Common symptoms include cough, dyspnea, weight loss, and debility. Over 70% of patients with small-cell carcinoma present with metastatic disease; common sites include liver, adrenals, bone, and brain.Due to its high grade neuroendocrine nature, small-cell carcinomas can produce ectopic hormones, including adrenocorticotropic hormone (ACTH) and anti-diuretic hormone (ADH). Ectopic production of large amounts of ADH leads to syndrome of inappropriate antidiuretic hormone hypersecretion (SIADH).Lambert–Eaton myasthenic syndrome (LEMS) is a well-known paraneoplastic condition linked to small-cell carcinoma. Small-cell lung cancer
When associated with the lung, it is sometimes called "oat cell carcinoma" due to the flat cell shape and scanty cytoplasm. Caution is required when diagnosing SCLC because small cell mesothelioma – an extremely rare subtype of lung cancer – can be mistaken for small cell lung cancer.It is thought to originate from neuroendocrine cells (APUD cells) in the bronchus called Feyrter cells (named for Friedrich Feyrter). Hence, they express a variety of neuroendocrine markers, and may lead to ectopic production of hormones like ADH and ACTH that may result in paraneoplastic syndromes and Cushings syndrome. Approximately half of all individuals diagnosed with Lambert–Eaton myasthenic syndrome (LEMS) will eventually be found to have a small-cell carcinoma of the lung.Small-cell carcinoma is most often more rapidly and widely metastatic than non-small-cell lung carcinoma (and hence staged differently). There is usually early involvement of the hilar and mediastinal lymph nodes. The mechanisms of its metastatic progression are not well-understood.
Phakomatosis pigmentokeratotica is a rare neurocutanous condition  characterized by the combination of an organoid sebaceous nevus and speckled lentiginous nevus. : 634–5 : 776  It is an unusual variant of  epidermal naevus syndrome. It was first described by Happle et al. It is often associated with neurological or skeletal anomalies such as hemiatrophy, dysaesthesia and hyperhidrosis in a segmental pattern, mild mental retardation, seizures, deafness, ptosis and strabismus. See also
Skin lesion
List of cutaneous conditions associated with increased risk of nonmelanoma skin cancer

References


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