Copyright ©ERS Journals Ltd 2002 doi: 10.1183/09031936.02.00632002
An African male with cough, haemoptysis, weight loss and hypercalcaemia: TB or not TB?1 Dept of Medicine and 2 Dept of Pathology, College of Medicine, King Saud University, Riyadh, Saudi Arabia CORRESPONDENCE: A.F. Al-Mobeireek, Dept of Medicine (38), College of Medicine, King Saud University, P.O. Box 2925, Riyadh, 11461, Saudi Arabia. Fax: 966 14672686. E-mail: mobeireek@yahoo.com Case history A 60-yr-old Sudanese male was referred to the University Hospital, Riyadh, Saudi Arabia, with the chief complaints of chronic cough productive of scanty sputum and occasional haemoptysis, anorexia and weight loss for 9 months. The patient was extensively investigated in other hospitals and was treated as a pulmonary tuberculosis (TB) patient on the basis of lymphocytic pleural fluid cytology and the finding of granuloma on pleural biopsy. He continued to get worse, despite receiving four anti-TB drugs for the previous 4 months. The patient's course was complicated by hypercalcaemia, which failed to respond to steroids and saline diuresis and required calcitonin. He also developed right-sided pneumothorax, which required prolonged thoracostomy drainage. He was a nonsmoker and worked as a painter. On physical examination, the patient was cachectic, depressed and had finger clubbing. Furthermore, he had findings consistent with right pleural effusion.
A summary of investigations is shown in table 1
BEFORE TURNING THE PAGE, INTERPRET THE RADIOGRAPHS AND HISTOLOGICAL EXAMINATIONS AND SUGGEST A DIAGNOSIS. Interpretation
Chest radiography
Computed tomography
Histological examination Diagnosis: "Primary pulmonary lymphoma (B-cell)"
Hospital course Discussion
Although TB is endemic in the patient's geographical location and the clinical picture is compatible with TB (including hypercalcaemia 1), a definite microbiological or histological proof was lacking. Granulomas without acid-fast bacilli or positive mycobacterial culture are not specific; a variety of infectious and noninfectious causes may be responsible (table 2
A diagnosis of sarcoidosis is supported by the presence of granulomas, hypercalcaemia, hypergammaglobulinaemia and a negative tuberculin test. All these features were present in the patient, except that he also had pleural effusion, which is unusual for sarcoidosis. He was also given steroids, without clinical improvement. The presence of elevated erythrocyte sedimenta<1?show=[fo]>tion rate, anaemia, hyperproteinaemia, hypercalcaemia and renal insufficiency should also raise the possibility of multiple myeloma. This diagnosis is ruled out, however, by the negative bone marrow, the polyclonal nature of the gammopathy and the absence of Bence-Jones protein in the urine. Secondary amyloidosis, complicating his chronic pulmonary disease, may be considered because of the hypergammaglobulinaemia, hepatomegaly and renal insufficiency. Again, this is unlikely because of the relatively short period of his illness, the negative rectal biopsy and the radiological picture.
Carcinomatosis with hypercalcaemia is another consideration, but there was no evidence clinically or radiologically pointing to a primary tumour, and multiple organ biopsies were negative. In addition, many other conditions can cause pulmonary granuloma (not necessarily associated with hypercalcaemia), but there was no clinical or laboratory evidence to support any of these (table 2
This leaves primary pulmonary lymphoma (PPL) for consideration, taking into account the histological picture and the lack of evidence of lymphoma elsewhere. PPL is not common, representing The most common types of low-grade B-cell PPL are well-differentiated lymphomas that originate from the mucosa-associated lymphoid tissue (low-grade MALT lymphoma). The typical site of MALT lymphoma in humans is the gastrointestinal tract. It has also been described in conjunctiva, salivary, thyroid and thymus glands. Most maltomas arise in the setting of an autoimmune disease or chronic antigenic stimulation. Involvement of the lung was described by Addis et al. 6 in 1988. Pulmonary maltomas are most often indolent and remain localised in the lung for long periods. Epithelioid granulomas are known to be seen in pulmonary lymphoma. In one study 7, they were observed in 20% of 54 cases of low-grade malignant lymphoma. Their presence may be responsible for an erroneous diagnosis of TB in a small biopsy specimen, and their presence in conjunction with diffuse dense lymphoid infiltrate should be interpreted cautiously. Several ancillary methods (e.g. genetic analysis, multiparametric flow cytometry and gene amplification pattern) can be applied when working with small biopsies and cytological samples 8, 9. In conclusion, lymphoproliferative diseases affecting the lung occur over a broad clinicopathological spectrum. Pulmonary lymphoma can mimic many diseases and should be considered in the differential diagnosis. Diagnosis can be difficult, as it requires adequate tissue sampling and a skilled pathologist. The presence of granulomas should not lead to the erroneous diagnosis of granulomatous diseases, particularly in the prescence of clonal lymphoplasmacytic infilterate, and if the clinicopathological setting is not typical.
Acknowledgements The authors are grateful to A. Rikabi for reviewing the manuscript. References
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