Intermammary cleft


The intermammary cleft or intermammary sulcus or sulcus intermammarius is a surface feature of males and females that marks the division in the chest of the two breasts. The International Federation of Associations of Anatomists uses the terms "sulcus intermammarius" or "intermammary cleft" when referring to the area between the breasts. In the surgical parlance the cleavage or intermammary cleft is also known as medial difinition or medial fold of breasts. In popular usage the area is commonly referred to as a woman's cleavage. An imaginary line between the nipples that crosses the intermammary cleft, serving as a landmark for some CPR procedures, is known as the intermammary line.

Anatomy

The intermammary cleft is delineated by where each breast sits in relationship to the sternum, dividing the two breasts. Anatomically the width of a cleavage is determined at the point where the breast tissue attach to the periosteal bone membrane that covers the sternum. It is also defined by the medial attachments of the pectoralis major.
The sternal side of pectoralis major is distinct from the clavicular side, and the two are seperated by a fascial interval. The sternal side is usually more robust and has a fiber orientation that best emulates the downward pull of the subscapularis muscle.
At the midline of the breast - the intermammary cleft - a deep layer of superficial fascia is firmly attached to the pectoral fascia and the periosteum of the sternum. It forms a shelving edge that supports the breasts.
A ligamentous structure of dense Cooper's ligaments is medially inserted into the skin overlying the sternum determining the shape of the breasts and intermammary sulcus. These ligaments are helpful in supporting the breasts in an youthful disposition, and loss of elasticity or attenuation of these ligaments results in ptosis of breasts.
Lymph vessels originating at the base of the nipples can ventrally extend as far as the intermammary cleft, and to the opposite breast. The intermammary lymphatics begin as a bunch of small channels consisting of a single layer of epithelium supported by stroma. Each mesh of this network surrounds one or more of the ultimate lobules of the glands, and receives its lymph from the interacinous spaces between the acini of glands. The medial breast, along with the inferior breast, is supplied by 2nd-6th branches of intercostal nerves.

Clinical conditions

, a condition of dilated blood vessels and red to red-brown spots, is common to upper part of the cleavage, especially for those who wear sports bras or push-up bras for prolonged periods, and commonly affects fair skinned middle-aged to elderly women.
It is characterized by hypopigmentation, hyperpigmentation, telangiectasias and superficial skin atrophy, is another condition caused by long exposure to sunlight. Poikiloderma and Dermatoheliosis are treated by desquamation.
Hidradenitis suppurativa is a non-contagious chronic skin disease affects intertriginous skin of apocrine sweat gland bearing areas like inframammary fold, and intermammary sulcus. It is characterized by clusters of abscesses, epidermoid cysts, sebaceous cysts, pilonidal cysts. There is no single effective treatment for HS. The recommended treatments include antibiotics, antiandrogens, corticosteroids, ciclosporins, and TNF inhibitors.
Tinea versicolor is a condition characterized by pinhead to coin sized eruptions on the body trunk and proximal extremities, often affecting the breast cleavage as a narrow band of lesions. The majority of tinea versicolor is caused by the fungus Malassezia globosa, although Malassezia furfur is responsible for a small number of cases. Topical antifungal medications containing selenium sulfide are often recommended to treat tinea versicolor.
Intermammary cleft can get attacked by plaque type psoriasis, which can in turn can cause erythematosus. Prurigo pigmentosa is a rare skin condition of unknown cause that affects depressed places on chest and back like the intermammary area. It is characterized by the sudden onset of erythematous papules that leave a reticulated hyperpigmentation when they heal. Confluent and reticulated papillomatosis, characterized by asymptomatic, small, red to brown, slightly verrucous papules occurs on upper torso, the cleavage area and back. Granular Parakeratosis, though mostly an ailment of the armpit area, is also found on the cleavage.