Myeloid sarcoma (MS) is a rare malignant condition that is defined by an extramedullary collection of immature myeloid cells and occurs in 3% of acute myeloid leukemia (AML). The presence of isolated MS is synonymous for AML. Usual locations of MS include the skin, lymph nodes, and gastrointestinal tract (1). Although up to 16% of MS cases occur in the head and neck, reports of temporal bone MS are rare (2,3). The clinical presentation of MS typically occurs secondary to mass effect in these regions with nonspecific symptoms (2,4).There is no established treatment protocol; however, early and aggressive induction chemotherapy followed by radiation offers the best chances of survival (5). Longterm prognosis remains dismal; therefore, prompt recognition of MS is critical. Herein, we present a rare head and neck presentation of relapsing AML presenting as temporal bone MS.
CASEA 38-year-old man with a history of CKIT negative, AML with inv(16) had previously undergone 7 + 3 induction chemotherapy (fludarabine, cytarabine, idarubicin, and filgrastim), 4 cycles of consolidation, and a matched donor transplant. Ten months after bone marrow transplant, the patient was in morphologic remission. He presented to the emergency room 2 months later with a 3-week history of intermittent otalgia, sudden onset left-sided facial paralysis, and severe retroauricular pain. Physical examination revealed left-sided facial nerve palsy, HouseBrackmann 3/6, a left middle ear effusion, and tender left-side lymphadenopathy. The remainder of the examination was unremarkable with no other neurologic or rightsided symptoms.Subsequent CAT scan (CT) imaging revealed opacification of the mastoid antrum and mastoid air cells on the left, with a soft tissue mass with intracranial and extracranial components (Fig. 1). Magnetic resonance imaging was also obtained, which confirmed the CT findings with suggestion of extension of the lesion through the sigmoid plate into the mastoid (Fig. 2).The initial differential diagnosis included acute mastoiditis versus leukemic infiltration. Left-sided myringotomy with PE tube placement was placed upon presentation, and he was started on ofloxacin drops and 10 mg of dexamethasone IV. The results of the imaging prompted a CT-guided The authors disclose no conflicts of interest. FIG. 1. A, Axial CT soft tissue window reveals an approximately 3.2 cm AP Â 3.8 cm transverse lesion with an intracranial component approximately 2.0 cm AP Â 1.7 cm transverse. The extracranial component is within the retroauricular soft tissues and measures 8 mm in transverse and 2.6 cm in anteroposterior dimensions. This lesion was slightly hyperdense and blended with the sigmoid sinus. B, Axial CT bone window demonstrates permeation of the left sigmoid plate within the sigmoid groove and permeative destruction of the outer wall of the mastoid.
