Differential Diagnosis

Summary: Diseases emerging in the neonatal period can manifest themselves only with a limited number of variants of clinical manifestations and laboratory syndromes. Despite this, the etiology of pathological conditions that occur in the neonatal period is very diverse and requires significant reserves of the theoretical base from a neonatologist and a pediatrician who is involved in clinical support and observation of patients of the neonatal period, as well as clinical experience regarding differential diagnosis. Neonatal leukemias refer to malignant processes with a rapid progressive course, which, due to the intensive development of the pathological process, can acquire an incurable character and threaten newborn’s life. Therefore, the issues of differential diagnosis of neonatal leukemias are relevant even despite the low incidence of this pathology among the cohort of neonatal patients. The presented article discusses the main clinical and laboratory syndromes of neonatal leukemia, which can occur as clinical manifestations of other diseases of the neonatal period; specifies the features, as well as the individual characteristics of each of the syndromes in different pathological conditions. Determination of combinations of clinical and laboratory syndromes in generalized infections in the neonatal period, non-malignant hematological diseases and neoplastic processes makes it possible to use these diphenifications in the diagnostic algorithm of neonatal conditions with the definition of further therapeutic tactics for managing a pediatric patient.


ALTERED MENTAL STATUS
Altered mental status includes several different states of consciousness. Delirium is confusion and irrational behavior that is sometimes accompanied by excitability. Lethargy refers to sleepiness and disinterest in the environment. Stupor or obtundation refers to a state of unconsciousness from which a child can momentarily be aroused. Coma is a prolonged state of unconsciousness.

AMENORRHEA
Amenorrhea is the absence of menses. Primary amenorrhea is defined as the absence of menarche by age 16 years in the presence of normal pubertal development or the absence of menarche by age 14 years in the absence of normal pubertal development or the absence of menarche 2 years after completion of sexual maturation. Secondary amenorrhea is defined as the absence of menstruation for at least three cycles or at least 6 months in females who have already established menstruation. It is helpful to divide the evaluation of amenorrhea into three categories: amenorrhea with normal pubertal development, amenorrhea with delayed pubertal development, and amenorrhea with abnormal genital examination findings.

BREAST MASS OR ENLARGEMENT
The differential diagnosis of a breast mass or enlargement is based on the age and sex of the child. Most breast masses in children and adolescents are benign. Obese children may sometimes appear to have breast enlargement without any breast tissue being present.

PAPULOSQUAMOUS SKIN LESIONS
A papular lesion is a solid, raised area, usually less than 1 cm in diameter, with distinct borders.

DIARRHEA
Diarrhea is an abnormally high stool volume and water content, usually associated with increased frequency of stool, although normal amounts vary dramatically among children. Typical stool volumes for infants are 5 to 10 g/kg body weight per 24 hours and 100 to 200 g per day for adults. An amount that is greater than 10 g/kg/day for an infant or greater than 200 g/day for an older child usually means diarrhea. The most common causes of altered motility and absorption are colonization or invasion by bacteria, parasites, or viruses; inflammatory processes; or drugs.

GASTROINTESTINAL BLEEDING
Many food substances, such as red dyes, fruit juices, and beets, may mimic blood and confirmation of the presence of blood by Gastroccult (vomit) or guaiac (stool) tests is essential. Upper gastrointestinal tract bleeding occurs proximal to the ligament of Treitz (between the third and fourth segments of the duodenum); lower gastrointestinal bleeding occurs distal to this ligament. Hematemesis refers to bright red or brown blood in the vomit; it is usually seen with upper gastrointestinal tract bleeding. Hematochezia is bright red, brown, or dark red blood from the rectum; it is usually caused by bleeding in the lower gastrointestinal tract, but it can be seen with brisk upper gastrointestinal bleeding. Melena is the passage of black tarry material (product of degradation of blood in the small intestine) from the rectum; it is seen in cases of upper gastrointestinal tract bleeding.

HEMATURIA
Hematuria is the presence of red blood cells in the urine. Urine dipstick detects red blood cells, hemoglobin, and myoglobin; microscopy can reveal only red blood cells. Persistent hematuria, which is the presence of more than 2 to 5 red blood cells per high-power field on at least two of three consecutive spun urine specimens obtained over a 2-month period.

JAUNDICE & HYPERBILIRUBINEMIA
Jaundice refers to the yellow color of the skin and sclera caused by hyperbilirubinemia. Bilirubin is a breakdown product of heme, derived from red blood cells. Bilirubin is carried to the liver by albumin, where it is conjugated by glucuronyl transferase to a water-soluble form. Bilirubin is then excreted into the small intestine as bile and eliminated in the stool. Hyperbilirubinemia is classified as unconjugated (indirect) hyperbilirubinemia or conjugated (direct [directly measured]) hyperbilirubinemia.

KNEE PAIN
Knee pain is acute or chronic pain in or around the knee caused by one of multiple bone, tendon, ligament, muscle, or cartilage abnormalities (see Knee Maneuvers in Charts, Formulas, Laboratory Test and Values [Section IV]). The knee is a hinge joint with bony, ligamentous, muscle, and menisci involvement. Abnormal function, acute injury, or chronic inflammation of any element may cause knee pain, which also may be referred from disorders of the hip or back.

MACROCEPHALY
Macrocephaly is a large head size, generally defined as greater than the 99th percentile for age and sex on charts of head circumference. Megalencephaly refers to large brain size and is usually determined by radiologic studies.

DIAGNOSTIC CONSIDERATIONS
Transient proteinuria occurs in up to 12% of children; only 0.5% to 5% of children have persistent proteinuria. Urinary protein excretion is considered abnormal if it exceeds 4 mg/m 2 /hr. This corresponds approximately to a 2þ or greater protein value on the urine dipstick. Sulfosalicylic acid testing (combining sulfosalicylic acid with urine) is more reliable; increasing turbidity indicates protein and is graded from 1 to 4. A ratio of urine protein to creatinine of more than 0.2 on a random urine sample suggests significant proteinuria. A 24-hour urine collection is the most accurate method of protein detection. The nephrotic range for proteinuria is defined as greater than or equal to 40 mg/m 2 /hr. Petechiae are less than 3 mm in diameter and macular. Ecchymoses are larger than 3 mm in diameter and may be macular or raised. Ecchymoses may also be tender.

SYNCOPE
Syncope or fainting refers to a transient, usually sudden, loss of consciousness caused by inadequate delivery of blood, oxygen, or glucose to the brain. Loss of consciousness lasting more than several seconds should raise suspicion for a seizure rather than a syncopal episode, and

VAGINAL BLEEDING
Vaginal bleeding is normal during the immediate neonatal period (caused by maternal hormone withdrawal) and during menstruation. Menstruation is periodic shedding of endometrial tissue and blood that accompanies puberty in girls. Menstrual bleeding can be categorized as normal or excessive. Menstrual patterns in the first 2 years after menarche (onset of menses) vary widely. A menstrual period usually is considered excessive if it lasts longer than 8 days or if more than eight pads or tampons are soaked at the peak of the cycle. Menstrual periods usually occur at intervals of 21 to 34 days.