Neuroendocrine adenoma of the middle ear, middle ear adenoma, carcinoid tumour of the middle ear, amphicrine tumour of the middle ear

Definition

A tumour of the middle ear showing glandular and neuroendocrine differentiation.

Epidemiology

These tumours occur across a wide adult range.

Histopathology

The tumour architecture is most often glandular but variants include trabecular, solid, organoid or infiltrative6. The tumour is composed of cuboidal to columnar cells mixed with polygonal or plasmacytoid cells. There are round nuclei with stippled chromatin. There is no mitotic activity.

Immunohistochemistry

	Cam5.2	positive1
	AE1/AE3	positive1,5
	CK7	positive, especially in the luminal cells of glandular areas1,3
	Chromogranin	~90% of cases1,3,5
	Synaptophysin	~90% of cases1
	NSE	~90% of cases1,5
	Serotonin	~90% of cases1
	Human pancreatic polypeptide	93% of cases1,3
	CD57	1/15
	Glucagon	1/15
	ACTH	1/15
	Lysozyme	7/76
	S-100	15% of cases1
	Vimentin	1/15

Ultrastructure

There are membrane-bound neuroendocrine granules and perinuclear aggregates of intermediate filaments. The luminal cells bear microvilli.

Differential diagnosis

Ceruminous gland adenoma: lack neuroendocrine differentiation.
Adenoid cystic carcinoma: show nuclear atypia and perineural invasion. There is myoepithelial differentiation.
Middle ear paraganglioma: lacks glandular differentiation and is negative for cytokeratins.
Endolymphatic sac tumour

Prognosis

There is a recurrence rate of about 18%3. In general, they do not metastasis4, although a single case of middle ear "carcinoid" with lymph node metastases has been reported2.

References

1Perez-Ordonex B. Special tumours of the head and neck. Current Diagnostic Pathology 2003;9:366-383.

2Mooney, E. E., L. G. Dodd, et al. (1999). "Middle ear carcinoid: an indolent tumor with metastatic potential." Head Neck 21(1): 72-7.

3Torske, K. R. and L. D. Thompson (2002). "Adenoma versus carcinoid tumor of the middle ear: a study of 48 cases and review of the literature." Mod Pathol 15(5): 543-55.

4Riches, W. G. and W. H. Johnston (1982). "Primary adenomatous neoplasms of the middle ear: light and electron microscopic features of a group distinct from the ceruminomas." Am J Clin Pathol 77(2): 153-61.

5Ketabchi, S., D. Massi, et al. (2001). "Middle ear adenoma is an amphicrine tumor: why call it adenoma?" Ultrastruct Pathol 25(1): 73-8.

6Mills, S. E. and R. E. Fechner (1984). "Middle ear adenoma. A cytologically uniform neoplasm displaying a variety of architectural patterns." Am J Surg Pathol 8(9): 677-85.

This page last revised 18.2.2004.