Retro-orbital nocardiosis masquerading as a neoplasm- A case report

Nocardiosis caused by an aerobic gram positive, weakly acid fast actinomycete is a localized or disseminated infection. The disease usually affects patients with defective cell mediated immunity. These infections are infrequent but pose a great challenge in terms of diagnosis and treatment as the treatment is prolonged and relapse is known to occur. The incidence has been increasing recently which can be attributed to the improvements in diagnostic facilities and increased prevalence of patients with HIV, chronic alcoholism, diabetes mellitus, patients receiving aggressive antineoplastic chemotherapy, long standing corticosteroid therapy and patients undergoing organ transplantation with immunomodulator drugs. Nocardiosis has been described in patients with underlying chronic pulmonary diseases. Primary nocardial infection includes pulmonary (60-70%), brain, musculoskeletal system and cutaneous or subcutaneous lesions. Disseminated disease is defined by the nocardial involvement in two or more organs. Nocardiosis associated with HIV usually appears in patients with advanced disease with CD4 counts less than 50 cells/mm3. Sulfonamides like trimethoprim-sulfamethoxazole are the drugs of choice for nocardiosis and are successfully used for treatment. Nocardiosis has been described to mimic tuberculosis, aspergillosis, bronchogenic and metastatic lung carcinomas, brain and musculoskeletal tumours. Here we describe an unusual presentation of retro-orbital nocardiosis masquerading as a neoplasm which was successfully treated with cotrimoxazole and ceftriaxone.