Cylindroma is a benign tumour in which apocrine and trichoepitheliomatous differentiation has been noted indicating complex hair follicle (folliculo-sebaceous-apocrine) rather than eccrine differentiation. 

Clinical presentation:  Clinically, the tumour usually presents as a solitary, slow growing rubbery lesion.

The multiple form is autosomal dominantly inherited on cyld1 gene on chromosome 16. This form is also known as 'turban tumour' and may be associated with spiradenoma. Some of these lesions are painful. This condition is associated with trichoepitheliomas and milia.

Site:  Usually located on the scalp, head and neck or trunk.

Microscopic features: 

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 islands. Hyaline droplets within nests.

Malignant Cylindroma:

Cylindromas occasionally undergo malignant transformation. Malignant cylindromas are characterised by islands of cells displaying marked nuclear pleomorphism. 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.

Treatment:

For solitary lesions, the treatment of choice is surgical excision. Other treatments include electrodesiccation/curettage and cryotherapy.

Multiple cylindromas usually require extensive plastic surgery that may be obviated by progressively excising a group of nodules in multiple procedures.

 D.D: include:

Other cutaneous adnexal neoplasms; Eccrine spiradenoma,  ...... 

Dr. Reza Ghaderi, Associate Professor of Dermatology