The patient was a 27 year old male who presented to the ED in July 2016 with persistent left sided chest pain and a lump over his sternum of several weeks in duration. Pain was exacerbated by touch and exertion. Other symptoms included occasional episodes of scant hemoptysis. Patient denied SOB, fevers, chills, night sweats, unintentional weight loss, sick contacts, or recent travel.
He was previously diagnosed with left upper lobe CAP in February 2016 and was treated with azithromycin. He subsequently returned to the ED in April complaining of cough and expectoration; repeat chest x-ray showed persistent infiltrate and patient was treated with a course of levofloxacin. The patient was seen by a pulmonologist during a clinic visit in June and a CT chest was ordered, but patient was lost to follow-up.
Patient had no other significant medical history or contributory family history. Social history was remarkable for social alcohol use and daily marijuana use.
After admission, workup of his symptoms was initiated including CT chest which revealed several sternal and thyroid lesions. Other lab work included fungal serologies and biopsies of both his sternal and thyroid lesions. Pulmonology and infectious disease specialists were consulted to assist in management. Pertinent imaging and patholgy results are summarized as follows:
CT Chest: remarkable for airspace opacity of posterior left upper and lower lobe (5.3 x 2.0 x 7.3cm). Destructive lesion and soft tissue mass was noted in the sternum. Additionally, a 1.3cm hypoattenuating nodule seen in the left thyroid lobe.
Thyroid Ultrasound: 2.7 cm irregular hypoechoic mass in the midportion of the left lobe of thyroid gland
Thyroid FNA: Fragments of lymphohistiocytic aggregates suggestive of granulomatous change.
Sternum Core Biopsy: Acute granulamtomous inflammation and abscess formation. Silver stain negative for fungal organisms. Kinyoun stain negative for acid fast organisms.
Sternal Mass Culture: DNA probe test positive for Blastomyces dermatitidis.
Serology revealed Blastomyces and patient was subsequently started on voriconazole. Patient complained of visual disturbances and was switched to IV amphotericin B; however he soon developed renal failure. He was finally switched to itraconazole which he tolerated without any adverse reactions.
Discussion:
Blastomycosis is caused by a dimorphic fungus endemic to north central/southern US, Canada, and parts of Africa. It is transmitted by inhaling decomposing wood or vegetation. Infections are often asymptomatic, but can present with self-limited pulmonary infections. Sputum in blastomycosis is generally purulent (unlike in histoplasmosis). Extrapulmonary manifestations can be seen in 25-40% of cases. Studies indicate prevalence of bony lesions to be about 25%, but thyroid lesions are very rare.
Mild to moderate pulmonary disease can be treated with an oral azole such as itraconazole. For severe disseminated disease, CNS involvement, or infections in immunocompromised patients, initial treatment is amphotericin B with step-down to an oral azole after clinical improvement. If under-treated, blastomycosis has a high rate of relapse. Treatment must last 6-12 months.
Conclusions:
Blastomycosis typically presents as a pulmonary infection. However, this case demonstrates that practitioners should always be mindful of disseminated extrapulmonary manifestations of this disease, which aren’t uncommon. A high clinical suspicion would help with early diagnosis and appropriate treatment.