A 38-year-old man is undergoing treatment for acute myeloid leukemia. Initially, he had fevers and reported being lethargic and fatigued all the time. However, of late, he has noted increasingly severe right-sided headaches. He describes the pain to be throbbing in nature and located behind his right eye. He also has associated nasal stuffiness. The patient has no prior history of allergies. Physical examination reveals right-sided proptosis and periorbital tenderness. Biopsy of the right maxillary sinus mucosa reveals the following: Which of the following is the most likely cause of this patient's condition?

Question

A 38-year-old man is undergoing treatment for acute myeloid leukemia.  Initially, he had fevers and reported being lethargic and fatigued all the time.  However, of late, he has noted increasingly severe right-sided headaches.  He describes the pain to be throbbing in nature and located behind his right eye.  He also has associated nasal stuffiness.  The patient has no prior history of allergies.  Physical examination reveals right-sided proptosis and periorbital tenderness.  Biopsy of the right maxillary sinus mucosa reveals the following:  Which of the following is the most likely cause of this patient's condition?

Quizplus · Accepted Answer

11ec160b_3849_1e77_9249_6f58f34f8584_MD0001_00 Mucor, Rhizopus, and Absidia species are saprophytic fungi present in the environment. They are transmitted by spore inhalation and cause mucormycosis. Mucormycosis is very strongly associated with diabetic ketoacidosis. Patients with underlying immunosuppression (eg, due to solid organ transplantation, hematologic malignancies, or glucocorticoid therapy) are also at high risk. Mucormycosis tends to affect the paranasal sinuses. Symptoms include facial and periorbital pain, headache, and purulent nasal discharge. The fungi proliferate in the walls of blood vessels and cause necrosis of the corresponding tissue. Black eschar (necrotic tissue) may be seen on the palate or nasal turbinates. Mucormycosis is diagnosed by light microscopy of a tissue specimen. Mucor, Rhizopus, and Absidia fungi exist in mold form only. They form broad, nonseptate hyphae that branch at wide, often 90° angles. Mucormycosis is treated by surgical debridement of necrotic tissue and amphotericin B. (Choices A and B) Malassezia furfur and Microsporum canis cause cutaneous mycoses but do not affect the paranasal sinuses. (Choice D) Invasive aspergillosis involving the paranasal sinuses can show close clinical resemblance to mucormycosis. However, light microscopy of the affected tissue will differentiate these two diagnoses: unlike Mucor and Rhizopus, Aspergillus has septate hyphae that branch at 45° angles (V-shaped branching). (Choice E) Candida albicans can cause a variety of symptoms in immunosuppressed patients. Right-sided endocarditis, renal abscesses, and esophagitis are among the most common. Budding yeasts and pseudohyphae are seen on light microscopy. (Choice F) Cryptococcus neoformans primarily causes meningoencephalitis (eg, headache, confusion, altered mental state) in patients who are immunocompromised (particularly those with advanced AIDS). (Choices G, H, and I) Blastomyces, Histoplasma, and Coccidioides cause lung disease in healthy patients. Disseminated disease occurs in immunosuppressed individuals. Isolated paranasal involvement is not typical. (Choice J) Sporothrix schenckii can be transmitted to humans via subcutaneous inoculation. Manifestations include a papule at the site of exposure with subsequent papules forming along proximal lymphatic drainage pathways. Educational objective: Mucormycosis is an opportunistic infection caused by Rhizopus, Mucor, and Absidia species. The classic clinical picture is paranasal sinus involvement in a diabetic or immunosuppressed patient. The fungi form broad nonseptate hyphae that branch at right angles.

A 38-Year-Old Man Is Undergoing Treatment for Acute Myeloid Leukemia