Plasma cell granuloma of the lung: difficulties in diagnosis and prognosis

Abstract

Background: The nature of plasma cell granuloma of the lung is still not well defined. Its diagnosis can be difficult, and its long-term prognosis is uncertain.

Methods: Four patients, aged 4 1/2 to 45 years, had resection of a circumscribed plasma cell granuloma. In 1 of them, it was associated with a carcinoma. The fifth patient was treated by irradiation for an invasive form of plasma cell granuloma, which was diagnosed as malignant lymphoma 1 year later. The plasma cell granulomas had a similar polymorphic pattern and were polyclonal at immunohistochemistry.

Results: The 3 patients treated by lobectomy, including the patient with an associated carcinoma, were alive and well at 12, 12, and 11 years postoperatively. The patient treated by pneumonectomy had recurrence 9 years later and died 11 years after operation: irradiation was not effective. The patient with lymphoma was treated by chemotherapy and was alive and in remission 5 years later.

Conclusions: An accurate preoperative diagnosis is difficult. The results of biopsy can be inconclusive, and an associated malignancy can be missed. Complete resection remains the best treatment. The long-term prognosis is unpredictable, and late and fatal recurrences are possible.