Diseases

Medullary thyroid cancer

Medullary thyroid cancer (MTC) is a form of thyroid carcinoma, which grows from specialized thyroid cells called parafollicular cells, or C-cells that make a hormone called calcitonin. Calcitonin helps control bone formation and blood calcium levels.

When MTC coexists with tumors of the parathyroid gland and medullary component of the adrenal glands (pheochromocytoma), it is called multiple endocrine neoplasia type 2 (MEN2).

Approximately 25% the cancer develops in families. Familial MTC syndromes include MEN 2A, which is the most common; MEN 2B; and familial non-MEN syndromes.

Medulloblastoma

Medulloblastoma (muh-dul-o-blas-TOE-muh) is a cancerous (malignant) brain tumor that starts in the lower back part of the brain, called the cerebellum. The cerebellum is involved in muscle coordination, balance and movement.

Medulloblastoma tends to spread through cerebrospinal fluid (CSF) — the fluid that surrounds and protects your brain and spinal cord — to other areas around the brain and spinal cord. This tumor rarely spreads to other areas of the body.

Medulloblastoma is a type of embryonal tumor — a tumor that starts in the fetal (embryonic) cells in the brain. Based on different types of gene mutations, there are at least four subtypes of medulloblastoma. Though medulloblastoma is not inherited, syndromes such as Gorlin’s syndrome or Turcot’s syndrome might increase the risk of medulloblastoma.

Signs and symptoms of medulloblastoma may include headaches, nausea, vomiting, tiredness, dizziness, double vision, poor coordination, unsteady walk and other concerns. These symptoms may be related to the tumor itself or be due to the buildup of pressure within the brain.

Medulloblastoma can occur at any age, but most often occurs in young children. Though medulloblastoma is rare, it’s the most common cancerous brain tumor in children. Children need to be seen at a center that has a team of pediatric specialists with expertise and experience in pediatric brain tumors, with access to the latest technology and treatments for children.

The cumulative relative survival rate for all age groups and histology follow-up was 60%, 52%, and 32% at 5 years, 10 years, and 20 years, respectively, with children doing better than adults.

Megacystis microcolon intestinal hypoperistalsis syndrome

Megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIH syndrome, Berdon syndrome), is an autosomal recessive genetic disorder affecting newborns. It is more prevalent in females, and is characterized by constipation and urinary retention, microcolon, giant bladder (megacystis), intestinal hypoperistalis, hydronephrosis, and dilated small bowel. The pathological findings consist of an abundance of ganglion cells in both dilated and narrow areas of the intestine. It is a familial disturbance of unknown aetiology.

Megaduodenum

Megaduodenum: A rare condition where the duodenum is dilated and the muscles don't function normally which affects the movement of digestive waste material through the intestines. The symptoms of the condition are similar to that caused by an intestinal obstruction.

Megaepiphyseal dwarfism

Megaepiphyseal dwarfism (medical condition): A rare genetic disorder where abnormal bone growth causes hearing loss, skeletal abnormalities and characteristic facial features.

Megalencephaly cutis marmorata telangiectatica congenita

Megalencephaly - cutis marmorata telangiectatica congenita: A very rare syndrome characterized mainly by an enlarged brain, neurological abnormalities and a blood vessel abnormality that gives the skin a marbled appearance.

Megaloblastic anemia

Megaloblastic (pernicious) anemia is a rare disorder in which the body does not absorb enough vitamin B12 from the digestive tract, resulting in an inadequate amount of red blood cells (RBCs) produced.

Megalocornea mental retardation syndrome

Megalocornea mental retardation syndrome: A very rare genetic disorder characterized by reduced muscle tone from birth, mental retardation to varying degrees and eye abnormalities. The type and severity of symptoms is variable.

Megarbane syndrome

Megarbane syndrome: A very rare disorder characterized by short stature, loose joints, hernias, facial abnormalities and severe psychomotor retardation.

Mehes syndrome

Mehes syndrome: A very rare syndrome characterized mainly by delayed speech, an asymmetrical face, crossed eyes and ear lobe creases.

Mehta Lewis Patton syndrome

Mehta Lewis Patton syndrome (medical condition): A rare birth syndrome characterized by heart disease, droopy eyelids, missing teeth and premature fusion of skull bones.

Meier Rotschild syndrome

Meier-Rotschild syndrome: A rare disorder characterized mainly by short stature, small ears and absent kneecaps.

Meige syndrome

Meige's syndrome is a type of dystonia. It is also known as oral facial dystonia. It is actually a combination of two forms of dystonia, blepharospasm and oromandibular dystonia (OMD).

Meinecke Pepper syndrome

Meinecke pepper syndrome (medical condition): A very rare syndrome characterized mainly by short arms, facial anomalies and various other abnormalities.

Meinecke syndrome

Meinecke syndrome: A very rare syndrome characterized mainly by mental retardation and short broad thumbs.

Melanoma astrocytoma syndrome

Melanoma - astrocytoma syndrome: A rare syndrome characterized by the association of a melanoma with a type of brain tumor called an astrocytoma. The exact symptoms may vary depending on the exact location of the brain tumor. More detailed inform

Melanoma of the choroid

Melanoma of the choroid: A type of eye cancer that occurs in the pigment-producing cells of the choroid which is a layer beneath the retina consisting mainly of blood vessels.

Melanoma of the ciliary body

Malignant melanoma that originates in the ciliary body is termed, "ciliary body melanoma." The ciliary body is located immediately behind the iris and in front of the choroid. Therefore, it is hidden behind the iris. It is responsible for making the aqueous fluid that fills the front of the eye. The ciliary body is highly vascular and contains the melanocytes from which melanomas can grow. Compared to iris and choroidal melanoma, ciliary body melanoma is the most difficult to find.

Melanoma of the iris

The iris is the colored part of the eye. It is made up of two layers. The outer "stroma" can be blue, hazel, green or brown. The back layer (the iris pigment epithelium) is always brown. Tumors can grow within and behind the iris. Though most iris tumors are cysts or nevi, malignant melanomas can also occur in the iris.

Meleda Disease

Meleda Disease: A very rare inherited skin disorder primarily involving dry thick skin patches that develop on the palms of hands and soles of feet. The type and severity of symptoms is variable.

Melioidosis

Melioidosis is an infectious disease caused by a gram-negative bacterium, Burkholderia pseudomallei, found in soil and water. It is of public health importance in endemic areas, particularly in Thailand and northern Australia. It exists in acute and chronic forms. Signs and symptoms may include pain in chest, bones, or joints; cough; skin infections, lung nodules and pneumonia.

B. pseudomallei was previously classed as part of the Pseudomonas genus and until 1992, it was known as Pseudomonas pseudomallei. It is phylogenetically related closely to Burkholderia mallei which causes glanders, an infection primarily of horses, donkeys, and mules. The name melioidosis is derived from the Greek melis (μηλις) meaning "a distemper of asses" with the suffixes -oid meaning "similar to" and -osis meaning "a condition", that is, a condition similar to glanders.

Melkersson-Rosenthal syndrome

Melkersson-Rosenthal syndrome is a rare neurological disorder characterized by recurring facial paralysis, swelling of the face and lips (usually the upper lip), and the development of folds and furrows in the tongue. Onset is in childhood or early adolescence. After recurrent attacks (ranging from days to years in between), swelling may persist and increase, eventually becoming permanent. The lip may become hard, cracked, and fissured with a reddish-brown discoloration. The cause of Melkersson-Rosenthal syndrome is unknown, but there may be a genetic predisposition. It can be symptomatic of Crohn's disease or sarcoidosis.

Melnick-Needles syndrome

This rare genetic syndrome is best described in females, with a small number of severely affected males also reported.

Melorheostosis

Melorheostosis: A rare bone condition that usually begins in childhood characterized by thickening of the bones (sclerosis) of a limb. Pain is frequent in the involved limb. The affected bone can have the appearance of "dripping candle wax" when visualized with X-ray imaging.