Case Presentation: A 63 y/o male presented with complaint of nonproductive cough and syncope for 1 month prior to arrival. He was without fever, chills or recent sick contacts. The syncope was non-positional and was without warning symptoms. He was without bowel or bladder incontinence and was non-ictal after syncopal episodes. He had decreased appetite 1 month prior to admission and had diarrhea with multiple episodes of loose, non-bloody stools daily. He endorsed a 60 lb unintentional weight loss and social history was significant for EtOH abuse and 49-pack year history of smoking. He worked in construction and demolition in a downtown metropolitan area. Of note, 1-month prior he was admitted for similar complaints during which time he was found to have multiple lung masses. Biopsies of the masses were nonconclusive and further workup for masses was scheduled as outpatient. During admission, CTA chest was without PE, but confirmed 3 enlarging lung masses. PET scan showed hypermetabolic enlargement of the right thyroid lobe. MRI head was with rim enhancing lesion of the right cerebellar and left parietal mass. Brain biopsy and thyroid biopsy along with repeat biopsy of lung lesion were consistent with disseminated Nocardiosis. Patient was started on IV Bactrim, Merrem, and Linezolid empirically for disseminated nocardia with CNS abscesses.
Discussion: Nocardia is a gram positive, acid fast with beaded filaments, rod shaped bacteria commonly found in soil and is a normal oral flora in gingiva and in periodontal pockets. As an opportunistic bacterium it is most frequently seen in immunocompromised hosts particularly those with depressed cell-mediated immunity, as seen in chronic steroid use, organ transplantation and AIDS. Most Nocardia infections occur through inhalation or trauma, with 70% constituting isolated pulmonary infections. Of the 30% of extrapulmonary infections there is a particular predilection for cerebral abscess formation. Only 2% of all cerebral abscesses are caused by nocardia, however incidence is increasing. Mortality rates for Nocardial CNS abscesses are around 30% for immunocompetent and 60% for immunocompromised hosts, compared to 10% average for other CNS abscesses. Only 10 cases of suppurative thyroiditis are reported in literature. It is rarely seen due to “relative anatomical isolation of the gland due to its encapsulation, rich blood supply and lymphatic drainage, and the antibacterial effect of high iodine concentrations.”
Conclusions: Initially our patient appeared to have metastatic cancer, as he had multiple lung nodules, was a smoker, and had 60-pound unexplained weight loss. Biopsies including brain, thyroid and lung were performed to rule out malignancy as he was thought to be in an immunocompromised state. Fortunately, our patient was without cancer, and was immunocompetent, making nocardial dissemination to the thyroid all the rarer. Nocardia can mimic primary metastatic cancers, and granulomatous disease and has a predilection to cause CNS infections, often times mimicking tumors until biopsies are performed. While this case did not have thyroid hormonal derangements, it represents an exceedingly rare cause of thyroid infection which was only picked up on PET scan. After completing a prolonged course of IV antibiotic infusions, our patient has made almost a full recovery. He remained without systemic thyroid toxicity, and aside from peripheral neuropathy, has made a full neurological recovery.