Myeloid sarcoma: An unusual and rare laryngeal presentation.

INTRODUCTION: Myeloid Sarcoma (MS) or Granulocytic Sarcoma is an uncommon laryngeal malignancy. It may arise from myelodysplastic syndromes, malignancy or de novo. Presentation in the larynx is rare and some may present with Acute Myeloid Leukaemia (AML) whereby the later may be asymptomatic.

CASE PRESENTATION: A 44-year-old South East Asian lady presented with a six months history of hoarseness, shortness of breath, reduced exercise tolerance, weight loss and laryngeal irritation. Symptoms progressed to coughing with liquids two months prior. On examination, she had a resting biphasic stridor and laryngoscopy revealed right immobile vocal cord with a firm right ventricle mass extending into the right paraglottic space. She was pale and haematology investigations revealed microcytic hypochromic anaemia. Magnetic Resonance Imaging (MRI) of the neck and thorax showed thickening of the right false cord, true cord and aryepiglottic fold. A biopsy taken during endolaryngeal microsurgery (ELMS) confirmed myeloid sarcoma of the right ventricle and para glottic mass. Further investigation revealed a background of AML and she then underwent chemotherapy.

DISCUSSION: MS is a rarity with only nine reported cases between the years of 1954 until 2015. Immunohistochemistry and immunophenotyping are definite for diagnosis confirmation as MS cells often exhibit myeloperoxidase (MPO), lymphocyte common antigen (LCA) and CD117 markers. MS is treated with are chemotherapy (either systemic or intrathecal), radiotherapy, surgical excision or in combination. Systemic chemotherapy has better efficacy and prognosis as compared to localised treatment of radiotherapy or surgical excision. However, there has yet to be a definitive chemotherapy protocol. Prognosis is poor with a 5-year survival rate of 48%.

CONCLUSION: Although laryngeal MS is a rare phenomenon, early recognition is key and patients should always be investigated for an underlying myeloproliferative or dysplastic disease.