Cylindroma is a benign
The tumour showed apocrine and trichoepitheliomatous
differentiation which indicated complex hair follicle (folliculo-sebaceous-apocrine).
According to recent studies immunohistochemical examination has shown
myoepithelial, apocrine, eccrine, ductal, and secretory features in both
represents an autosomal dominant disease characterized by the occurrence
of multiple cylindromas, trichoepitheliomas and (sporadically)
Clinically, the tumour usually presents as a solitary, slow growing
The multiple form
is autosomal dominantly inherited on cyld1 gene on chromosome 16.
form is also known as 'turban tumour' and may be associated with
Some of these lesions are painful.
condition is associated with trichoepitheliomas and milia.
Usually located on the
scalp, head and neck or trunk.
Histologically cylindroma is a circumscribed, non-encapsulated , dermal
tumour without attachment to the epidermis.
The lesion is composed of
numerous oval and polygonal nests arranged in an interlocking 'jigsaw-like' pattern.
There are two cell types, the peripheral cells are small
and basophilic and central cells are larger and pale stained.
Small ductal lumina may be present.
Thick PAS positive hyaline bands surround tumour
Hyaline droplets may be
present within the nests.
- Lack of lymphoid tissue in cylindroma and presence of variable number
of dendritic Langerhans cells in the tumour. These cells are CD1a
Cylindromas occasionally undergo malignant transformation.
Malignant cylindromas are characterised by islands of cells displaying marked
There is increase in mitosis and many abnormal
forms are identified.
The tumour shows invasion into the surrounding
tissue and loss of the delicate hyaline sheath.