sarcoidosis who demonstrated a peripheral distribution of pulmonary infiltrates quite similar in appearance to that classically observed in eosinophilic pneumonia. The presence of mediastinal/hilar lymph node enlargement (eight patients), a nodular component to the infiltrate (four patients), an often asymptomatic presentation (four patients), and absence of blood eosinophilia (eight patients) should suggest the correct diagnosis.

Pulmonary sarcoidosis with an alveolar radiographic pattern

Thirty-three cases of sarcoidosis (4.4% of 746 patients) showed an alveolar radiological pattern. A study of pulmonary function was carried out in 25 patients and compared with that of 46 patients with the interstitial radiological type of sarcoidosis. Twenty-two cases have been followed up from one to six years after the initial examination. The radiographic lesions were most often bilateral and included nodules greater than 15 mm with ill-defined margins or diffuse, infiltrative, non-retractile opacities with fluffy margins. Bilateral mediastinal lymph nodes were present in 27 patients. In 20 patients an associated reticulation was found on radiography. In four patients an open lung biopsy was done. The granulomatous nodules were identical to those found in other forms of sarcoidosis, although they were more confluent in the affected areas. Clinical and functional findings did not differ from those in the more common forms of sarcoidosis. Alveolar sarcoidosis has a sudden course. The alveolar radiological patterns always disappeared, with or without steroid treatment, while reticular patterns persisted in four patients. Rapid radiological changes were observed. Some functional abnormalities persisted in cases that were followed. It is concluded that alveolar sarcoidosis is a distinct acute form of sarcoidosis.

Clinicopathologic characteristics of pulmonary acinar sarcoidosis

In 101 patients with histopathologic and clinical features compatible with sarcoidosis, a radiologic acinar pattern occurred in about 20% and was always accompanied by bilateral hilar lymphadenopathy. The radiologically acinar pattern histopathologically revealed noncaseating epithelioid granulomas and accumulations of macrophages in the alveolar spaces. Blood vessels were usually not affected by granulomas. On the other hand, a reticulonodular pattern histopathologically showed granulomas with centrally situated veins. The acinar form seems to represent the early stage of pulmonary sarcoldosis, producing primarily intra-alveolar lesions.

Acute pleurisy in sarcoidosis

A 47-year-old white man with sarcoidosis presented with a six-week history of acute painful pleurisy. On auscultation a loud pleural rub was heard at the left base together with bilateral basal crepitations. The chest radiograph showed hilar enlargement as well as diffuse lung shadowing. A lung biopsy showed the presence of numerous epithelioid and giant-cell granulomata, particularly subpleurally. A patchy interstitial pneumonia was also present. He was given a six-month course of prednisolone, and lung function returned to normal.

The clinical assessment of roentgenographically atypical pulmonary sarcoidosis

We studied 89 patients in whom the clinical diagnosis of sarcoidosis was supported by the findings on tissue biopsy. A chest roentgenogram in 14 of the patients showed one of the following atypical features: large pulmonary nodules, an alveolar parenchymal pattern or a pleural effusion. Diagnoses of infection, malignancy or vasculitis were suggested by interpretations of atypical chest roentgenograms in eight of these 14 patients. Nonspecific and misleading clinical information contributed. The diagnosis of sarcoidosis was corroborated by extrathoracic tissue biopsies in 11 of the 14 patients. Over an average observation period of 38 months, the 14 patients remained classified as having sarcoidosis. This suggests that an extrathoracic tissue biopsy, whose findings are consistent with sarcoidosis, is often sufficient to support a clinical diagnosis of some forms of roentgenographically atypical pulmonary sarcoidosis.