Nodular Sarcoidosis: An Unusual Radiographic Appearance

Sarcoidosis has a wide varying presentation. Pulmonary sarcoidosis typically presents with bilateral hilar adenopathy and reticulonodular opacities. Very rarely it can present as a single solitary mass. Here we present a case of a 39 year old African-American male who presented with cough and pleuritic chest pain. Initial imaging revealed a right lower lobe airspace opacity, concerning for pneumonia. Despite treatment with antibiotics, symptoms and radiological findings persisted. A PET scan revealed a FDG positive right lower lobe pulmonary mass. Biopsy of the mass and lymph nodes revealed non-caseating granulomas suggestive of sarcoidosis. This case showcases a rare presentation of pulmonary nodular sarcoidosis.

Sarcoidosis is a multi-system disease of unknown etiology, usually affecting the respiratory tract and other organs, and is characterized by the formation of nonnecrotizing epithelioid granulomas. The diagnosis depends on a combination of a typical clinicoradiological presentation, the finding of nonnecrotizing epithelioid granulomas in a tissue biopsy, and exclusion of other possible diseases, especially those of infectious etiology. The granulomas contain epithelioid cells, giant cells, CD4+ T cells in their center, and CD8+ T lymphocytes and B lymphocytes at their periphery. The granulomas are present in a lymphatic pattern around bronchovascular structures and, because of this, may show angioinvasion. The bronchial involvement produces a high diagnostic yield for transbronchial and endobronchial biopsies in this disease. Finally, small amounts of fibrinoid necrosis may occur within granulomas of sarcoidosis and do not exclude the diagnosis. Larger amounts suggest either infection or the rare disease necrotizing sarcoid granulomatosis (NSG). A number of cytoplasmic structures/inclusions can be identified within the granulomas of sarcoidosis, including asteroid bodies, Schaumann’s bodies, calcium oxalate crystals, and Hamazaki–Wesenberg bodies; the last two of these can cause difficulties in differential diagnosis. Extra-pulmonary sarcoid can be an important factor in prognosis. Involved sites include (in decreasing frequency): skin, endocrine organs, extra-thoracic lymph nodes, neurologic sites, eyes, liver, spleen, bone marrow, cardiac, ear/nose/throat, parotid/salivary, muscles, bones/joint, and kidney. NSG is a controversial variant of sarcoidosis consisting of granulomatous pneumonitis with sarcoid-like granulomas, variable amounts of necrosis, and granulomatous vasculitis. The lesions are most often confined to lung, and they usually appear as multiple nodules or nodular infiltrates, but occasionally as solitary or unilateral nodules ranging up to 5 cm in diameter. Nodular sarcoidosis is rare, varying from 1.6% to 4% of patients with sarcoidosis, and, as the name suggests, it shows radiographic nodules measuring 1 to 5 cm in diameter that typically consist of coalescent granulomas. Lung transplantation can be used in selected patients with fibrotic late-stage sarcoidosis. There is a high reported frequency of recurrence of disease in the pulmonary allograft, ranging from 47% to 67%, but recurrence is usually not clinically significant. Studies of the pathogenesis of sarcoidosis suggest that it is a chronic immunological response produced by a genetic susceptibility and exposure to specific environmental factors.

A 59-year-old woman, who was given a diagnosis of sarcoidosis by supraclavicular lymph node biopsy 5 years previously, was admitted for further examination following abnormal radiologic findings. Nodular pulmonary and abdominal lesions were observed by computed tomography, and liver biopsy was performed and showed epithelioid cell granulomas. She was asymptomatic and was followed up with no therapy. At 1 year follow-up, the pulmonary and abdominal lesions had nearly complete resolution. Nodular pulmonary and abdominal lesions in patients with sarcoidosis can mimic metastatic disease, lymphoma, and infection, and can reappear during disease activity. Therefore, differential diagnosis and continual follow-up are important.

Sarcoidosis is a multi-system disease of unknown etiology, usually affecting the respiratory tract and other organs, and is characterized by the formation of nonnecrotizing epithelioid granulomas. The diagnosis depends on a combination of a typical clinicoradiological presentation, the finding of nonnecrotizing epithelioid granulomas in a tissue biopsy, and exclusion of other possible diseases, especially those of infectious etiology. The granulomas contain epithelioid cells, giant cells, CD4+ T cells in their center, and CD8+ T lymphocytes and B lymphocytes at their periphery. The granulomas are present in a lymphatic pattern around bronchovascular structures and, because of this, may show angioinvasion. The bronchial involvement produces a high diagnostic yield for transbronchial and endobronchial biopsies in this disease. Finally, small amounts of fibrinoid necrosis may occur within granulomas of sarcoidosis and do not exclude the diagnosis. Larger amounts suggest either infection or the rare disease necrotizing sarcoid granulomatosis (NSG). A number of cytoplasmic structures/inclusions can be identified within the granulomas of sarcoidosis, including asteroid bodies, Schaumann’s bodies, calcium oxalate crystals, and Hamazaki–Wesenberg bodies; the last two of these can cause difficulties in differential diagnosis. Extra-pulmonary sarcoid can be an important factor in prognosis. Involved sites include (in decreasing frequency): skin, endocrine organs, extra-thoracic lymph nodes, neurologic sites, eyes, liver, spleen, bone marrow, cardiac, ear/nose/throat, parotid/salivary, muscles, bones/joint, and kidney. NSG is a controversial variant of sarcoidosis consisting of granulomatous pneumonitis with sarcoid-like granulomas, variable amounts of necrosis, and granulomatous vasculitis. The lesions are most often confined to lung, and they usually appear as multiple nodules or nodular infiltrates, but occasionally as solitary or unilateral nodules ranging up to 5 cm in diameter. Nodular sarcoidosis is rare, varying from 1.6% to 4% of patients with sarcoidosis, and, as the name suggests, it shows radiographic nodules measuring 1 to 5 cm in diameter that typically consist of coalescent granulomas. Lung transplantation can be used in selected patients with fibrotic late-stage sarcoidosis. There is a high reported frequency of recurrence of disease in the pulmonary allograft, ranging from 47% to 67%, but recurrence is usually not clinically significant. Studies of the pathogenesis of sarcoidosis suggest that it is a chronic immunological response produced by a genetic susceptibility and exposure to specific environmental factors.

La sarcoïdose est une granulomatose systémique bénigne, d’étiologie inconnue. L’atteinte parenchymateuse interstitielle est habituelle. La forme pseudo-alvéolaire est atypique, souvent d’installation aiguë, de diagnostic difficile mais d’évolution rapidement favorable sous corticothérapie.

Dans le présent travail, les auteurs rapportent deux cas de sarcoïdose pseudo-alvéolaire de présentations radiologiques et cliniques distinctes et déroutantes chez de patients jeunes de sexe masculin.

À travers ce travail les auteurs mettent l’accent sur la rareté de cette forme pseudo-alvéolaire et sur ses caractéristiques radiologiques. Ils insistent sur la difficulté d’en faire le diagnostic précoce et l’intérêt d’y penser précocement pour éviter tout retard de prise en charge. Ils soulignent enfin la grande sensibilité de cette forme inhabituelle de la sarcoïdose à la corticothérapie et proposent une revue de la littérature.

Sarcoïdosis is a benign systemic granulomatosis whose aetiology remains unknown. Lung is the most frequently involved organ. The pseudoalveolar form of this disease is known to have an acute onset and is quite uncommon. Therefore, diagnosing such a rare variety of sarcoidosis is rather often challenging.

In the present article, the authors report two cases of pseudoalveolar sarcoidosis. The patients, both young adults, showed no suggestive signs of sarcoidosis at first presentation. This resulted in a considerable delay to diagnosis and to the corticosteroid therapy.

The authors emphasize the rarity of the pseudoalveolar form of sarcoidosis. They insist on its roentgenographic characteristics and demonstrate the functional benefits allowed by the precocious medical management. They also propose a current review of the literature.