Fine needle aspiration in the pre-operative diagnosis of melanotic neuroectodermal tumour of infancy

Abstract

A case of melanotic neuroectodermal tumour of infancy is decribed. The pre-operative diagnosis was made on cytological material obtained by fine needle aspiration. The patient was a three-month-old male infant with a rapidly growing maxillary tumour mass that also involved the pterygomaxillary fossae and the floor of the orbit. In addition to the typical clinical presentation, the cytology is also distinctive showing a dual population of small neuroblastic cells and large melanin-containing epithelial cells. Histological, immunohistochemical and electron microscopic examination of the excised mass confirmed the initial diagnosis. The pre-operative distinction of this tumour from other small round cell tumours of infancy (rhabdomyosarcoma, neuroblastoma, melanoma and lymphoma), is essential in order to plan the most complete resection therefore reducing the possibilities of tumour recurrence. This tumour belongs to a field of pathology with which many otolaryngologists may not be familiar.

Melanotic neuroectodermal tumour of infancy

“…Large, epithelioid, melanin-containing cells are arranged in alveolar or tubular formations around clusters of small neuroblastic cells (15,25,26). A differential diagnosis would include other small round cell tumours occurring in infancy, such as rhabdomyosarcoma, neuroblastoma, melanoma and lymphoma.…”

Diagnostic Cytologic Features of an Epididymal Melanotic Neuroectodermal Tumor of Infancy Present in Scrotal Fluid

“…To date, the cytologic features of MNTI have been reported in only 6 cases (Table I). [9][10][11][12]19,20 In all these published reports, only direct smears were performed and evaluated cytologically; 5 were obtained from preoperative material and 1 from an intraoperative touch smear of a resected tumor. To our knowledge, there has been no documentation of MNTI involving a body fluid, nor has there been a description of the cytologic features following ThinPrep™ and/or cell block preparation.…”

“…As with the ThinPrep™ appearance described in this report, direct smears tend to be cellular. [10][11][12] In all cases, the neuroblastlike cells represent the dominant population, perhaps because they are more easily aspirated. 10 The diagnosis of MNTI in 1 other case was initially missed on FNA, possibly due to a thick smear that obscured rare pigmented cells.…”

“…In a limited number of cases, fine needle aspiration (FNA) has proven to be a simple and accurate means of diagnosing extragenital MNTI. [9][10][11][12] To date, however, descriptions of the cytologic characteristics of this tumor have been restricted to direct smear preparations obtained from aspirated lesions or from touch smears of resected tumors. To the best of our knowledge, we report for the first time a case in which an epididymal MNTI could be specifically diagnosed from aspirated hydrocele fluid processed using the ThinPrep™ system (Cytyc Corp., Boxborough, Massachusetts, U.S.A.).…”

Melanotic neuroectodermal tumour of infancy: a rare maxillary alveolar tumour

“…This should be differentiated from the other round cell tumours of infancy, i.e. rhabdomyosarcoma, neuroblastoma, melanoma, and lymphoma [6], teratoma and some of the developmental odontogenic cysts and fissural cysts. Sometimes the diagnosis is made at exploration by visualizing the characteristic melanotic pigmentation.…”