Species whose cells do not have nuclei, that is, prokaryotes, may be polyploid, as seen in the large bacterium Epulopiscium fishelsoni. Hence ploidy is defined with respect to a cell. Monoploid
A monoploid has only one set of chromosomes and the term is usually only applied to cells or organisms that are normally diploid. The more general term for such organisms is haploid. Temporal terms
Neopolyploidy
A polyploid that is newly formed. Mesopolyploidy
That has become polyploid in more recent history; it is not as new as a neopolyploid and not as old as a paleopolyploid. It is a middle aged polyploid. Often this refers to whole genome duplication followed by intermediate levels of diploidization. Paleopolyploidy
Ancient genome duplications probably occurred in the evolutionary history of all life. Duplication events that occurred long ago in the history of various evolutionary lineages can be difficult to detect because of subsequent diploidization (such that a polyploid starts to behave cytogenetically as a diploid over time) as mutations and gene translations gradually make one copy of each chromosome unlike the other copy. Over time, it is also common for duplicated copies of genes to accumulate mutations and become inactive pseudogenes.In many cases, these events can be inferred only through comparing sequenced genomes. Examples of unexpected but recently confirmed ancient genome duplications include bakers yeast (Saccharomyces cerevisiae), mustard weed/thale cress (Arabidopsis thaliana), rice (Oryza sativa), and an early evolutionary ancestor of the vertebrates (which includes the human lineage) and another near the origin of the teleost fishes. Angiosperms (flowering plants) have paleopolyploidy in their ancestry.
Lung hamartomas are more common in men than in women, and may present additional difficulties in smokers. Some lung hamartomas can compress surrounding lung tissue to a degree, but this is generally not debilitating and is often asymptomatic, especially for the more common peripheral growths. They are treated, if at all, by surgical resection, with an excellent prognosis: generally, the only real danger is the inherent possibility of surgical complications. Heart
Cardiac rhabdomyomas are hamartomas composed of altered cardiac myocytes that contain large vacuoles and glycogen. They are the most common tumor of the heart in children and infants. There is a strong association between cardiac rhabdomyomas and tuberous sclerosis (characterized by hamartomas of the central nervous system, kidneys, and skin, as well as pancreatic cysts); 25-50% of patients with cardiac rhabdomyomas will have tuberous sclerosis, and up to 100% of patients with tuberous sclerosis will have cardiac masses by echocardiography. Symptoms depend on the size of the tumor, its location relative to the conduction system, and whether or not it obstructs blood flow. Symptoms are usually from congestive heart failure; in utero heart failure may occur. If patients survive infancy, their tumors may regress spontaneously; resection in symptomatic patients has good results. Nerves
Sometimes nerves can also be affected. The most common nerve to be affected by hamartoma is reported to be median nerve. Hypothalamus
One of the most troublesome hamartomas occurs on the hypothalamus.