Similar to the primary form, if secondary EMPD invades the dermis, the neoplastic cells can metastasise to the lymph nodes and in some cases, the dermis.According to the Wilkinson and Brown subclassification system, there are three subtypes for each classification. Treatment
Many chemotherapy treatments have been used, however the results are not desirable as prognosis remains to be poor. Surgery remains to be the preferred treatment of choice. Wide local excision with a 3 cm margin and intra-operative frozen sections are suggested, due to high risk of local extension despite normal appearing tissue. In cases where Paget cells have invaded the dermis and metastasized, complete removal is often unsuccessful. Recurrence is a common result. Lymphadenoectomy is often performed for infiltrative cases. In lieu of surgery, radiotherapy is also an option and is especially preferred for elderly patients or for inoperable cases where the tumour size is too large. This form of treatment is also considered as possible adjuvant therapy following excision to combat the high recurrence rate. However, there are side effects of radiotherapy, including but not limited to: vulvitis, post-radiation atrophy of mucus membranes, vaginal stenosis and sexual dysfunction.Laser therapy and photodynamic therapies were also used in the past, but it was discovered the carbon dioxide laser did not penetrate deep enough and both treatment modalities resulted in high recurrence rates.Topical chemotherapy treatments are effective, with imiquimod showing promising results. However, overall survival begins to decline 10 months following treatment with chemotherapy.
Sinus may refer to:

Anatomy
Sinus (anatomy), a sac or cavity in any organ or tissue
Paranasal sinuses, air cavities in the cranial bones, especially those near the nose, including:
Maxillary sinus, is the largest of the paranasal sinuses, under the eyes, in the maxillary bones
Frontal sinus, superior to the eyes, in the frontal bone, which forms the hard part of the forehead
Ethmoid sinus, formed from several discrete air cells within the ethmoid bone between the eyes and under the nose
Sphenoidal sinus, in the sphenoid bone at the center of the skull base under the pituitary gland
Anal sinuses, the furrows which separate the columns in the rectum
Dural venous sinuses, venous channels found between layers of dura mater in the brain
Sinus (botany), a space or indentation, usually on a leaf

Heart
Sinus node, a structure in the superior part of the right atrium
Sinus rhythm, normal beating on an ECG
Coronary sinus, a vein collecting blood from the heart
Sinus venosus, a cavity in the heart of embryos
Sinus venarum, a part of the wall of the right atrium in adults, developed from the sinus venosus

Other uses
Sinus (Chalcidice), a town of ancient Chalcidice, Greece
Sinus, gulf or bay in Latin, used in numerous toponyms in ancient writing (e.g., Sinus Magnus, Sinus Flanaticus, etc.) Sine, a trigonometric math function (Latin sinus)

See also
Sinus Medii, a small lunar mare
Sinus Successus, a lunar feature
Sines, a municipality in Alentejo, Portugal (Latin Sinus)
Sinusitis, a common ailment resulting in the inflammation of the paranasal sinuses