Parkland Morning Report: Pulmonary Mucormycosis

This week at Parkland, Dr. Thomas Rose presented an interesting case of pulmonary mucormycosis in a 19-year old presenting in DKA.  Fortunately, through quick identification and appropriate management, the patient is back at home and continuing to improve 6 months after her initial presentation!

Mucormycosis is most common in diabetics, but is also seen in other immunosuppressed patients with hematologic malignancies or following solid organ or hematopoietic stem cell transplant.

Rhino-orbital-cerebral infection is the most common presentation and usually presents as acute sinusitis and can rapidly progress to orbital and cerebral involvement.  70% of rhino-orbital-cerebral infection occurs in diabetics, usually with DKA.  Other sites of infection include GI, Renal, Cutaneous, and Pulmonary.

Pulmonary mucormycosis is rare.  Reported cases have historically shown that pulmonary disease occurs mostly in diabetics (~50%), hematologic malignancies (~30%), CKD patients (~10%), and organ transplant recipients (~10%).

Presenting symptoms are usually cough and fever.  Dr. Rose’s patient presented with no fevers, but thick blood-streaked sputum and AMS in severe DKA.  Imaging typically shows consolidations or multiple nodules, often with effusions.  Cavities are less commons (~25%), but were seen in our patient as shown below:

pulmonary mucor PA

ct mucor

Diagnosis can be difficult, and you must have a high index of suspicion given the rapid progression of disease.  Bronchoscopy is the most common method of diagnosis, and our patient underwent bronchoscopy and BAL, which grew Rhizopus.  Unfortunately, only ~25-50% of cultures are positive, so histology (>90% sensitive) may be needed from bronchoscopic, thorascopic, or open approaches.

Treatment is most effective with a combined medical and surgical approach with all efforts to control the underlying disease (DKA, immunosuppression).  IV amphotericin is the drug of choice and should be started as soon as possible – delay in treatment >6 days in those with hematologic malignancies resulted in a 2-fold increased in mortality.  Equally important is aggressive surgical debridement to prevent further invasion into surrounding structures.  After several weeks of amphotericin with favorable clinical response, patients can be stepped down to posaconazole or isavuconazole to be continued until clinic resolution and reversal of underlying immunosuppression, if feasible.

Outcome is poor for all forms of mucormycosis, but survival seems to be increasing.  Rhinocerebral disease mortality ranges from 25-62%, and prognosis is best in those with disease confined to sinuses.  Pulmonary disease, on the other hand, has mortality rates ranging from ~45-87%, due to difficulty with surgical cures, complications of massive hemoptysis, and the severity of underlying conditions.

Great job to the team on identifying the disease early and effectively treating this young woman!  She was appropriately started on amphotericin and underwent multiple lobectomies.  For antifungal therapy, she completed 3 months of amphotericin before she was stepped down to isavuconazole.  She is now back at home and continuing to improve!

 

Citations:

Lee FY, Mossad SB, Adal KA. Pulmonary mucormycosis: the last 30 years. Arch Intern Med 1999; 159:1301.

Chamilos G, Lewis RE, Kontoyiannis DP. Delaying amphotericin B-based frontline therapy significantly increases mortality among patients with hematologic malignancy who have zygomycosis. Clin Infect Dis 2008; 47:503.