Microcystic adnexal carcinoma (MAC) is a rare sweat gland cancer, which often appears as a yellow spot or bump in the skin. It usually occurs in the neck or head, although cases have been documented in other areas of the body. Most diagnosis occur past the age of 50. Although considered an invasive cancer, metastasis rarely occurs. If the tumor spreads, it can grow and invade fat, muscles, and other types of tissue. Main treatments are wide local excision or Mohs micrographic surgery, which ensures that most, if not all, cancer cells are removed surgically. Presentation
MACs usually present as a smooth, flesh or yellow colored, slow-growing nodule or bump somewhere on the face or neck with typical development being 3–5 years. The most common location is the mouth (occurring in 74% of cases), however cases have been documented on the scalp, tongue, trunk, upper extremities, and genitals. Patients are more likely to be white, female, and middle aged or elderly, although cases have been documented in children. Although usually presenting with no visual or physical symptoms, some patients do experience numbness, paresthesia, burning, or tingling. This may be due to the invasive nature of MACs, which can burrow deep into underlying tissues and nerves in the face. MAC is very difficult to recognize and differentiate from other conditions. Specialists may suggest a series of tests including a biopsy, an MRI, or a CT scan. The average tumor size is less than 2 cm, however cases have been documented where tumor size exceeds 7.9 cm.
Signs and symptoms
A list of the common side effects broken down by frequency.Very frequent

Abnormal gastrointestinal tract
Absent pectoral muscles
Brachydactyly (Short fingers)
Dextrocardia
Diaphragmatic hernia/defect
Humerus absent/abnormal
Liver/biliary tract anomalies
Maternal diabetes
Oligodactyly/missing fingers
Radius absent/abnormal
Rhizomelic micromelia (relatively shorter proximal segment of the limbs compared to the middle and the distal segments)
Sparsity or abnormality of axillary hair on affected side
Syndactyly of fingers (webbing)
Ulna absent/abnormal
Upper limb asymmetry
Abnormal rib
Simian crease on affected sideFrequent

Hypoplastic/absent nipples
Scapula anomalyOccasional

Agenesis/hypoplasia of kidneys
Encephalocele/exencephaly
Abnormal morphology of hypothalamic-hypophyseal axis
Abnormal function of hypothalamic-hypophyseal axis
Microcephaly
Preaxial polydactyly
Ureteric anomalies (reflux/duplex system)
Vertebral segmentation anomalyIt is usually considered a unilateral condition. Some have claimed that the term can be applied in bilateral presentation, but others recommend using alternate terminology in those cases. Causes
The cause of Poland syndrome is unknown. However, an interruption of the embryonic blood supply to the arteries that lie under the collarbone (subclavian arteries) at about the 46th day of embryonic development is the prevailing theory.The subclavian arteries normally supply blood to embryonic tissues that give rise to the chest wall and hand. Variations in the site and extent of the disruption may explain the range of signs and symptoms that occur in Poland syndrome. Abnormality of an embryonic structure called the apical ectodermal ridge, which helps direct early limb development, may also be involved in this disorder. Diagnosis
Poland syndrome is usually diagnosed at birth, based upon the physical characteristics. Imaging techniques such as a CT scan may reveal the extent to which the muscles are affected. The syndrome varies in severity and as such is often not reported until puberty, when lopsided growth becomes apparent.