Hematology + Bone Marrow
General Findings in Hematologic Conditions
Pallor
Pallor, the loss of normal color of the skin or mucous membranes, is most visible on the face, conjunctivae, nail beds, and palms of of the hands. The phenomenon of pallor occurs due to a lowered hemoglobin content visualized in these areas where the microvascular bed can be seen through the skin. There are many causes, including emotion, hemorrhage, drugs, cold, shock, and anemia.
Flushing
Flushing is due to dilation of the cutaneous blood vessels. It is mediated by the sympathetic nervous system and is often associated with sweating. Rosacea is associated with flushing, and alcohol use can also induce flushing.
Cyanosis
In cyanosis, the skin and mucous membranes develop a blue/purple hue. It is most notable in the periphery, in sites such as the lips, ears, and nail beds. Cyanosis is caused by a reduced oxygen supply to these tissues, due to low levels of hemoglobin in the capillary beds. Peripheral cyanosis is typically associated with vasoconstriction, while central cyanosis (lingual and sublingual region) is associated with reduced hemoglobin in the bloodstream. Detecting cyanosis can be difficult, as darker skin pigment and increased skin thickness mask this finding. Both disorders of abnormal hemoglobin and disorders of deoxygenated hemoglobin (include heart and lung problems) can cause cyanosis.
Jaundice
Jaundice is a yellow discoloration of the skin, as a result of elevated levels of bilirubin. The bile pigment bilirubin directly stains the skin. A finding of jaundice should raise suspicion of a problem with bilirubin clearance, increased production due to a hepatobiliary disorder, or hemolytic anemia (destruction of red blood cells). In neonates, hyperbilirubinemia is a concern due to the risk of neurological damage.
Pallor, the loss of normal color of the skin or mucous membranes, is most visible on the face, conjunctivae, nail beds, and palms of of the hands. The phenomenon of pallor occurs due to a lowered hemoglobin content visualized in these areas where the microvascular bed can be seen through the skin. There are many causes, including emotion, hemorrhage, drugs, cold, shock, and anemia.
Flushing
Flushing is due to dilation of the cutaneous blood vessels. It is mediated by the sympathetic nervous system and is often associated with sweating. Rosacea is associated with flushing, and alcohol use can also induce flushing.
Cyanosis
In cyanosis, the skin and mucous membranes develop a blue/purple hue. It is most notable in the periphery, in sites such as the lips, ears, and nail beds. Cyanosis is caused by a reduced oxygen supply to these tissues, due to low levels of hemoglobin in the capillary beds. Peripheral cyanosis is typically associated with vasoconstriction, while central cyanosis (lingual and sublingual region) is associated with reduced hemoglobin in the bloodstream. Detecting cyanosis can be difficult, as darker skin pigment and increased skin thickness mask this finding. Both disorders of abnormal hemoglobin and disorders of deoxygenated hemoglobin (include heart and lung problems) can cause cyanosis.
Jaundice
Jaundice is a yellow discoloration of the skin, as a result of elevated levels of bilirubin. The bile pigment bilirubin directly stains the skin. A finding of jaundice should raise suspicion of a problem with bilirubin clearance, increased production due to a hepatobiliary disorder, or hemolytic anemia (destruction of red blood cells). In neonates, hyperbilirubinemia is a concern due to the risk of neurological damage.
Thrombocytopenic Purpura
Petechiae of ITP - National Institutes of Health
Idiopathic Thrombocytopenic Purpura
ITP is typically associated with petechiae on the lower extremities, along with epistaxis, menorrhagia, and gingival bleeding. Most common in children, ITP is caused by autoantibodies to platelet surface proteins, including glycoproteins IIb/IIIa and Ib. Patients are usually asymptomatic, and present with petechiae and ecchymoses. Oral blisters and GI bleeding can also be associated with this disease.
Thrombotic Thrombocytopenic Purpura
TTP is more common in adults, as opposed to the pediatric hemolytic-uremic syndrome (HUS). This syndrome is caused by a defect in Von Willebrand factor, resulting in platelet-fibrin aggregates that can block small vessels. TTP can be a complication of pregnancy, cancer, drugs, bone marrow transplant, and autoimmune diseases. Lab values show increased LDH, and schistocytes, helmet cells, and megakaryocytes on blood smear.
ITP is typically associated with petechiae on the lower extremities, along with epistaxis, menorrhagia, and gingival bleeding. Most common in children, ITP is caused by autoantibodies to platelet surface proteins, including glycoproteins IIb/IIIa and Ib. Patients are usually asymptomatic, and present with petechiae and ecchymoses. Oral blisters and GI bleeding can also be associated with this disease.
Thrombotic Thrombocytopenic Purpura
TTP is more common in adults, as opposed to the pediatric hemolytic-uremic syndrome (HUS). This syndrome is caused by a defect in Von Willebrand factor, resulting in platelet-fibrin aggregates that can block small vessels. TTP can be a complication of pregnancy, cancer, drugs, bone marrow transplant, and autoimmune diseases. Lab values show increased LDH, and schistocytes, helmet cells, and megakaryocytes on blood smear.
Disseminated Intravascular Coagulation (DIC)
Purpura Fulminans - Fitzpatrick's Dermatology
DIC is a syndrome in which coagulation cascades are activated leading to the deposition of fibrin in the small blood vessels. Coagulation factors are then consumed and exhausted. Due to microvascular thrombosis, organ dysfunction is associated with DIC. It is not a disease, but rather a syndrome secondary to an underlying disorder, such as sepsis, trauma, malignancy, or toxic/immunological reactions.
Purpura Fulminans
In this disorder, large areas of skin develop blue-black hemorrhagic necrosis. This is due to DIC and its associated blood vessel microthombi and vasculitis of cutaneous tissue. The distribution of skin lesions varies with the clinical setting.
There are three primary causes of purpura fulminans. Acute sepsis in the presence of a superinfection can lead to DIC and purpura fulminans. It is most commonly associated with meningococcemia, but can occur with many gram-positive and gram-negative bacteria. A patient's hypotensive state due to sepsis further contributes to the lack of perfusion of the skin, particularly in the extremities. Second, purpura fulminans can occur in a patch distribution within 10 days of a preceeding illness, such as vericella or scarlet fever. Finally, it can be associated with a protein C deficiency in neonates, which may also develop intravascular thrombosis and abdominal wall gangrene.
Purpura Fulminans
In this disorder, large areas of skin develop blue-black hemorrhagic necrosis. This is due to DIC and its associated blood vessel microthombi and vasculitis of cutaneous tissue. The distribution of skin lesions varies with the clinical setting.
There are three primary causes of purpura fulminans. Acute sepsis in the presence of a superinfection can lead to DIC and purpura fulminans. It is most commonly associated with meningococcemia, but can occur with many gram-positive and gram-negative bacteria. A patient's hypotensive state due to sepsis further contributes to the lack of perfusion of the skin, particularly in the extremities. Second, purpura fulminans can occur in a patch distribution within 10 days of a preceeding illness, such as vericella or scarlet fever. Finally, it can be associated with a protein C deficiency in neonates, which may also develop intravascular thrombosis and abdominal wall gangrene.
Cutaneous Lymphoma
Patches and Plaques of Cutaneous T-Cell Lymphoma
Primary cutanous lymphoma has a different clinical presentation and prognosis than similar lymphomas located in the lymph nodes. Of lymphomas that occur outside the lymph nodes, cutaneous lymphoma is second in incidence, topped only by gastrointestinal lymphomas. It is caused by a pathologic clonal proliferation of B or T cells in the skin. The most common variety is the primary cutaneous T-cell lymphoma mycosis fungoides, or MF. It manifests as a plaque, patch, or tumor, but many different types of lesions are often present at the same time. Classically, it is found in non-sun exposed areas, and may present with pruritis and a past history of chronic dermatitis. Lesions found on the body progress through stages, moving from patch --> plaque --> tumor over a period of months to years. The prognosis of cutaneous lymphoma limited to the skin is very good with treatment, with 5-year survival rates of 80-100 percent.
Langerhan's Cell Histiocytosis
May be removed due to relevancy
Mastocytosis
May be removed due to relevancy