Pulmonary Mucormycosis in a Nondiabetic Renal Allograft Recipient Successfully Managed by Medical Therapy Alone

Abstract

Mucormycosis is a rare opportunistic infection that complicates solid-organ transplant recipients with exceedingly high mortality. Antifungal therapy combined with early surgical excision of infected necrotic tissue appears to be the preferred course of action (1). We describe a case of pulmonary mucormycosis in a renal allograft recipient that is unique in two aspects: the recipient was nondiabetic and he was successfully treated with medical management alone. A 45-year-old male renal allograft recipient of 5 years’ duration with stable graft functions presented with complaints of weight loss, low-grade fever, and cough with occasional hemoptysis of 2 months’ duration. He was on rapamycin 1 mg once daily, mycophenolate 1 g twice daily, and prednisolone 10 mg once daily for his immunosuppression. There was no for diabetes or hypertension. Laboratory examination revealed leukocyotosis (TC: 18,600/cu mm), normal blood sugars (fasting: 73 mg/dL, postprandial: 106 mg/dL), and serum creatinine 1.4 mg/dL. His blood culture and sputum culture were negative, whereas urine grew Escherichia coli. The radiograph showed consolidation in the left upper zone in the parmediastinal region with minimal pleural effusion on the left side. Pleural fluid was exudative (protein: 2 g%, glucose: 218 mg%, and white cell count: 60% polymorphs and 40% lymphocytes). High-resolution computed tomography of the thorax showed a subsegmental consolidation with central clearing at the apico-posterior and anterior segments in the parmediastinal region of the left lung. Transbronchial lung biopsy and subsequent percutaneous transthoracic biopsy showed necrotic tissue with no histopathological or microbiological evidence of infection or malignancy. Transbronchial lung biopsy done 3 weeks later was noncontributory. Ancillary investigations toward fever of unknown origin, including bone marrow, sputum for acid fast bacilli, echocardiograms and repeated blood cultures, were negative. In view of the persistent symptoms, an open lung biopsy was done. Macroscopic examination revealed a large area of necrotic tissue along the anterior and anteroposterior segments of the lung adhering to the arch of the aorta. Histopathological analysis revealed the presence of inflammatory cells and characteristic hypahe and fungae suggestive of mucormycosis (Fig. 1).FIGURE 1.: Aseptate broad fungal hyphae within necrotic material, upper lobe, left lung. (H&E, 40×)The proximity of the lesion to the aorta precluded surgical resection. Patient was managed medically with intravenous liposomal amphotericin B at 1.5 mg/kg for 3 weeks followed by voriconazole orally at 40 mg/kg for six weeks. His immunosuppressions were discontinued except for steroids. The patient became afebrile after 4 days, requiring no intensive care or surgical management. There was radiological improvement with stable graft function 5 weeks into treatment. He has been advised to continue voriconazole for a total duration of 12 weeks. Pulmonary mucormycosis is a rapidly progressive entity that carries a mortality rate of greater than 80%. Risk factors include prolonged neutropenia, diabetes, and immunosuppression (2). It can occur in any of several patterns and can mimic more common pneumonic processes. This mimicry, as well as the rarity of the disease, may delay diagnosis. Almost all cases described in literature pertain to transplant recipients, with underlying diabetes managed with combined surgical and medical therapy (1, 3, 4). Azoles and triazoles are thought not to be useful in therapy of zygomycosis; however, there is experimental evidence that the azoles or triazoles might have a beneficial effect in vivo against mucormycosis (5, 6). We gave the patient voriconazole for 3 months. Early consideration of this diagnosis, along with aggressive, including invasive diagnostic evaluation, is critical to effective therapy and patient survival. Amphotericin B and, in selected cases, surgical resection are the mainstays of therapy. The role of voriconazole as an adjuvant seems attractive and needs further consideration. Bobby Chacko Vinoi George David Veeraswamy Tamilarasi Department of Nephrology Christian Medical College Vellore, India Akkihebbal N. Deepti Department of Pathology Christian Medical College Vellore, India George T. John Department of Nephrology Christian Medical College Vellore, India