RHINOCEREBRAL MUCORMYCOSIS

Rhinocerebral mucormycosis: a systematic review of case reports and case series from a global perspective

OBJECTIVE

Rhinocerebral mucormycosis (RCM) is the most common variant and the presenting features in the head and neck region are seldom pathognomonic. The aim of this systematic review was to obtain a thorough insight into the predisposing factors, clinical features, disease course, management protocol, outcome, and prognosis.

STUDY DESIGN

An electronic search was carried out using MEDLINE by PubMed, Scopus, Google Scholar, Web of Science, and EMBASE databases. Articles in which the clinical findings on the extra- and intraoral features of RCM were included for systematic review. Descriptive statistics was applied to obtain the results.

RESULTS

A total of 124 case studies (90 case reports, 34 case series) which yielded 219 patients. Diabetes mellitus (57.40%) was the most common comorbid condition. Neurologic manifestations were noted in 23.3% of the individuals. Maxillary/hard palate involvement was a common occurrence (59.2%). Intra-oral necrotic lesions with eschar were noted in 75/219 patients. Amphotericin B was the commonly used drug for the management, and surgical debridement was performed in majority of the cases. The mortality rate was 18.4%.

CONCLUSIONS

The clinical manifestations often mimic odontogenic symptoms, hence a sound knowledge about the pathogenesis and course of the disease will aid in the prompt diagnosis and management.

Identification of the asexual state of Rhizopus species on histologic tissue sections in a patient with rhinocerebral mucormycosis

Mucormycosis is an infection caused by a group of fungi in the order Mucorales in the phylum Zygomycota. The most well-known form of this disease is rhinocerebral mucormycosis, which usually develops in diabetic or immunocompromised patients. The fungal hyphal elements are easily detected in biopsy specimens by direct or histologic examination. However, the confirmatory identification of the genus or species requires culture of the specimen. This article presents a case of rhinocerebral mucormycosis in which presumptive identification of the genus was made without microbiologic cultures and was based on the extraordinarily rare appearance of fungal sporangia and sporangiospores in histologic tissue sections. Identification of these structures allowed an early and accurate diagnosis of rhinocerebral invasive mucormycosis.

Mucormycosis of the mandible

A case of mucormycosis of the mandible and adjacent soft tissue is presented. The rampant osteomyelitis that developed over a two-month period shows the necessity of early medical and surgical intervention. The management of these patients includes aggressive medical management of underlying problems, high-dose amphotericin B administration, and early surgical debridement of all involved tissues.

Mucormycosis of the temporal bone

Mucormycosis of the temporal bone is described in a 60-year-old female with uncontrolled diabetes mellitus whose symptoms related to cranial nerve palsies and hearing loss, following spread of infection from the nasopharynx. The infection spread along the eustachian tube and tensor tympani muscle to the base of the skull, involving the internal carotid artery with mycotic thrombosis and rupture. Subsequent spread occurred from this area predominantly along nerve pathways and as mycotic emboli in blood vessels of the labyrinth and middle ear. Infection also spread from the anterior middle ear wall through the oval window into the vestibule. The temporal bone changes were those of granulomatous inflammation with necrosis and ischemic infarction.

Lethal rhinocerebral phycomycosis in a healthy adult: a case report and review of the literature

A lethal case of rhino-orbital-cerebral phycomycosis (mucormycosis) in an otherwise healthy man is presented. The clinical, radiologic, and ante mortem surgical pathology associated with microbiologic examinations failed to yield the diagnosis of fungal infection as the cause of a clinical presentation of acute sphenoid sinusitis with a fulminant cavernous sinus thrombosis. No similar case report was found in review of the literature. There is a need for a high degree of suspicion in this condition to improve the uniformly poor prognosis in this devastating infectious disease. Emphasis is placed on the necessity for early tissue or microbiologic diagnosis with appropriate histologic stains and fungal cultures. Treatment consists of extensive surgical excision of all necrotic or questionably viable tissue in conjunction with alternate-day amphotericin B therapy.

Rhinocerebral zygomycosis treated with amphotericin B

Rhinocerebral zygomycosis is a rare, often fatal opportunistic fungal infection involving the cranial tissues. A diabetic patient with normal humoral and cellular immunity who was successfully treated with amphotericin B and surgery is reported.

Ocular and orbital phycomycosis

Cerebro-rhino-orbital phycomycosis (CROP) occurs predominantly in individuals with diabetes mellitus in a state of metabolic acidosis. Other forms of metabolic acidosis, especially in infants, may predispose to phycomycotic infections. CROP has also been reported in patients with leukemia or lymphoma. CROP usually begins in the palate or paranasal sinuses and rapidly spreads to the orbital contents. Proptosis, loss of vision, and ophthalmoplegia occur and death from cerebral involvement commonly ensues. The fungus tends to invade arteries and cause thrombosis and tissue infarction. Rhizopus is the most commonly isolated genus in CROP, accounting for almost all cases. The diagnosis can be strongly suspected by the characteristic clinical manifestations. Therapy includes treatment of the underlying disease, surgical excision of the necrotic tissue containing fungal elements and the systemic administration of amphotericin-B. The effect of treatment has improved since the disease was first described, but the condition still has a high mortality, especially if it is not diagnosed early.

Chronic rhinocerebral phycomycosis in association with diabetes

Two patients with rhinocerebral phycomycosis associated with diabetes are presented. The chronic nature of the illness in these two cases in emphasized in contrast to the more fulminant course of most previously reported patients. A high index of suspicion is needed to establish the diagnosis as rapidly as possible. Treatment of the underlying disease combined with amphotericin B therapy and radical surgical excision of all infected tissue is important to establish cure of these patients.

Mucormycosis

Three cases of mucormycosis are presented; two with unusual aspects: one with previously unreported involvement of the mandible, and one presenting as a cavernous sinus thrombosis. Review of the literature reveals a limited number of survivors. Survival in two of the cases presented here suggests that early diagnosis, aggressive therapy with surgery, and amphotericin B should improve the prognosis.

Cerebral mucormycosis following open head trauma. Case report

The authors describe a case of human cerebral mucormycosis following open head trauma and craniotomy, and discuss possible roles of steroids and antibiotic therapy in its pathogenesis. They suggest that the common usage of prolonged broad-spectrum chemoprophylaxis in head trauma may require critical review.

Phycomycosis of the bronchus

A case of phycomycosis of the bronchus in a 29-year-old diabetic man is reported. The interval between infection and death was not less than 35 days. Infection of the bronchus appears to have been direct. The diagnosis of phycomycosis could have been made before death.