Progressive osseous heteroplasia is a cutaneous condition characterized by cutaneous or subcutaneous ossification.According to the Progressive Osseous Heteroplasia Association:

Progressive Osseous Heteroplasia (POH) is a rare genetic condition in which the body makes extra bone in locations where bone should not form. Extra bone develops inside skin, subcutaneous tissue (fat tissue beneath the skin), muscles, tendons, and ligaments. This ”out of place extra bone formation” is commonly referred to as heterotopic ossification. In people with POH, nodules and lace-like webs of extra bone extend from the skin into the subcutaneous fat and deep connective tissues, and may cross joints. Extra bone formation near the joints may lead to stiffness, locking, and permanent immobility.”
It is associated with GNAS.A telltale symptom of POH is osteoma cutis under the skin of a newborn. It was discovered in 1994 by physician Frederick Kaplan. Diagnosis
Patients with POH have a distinctly different manifestation of symptoms than those with fibrodysplasia ossificans progressiva (FOP), though heterotopic ossification appears in both diseases. They lack the congenital abnormality of the big toe that is a diagnostic feature for FOP. People with POH also have ossification of the skin during infancy, which does not occur in FOP. Also, the pattern of ossification differs in POH, spreading in an intramembranous fashion rather than endochondral. See also
Fibrodysplasia ossificans progressiva
Punctate porokeratosis
List of cutaneous conditions
Pseudopseudohypoparathyroidism

References


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Littoral cell angioma, abbreviated LCA, and formally known as littoral cell angioma of the spleen, is a benign tumour of the spleen that arises from the cells that line the red pulp. Symptoms
LCAs most often are not clinically detectable. On occasion, their first presentation may be with splenic rupture.Most patients show no symptoms and the tumours are found incidentally. Diagnosis
Littoral cell angiomas show in CT scans. They are diagnosed by pathologists by taking a sample of the tumour via Fine Needle Aspiration or Core Needle Aspiration or from a splenectomy. Histologically, they have anastoming small vascular channels and cystic spaces with papillary projections. Treatment
The treatment for a littoral cell angioma is a splenectomy. See also
Vascular tumor

References
External links

Micrograph of a LCA (webpathology.com).