Mucormycosis of the hard palate masquerading as carcinoma

Abstract

A growing number of medically compromised patients are encountered by dentists in their practices. Opportunistic fungal infections such as mucormycosis usually occur in immunocompromised patients but can infect healthy individuals as well. Mucormycosis is an acute opportunistic, uncommon, frequently fatal fungal infection, caused by a saprophytic fungus that belongs to the class of phycomycetes. Among the clinical differential diagnosis we can consider squamous cell carcinoma. Such cases present as chronic ulcers with raised margins causing exposure of underlying bone. There is a close histopathological resemblance between mucormycosis and aspergillosis. Microscopically, aspergillosis has septate branching hyphae, which can be distinguished from mucormycotic hyphae by a smaller width and prominent acute angulations of branching hyphae. A definitive diagnosis of mucormycosis can be made by tissue biopsy that identifies the characteristic hyphae, by positive culture or both. The culture of diseased tissue may be negative and histopathologic examination is essential for early diagnosis. Mucormycosis was long regarded as a fatal infection with poor prognosis. However with early medical and surgical management survival rates are now thought to exceed 80%. In the present case, the fungus was identified by hematoxylin and eosin stain and confirmed by Grocott's silver methenamine special staining technique. Removal of the necrotic bone, which acted as a nidus of infection, was done. Post-operatively patient was advised an obturator to prevent oronasal regurgitation. Since mucormycosis occurs infrequently, it may pose a diagnostic and therapeutic dilemma for those who are not familiar with its clinical presentation.

Keywords: fungal infection; mucormycosis; necrotic bone; phycomycetes; squamous cell carcinoma..

Figure 1

Clinical photograph showing ulcer with necrosis in the anterior palate extending to alveolar bone of left lateral incisor and canine (arrows showing the necrotic bone).

Figure 2

Computed tomography scan showing focal destruction of the bone of anterior palate (circled area) to the left anterior maxillary region (arrow).

Figure 3

Intra-operative image showing the area after the removal of necrotic bone.

Figure 4

Photograph showing superior view of surgical specimen with involved teeth.

Figure 5

Microphotograph showing non-septate branched fungal hyphae in a necrotic tissue (H & E stain, Original magnification ×250).

Figure 6

Microphotographs showing non-septate, broad, branched fungal hyphae (H & E stain, Original magnification ×400).

Figure 7

Post-operative photograph showing the oro-nasal fistula (arrows).

Figure 8

Photograph showing the obturator for the oro-nasal fistula.