Fibrous hamartoma of infancy (FHI) is a rare, typically painless, benign tumor that develops in the subcutaneous tissues of the axilla (i.e. armpit), arms, external genitalia, or, less commonly, various other areas. It is diagnosed in children who are usually less than 2 years old or, in up to 20% of cases, develops in utero and is diagnosed in an infant at birth.The cells involved in FHI include bland fibroblasts/myofibroblasts, mature fat cells, and primitive-appearing spindle-shaped and/or star-shaped cells. The tumor was first described by R.D. Reye in 1956 who termed the disorder "subdermal fibromatous tumor of infancy" and regarded it as a reactive lesion. In a 1964 study of 30 patients, F.M. Enzinger renamed the tumor hamartoma of infancy; he regarded it to be a hamartoma (i.e. a local malformation of various normal cell types due to a systemic genetic condition) rather than a reactive lesion. However, subsequent studies have found gene mutations in FHI tumor cells and conclude that it is a true neoplasm, i.e. a growth of cells which is uncoordinated with that of the normal surrounding tissue and persists in growing abnormally even if the original trigger is removed. In 2020, the World Health Organization classified FHI in the category of benign fibroblastic and myofibroblastic tumors.Fibrous hamartoma of infancy is generally a benign tumor but may be locally aggressive, locally infiltration, and in uncommon cases produce symptoms such as tenderness. Surgical excision is the treatment of choice for FHI tumors. Presentation
The largest study to date examined 197 cases of FHI.
Subcortical dementias includes those diseases which predominantly affects the basal ganglia along with features of cognitive decline. Diseases such as progressive supranuclear palsy, Huntingtons chorea and Parkinsons disease are different in many features from the other cortical dementias like Alzheimers disease. Yet these patients present clinically with mild forgetfulness and slowed thought process along with abnormal movements and problems with motility. Clinical features
Clinically subcortical dementia usually is seen with features like slowness of mental processing, forgetfulness, impaired cognition, lack of initiative-apathy, depressive symptoms (such as anhedonia, negative thoughts, loss of self-esteem and dysphoria), loss of social skills along with extrapyramidal features like tremors and abnormal movements.In most of the patients with Huntingtons diseases the first clinical feature to appear is the change in personality. The dementia is more severe in patients with early onset of Huntingtons disease. Parkinsons disease is characterised by features of dementia in older age. The adult type "leukodystrophy" also causes subcortical dementia with prominent frontal lobe features. As a general rule the earliest symptoms in "cortical" dementia include difficulty with high-level behaviors such as memory, language, problem-solving and reasoning, mathematics and abstract thoughts – functions associated with the cerebral cortex. Such patients have prominent apraxia and agnosia. However, in "subcortical" dementia these high-level behaviours are less affected. Pathophysiology
In most common types of dementias there is widespread degeneration in the cerebral cortex – such as the plaques and neuro fibrillary tangles which are the hallmark of Alzheimers disease. In subcortical dementia, there is targeted damage to regions lying under the cortex.