Eble JN, Sauter G., Epstein JI, Sesterhenn IA - iarc

A
B
Fig. 4.104 Papillary cystadenoma of the epididymis. A Papillary tumour with clear cell morphology. B Papillary tumour fills the lumen of an ectatic epididymal duct.
brown or yellow in colour. The cut surface
may be multicystic.
Histopathology
Microscopically, two findings are common
to all lesions: ectasia of the efferent
ducts and papillary formations. The
tumours seem to arise from the efferent
ducts, which show all degrees of ectasia
from slight dilatation to microcyst formation
{1236}. The ducts are lined by
cuboidal or columnar cells with clear or
vacuolated cytoplasm and often are filled
with a colloid-like secretion. Papillary
processes, simple or complex, arise from
the walls of the ducts and may completely
fill the cysts. Rarely, there have been
foci of a histological pattern similar to
that of the cerebellar haemangioblastoma
{1800}. By immunohistochemistry
they react with epithelial markers (Cam
5.2, AE1/AE3 and EMA) {877,2630}.
Genetics
The VHL gene has been identified and
mapped to chromosome 3p25-26.
Mutations in the VHL gene, leading to
allele loss, have been detected in sporadic
epididymal papillary cystadenoma
{877} and also in those of patients with
von Hippel-Lindau disease {206}.
Melanotic neuroectodermal
tumour
Definition
Melanin containing tumour with varying
proportions of two cells types in a cellular
fibrous stroma.
ICD-O code 9363/0
Synonyms
Retinal anlage tumour, melanotic hamartoma,
melanotic progonoma.
Epidemiology
Melanotic neuroectodermal tumour is a
rare neoplasm which typically involves
facial and skull bones. It may arise in the
epididymis where at least two dozen
examples have been reported {1073}.
Most cases affect infants under the age
of one and the oldest report is in an 8
year old.
Clinical features
Patients present with a firm mass, sometimes
associated with hydrocele. One
patient had a mild elevation of alphafetoprotein
and there is elevation in urinary
vanillylmandelic acid/homovanillic
acid levels in some cases {1073}.
Macroscopy
Macroscopically, melanotic neuroectodermal
tumours are circumscribed, round
to oval, firm epididymal masses that
measure less than 4 cm in diameter. They
A
B
Fig. 4.105 A Melanotic neuroectodermal tumour of infancy. Bland-like structures formed by melanin containing epithelioid cells. B Melanotic neuroectodermal
tumour of infancy. SYN expression.
Tumours of paratesticular structures 271