SYPHILIS

SYPHILIS

pediagenosis    May 11, 2025   

SYPHILIS

The scrotal skin is not an uncommon site for a primary syphilitic lesion. The primary stage of syphilis is marked by the appearance of a single sore (chancre), approximately 21 days after exposure. The chancre is usually firm, round, small, and painless, lasts 3 to 6 weeks, and heals without treatment. Regardless of location, the syphilitic chancre is grossly the same (see Plate 2-23). It may occur at the penoscrotal junction with barrier contraceptives. Lesions of the scrotum, however, are much more common in later forms of syphilis, especially during early and late relapses. They appear during relapse within the first 2 years but have been observed many years later as well. Anogenital cutaneous relapse occurs in 40% of cases and scrotal lesions occur in 25% of relapsing cases.

TRAUMA TO PENIS AND URETHRA

TRAUMA TO PENIS AND URETHRA

pediagenosis    April 25, 2025   

TRAUMA TO PENIS AND URETHRA

Beneath the deep layer of Colles fascia and Buck fascia (see Plate 2-4), the paired corpora cavernosal bodies of the penis are encased in a thick tunica albuginea layer. Rupture of the corpora cavernosa is rare but is encountered from direct trauma or penile fracture from vigorous intercourse or with the use of devices. Rupture of the tunica albuginea usually includes rupture of Buck fascia see Plate 2-4), in which case the penis quickly swells as a result of extravasation of blood. Early surgical repair of the ruptured tunica albuginea may prevent thrombosis and subsequent fibrosis of the erectile tissue with consequent erectile dysfunction.

CYSTS AND CANCER OF THE SCROTUM

CYSTS AND CANCER OF THE SCROTUM

pediagenosis    April 20, 2025   

CYSTS AND CANCER OF THE SCROTUM

Sebaceous cysts (epidermoid, epidermal cysts) of the scrotal wall are not uncommon. Derived from sebaceous glands in the skin, cysts form either from over-production of secretions or as a result of obstruction of the gland outlet. These cysts, usually scrotal, appear as smooth, round cystic tumors, varying in size from a few millimeters to, in rare instances, 8 to 12 cm. Although usually solitary or few in number, the occurrence of several hundred cysts has been described. The secretions contain cholesterol crystals and degenerated epithelial cells, and the fibrous cyst capsule is lined by stratified squamous epithelium with varying degrees of atrophy. Trichilemmal cysts (pilar cysts) are clinically indistinguishable from sebaceous cysts but contain keratinous rather than sebaceous material. Regarding the cyst type, inflammation is common in the obstructed duct and can lead to infection and pain. Sebaceous cysts are not precancerous but have been known to calcify. Definitive treatment is surgical excision, best performed after infection has been quelled with antibiotics. With excision, the entire epithelial sac that lines the cyst must be removed to avoid recurrence.

Delayed Or Absent Puberty

Delayed Or Absent Puberty

pediagenosis    November 19, 2024    Comment   

Delayed Or Absent Puberty

Delayed puberty is defined as the absence of secondary sexual characteristics at age 13 in girls and 16 in boys (Chapters 11 and 12). It may result from: (i) a nonpathologic constitutional delay accompanying a growth delay; (ii) disorders of the hypothalamus or pituitary gland that result in inadequate gonadotropin secretion (hypogonadotropic hypogonadism); and (iii) disorders of the gonads that prevent adequate sex steroid secretion (hypergonadotropic hypogonadism) (Table 29.1). In girls, secondary sexual characteristics may develop without progression to menarche. This form of pubertal dysfunction and other causes of primary amenorrhoea are discussed in Chapter 30. It is important to diagnose and treat delayed or absent puberty because: (i) serious underlying conditions may be present; (ii) abnormal persistence of a child-like phenotype has profound social implications for the teenager and young adult; (iii) prolonged absence of gonadal steroid exposure leads to osteopenia, a failure of normal bone formation. Osteopenia is associated with an increased risk of fractures in weight-bearing bones such as vertebrae, hips and long bones. Treatment of delayed or absent puberty aims to correct underlying disorders. Hormone replacement with estrogen/progesterone or testosterone is often required if hypogonadism is prolonged or age-appropriate sex steroid secretion patterns cannot be restored.

INTERSEX FEMALE PSEUDOHERMAPHRODITISM

INTERSEX FEMALE PSEUDOHERMAPHRODITISM

pediagenosis    September 30, 2023   

INTERSEX: FEMALE PSEUDOHERMAPHRODITISM

A female pseudohermaphrodite is an individual with ovaries but whose external genitalia have a male appearance. This disorder of sexual development usually results from hormonal disturbances. The maternal use of androgens or high doses of certain weakly androgenic synthetic progestogens (progestins) can masculinize or virilize the fetal female external genitalia during susceptible times in pregnancy. An example of a weakly androgenic substance is the sex steroid danazol, a derivative of ethisterone (17α-ethinyl-testosterone) that is used to treat severe endometriosis. Progestogens currently used for luteal support of pregnancy in in vitro fertilization (IVF) protocols or for prevention of preterm birth are progesterone, 17α-hydroxyprogesterone caproate, and dydrogesterone. Along with clitoral enlargement (clitoromegaly), some degree of fusion of the urogenital folds can occur with exposure from the 8th through the 12th week of gestation. This can present as ambiguous genitalia at birth. If exposure occurs after the 12th gestational week, then only clitoral enlargement occurs. Females with clitoral enlargement mature normally and have normal fertility, as there is almost total regression of the genital anomaly. Surgical correction of labioscrotal fusion is also a relatively simple procedure if needed. A much rarer cause of clitoromegaly is Fraser syndrome, characterized by defects including underdevelopment of the eyes (cryptophthalmos) and linked to the gene FRAS1, which may be involved in skin epithelial morphogenesis.

Pedigree

Pedigree

pediagenosis    March 26, 2023   

Pedigree

A pedigree is a graphic method (see Figs. 6.10 and 6.11) for portraying a family history of an inherited trait. It is constructed from a carefully obtained family history and is useful for tracing the pattern of inheritance for a particular trait.

Lactation

Lactation

pediagenosis    March 21, 2023   

Lactation

Milk, which sustains mammalian infants through the first few months of life, is produced by the mammary glands (Fig. 53) under the influence of the pituitary protein hormone prolactin (Chapter 44). The glands comprise several lobules that are composed of acini (also called alveoli), similar in structure to the salivary glands and the exocrine pancreas (Chapters 37 and 40). The lobules empty into lactiferous ducts. As the ducts approach the areola (nipple), they open out to form lactiferous sinuses before narrowing again to emerge at the ampulla on the nipple. The ducts and sinuses are organized so that milk collects within them rather than flowing freely to the ampulla. They are lined by myoepithelial cells that contract to expel milk from the breast. Progesterone, oestrogen, prolactin, cortisol and growth hormone are all required to complete development of the mammary glands, which occurs during the late stages of pregnancy; for the rest of adult life the glandular tissue is rather small. Milk is formed by intense activity of the epithelial cells lining the acinus. The acinar secrete fats (triglycerides), proteins (principally casein, α-lactalbumin and lactoglobulin B) and sugars (mostly lactose) to produce an isotonic liquid that is roughly 4% fat, 1% protein and 7% sugar, with almost 100 additional trace nutrients, including many ions (including Ca²⁺), some immunoglobulins (antibodies) in the form of IgA (Chapter 10) and growth factors, such as insulin-like growth factor-1 (IGF-1) and epidermal growth factor (EGF) (Chapter 46). Colostrum, the first secretion of the mammary glands after birth, is particularly rich in protein, but has a lower sugar concentration than mature milk. It also contains high levels of antibodies (Chapter 10) that provide the infant with basic immunological protection in the first days of life. At least four secretory processes are synchronized in the epithelial cells, exocytosis, lipid synthesis and secretion, transmembrane secretion of ions and water, and transcytosis of extra-alveolar proteins such as hormones, albumin and immunoglobulins from the interstitial spaces.

Prenatal Screening and Diagnosis

Prenatal Screening and Diagnosis

pediagenosis    March 20, 2023   

Prenatal Screening and Diagnosis.

The purpose of prenatal screening and diagnosis is not just to detect fetal abnormalities but also to allay anxiety and provide assistance to prepare for a child with a specific disability. Prenatal screening cannot be used to rule out all possible fetal abnormalities. It is limited to determining whether the fetus has (or probably has) designated conditions indicated by late maternal age, family history, or well-defined risk factors.

Fertilization And The Establishment Of Pregnancy

Fertilization And The Establishment Of Pregnancy

pediagenosis    February 15, 2023    Comment   

Fertilization And The Establishment Of Pregnancy.

The egg

At ovulation, the egg is arrested in metaphase of the second meiotic division (Chapter 4). It is surrounded by a proteinaceous sphere called the zona pellucida. Those granulosa cells that adhered to the surface of the zona pellucida and were expelled with the egg from the ovary remain attached as the cumulus. Sperm that fertilize the egg must first negotiate these surrounding layers before they can penetrate the egg cell membrane. The oocyte will remain viable for at least 6–24 h once ovulated.

Steroid Hormone Biosynthesis

Steroid Hormone Biosynthesis

pediagenosis    February 14, 2023   

Steroid Hormone Biosynthesis.

Cholesterol and the steroid production pathway Cholesterol is the building block of steroid hormones. All steroid-producing organs with the exception of the placenta can synthesize cholesterol from acetate. Under most circumstances, however, local synthesis cannot meet demand and circulating cholesterol must be used. The major carriers of cholesterol in the bloodstream are the low density lipoproteins (LDLs). LDL is removed from the blood by steroidogenic cells using cell surface receptors that recognize specific surface proteins on LDL called apoproteins. Once in the cell, cholesterol is carried through a sequence of enzymatic changes to produce a final product that belongs to one of the major classes of steroid hormones: progestins, androgens and estrogens (sex), glucocorticoids (sugar) and mineralocorticoids (salt). All steroid-producing tissues use a common sequence of precursor molecules and enzymes (Fig. 2.1). Tissue specificity is conferred by the presence or absence of specific enzymes in the sequence. For instance, the gonads differ from the adrenal glands in that ovaries and testes do not express the 21-hydroxylase or 11β-hydroxylase enzymes that are necessary to produce corticosteroids. Therefore, the gonads only produce three classes of steroids: progestins, androgens and estrogens.

Reproductive Genetics

Reproductive Genetics

pediagenosis    February 02, 2023   

Reproductive Genetics

Chromosomes

Human chromosomes are complex structures consisting of deoxyribonucleic acid (DNA), ribonucleic acid (RNA) and protein. Each single helix of DNA is bound at each end with a telomere and has a centromere somewhere along the length of the chromosome. The telomere protects the ends of the chromosome during DNA replication. Telomere shortening is associated with aging. The centromere is the site at which the mitotic spindle will attach and is necessary for proper segregation of chromosomes during cell division. The centromere divides the chromosome into two arms, identified as p (petit) for the short arm and q for the long arm. The centromere can be positioned anywhere along the arm of the chromosome and its location has been used to group like chromosomes together as central (metacentric), distal (acrocentric) or others (submetacentric). The length of the chromosome plus the position of its centromere are used to identify individual chromosomes within the 22 pairs of autosomes and one pair of sex chromosomes. Chromosomes are numbered in descending order of size; 1 is the largest. The only exception to this rule is chromosomes 21 and 22; 22 is larger than 21. Because of the historical convention of associating Down syndrome with trisomy 21, this chromosome pair was not renamed when the size difference became apparent.

Musculoskeletal System: Limbs

Musculoskeletal System: Limbs

pediagenosis    January 31, 2023    Comment   

Musculoskeletal System: Limbs

Time period: week 4 to adult

Introduction

Limb development has been studied in great detail, although it is not entirely clear how it is initiated. The mechanisms by which the cells of the early limb are organised, and the fates of those cells, have been explored for decades, as aberrations of these processes cause gross limb abnormalities.

Skeletal System

Skeletal System

pediagenosis    January 31, 2023    Comment   

Skeletal System

Time period: day 27 to birth

Introduction

Cells for the developing skeleton come from a variety of sources. We have described the development of the somites, and the subdivision of the sclerotome (see Chapter 22). Those cells are joined by contributions from the somatic mesoderm and migrating neural crest cells.

Development of the skeleton can be split into two parts: the axial skeleton consisting of the cranium, vertebral column, ribs and sternum; and the appendicular skeleton of the limbs.

PUERPERAL INFECTION

PUERPERAL INFECTION

pediagenosis    December 01, 2021    Comment   

PUERPERAL INFECTION

Puerperal infection generally refers to an infection of the genital tract in the postpartum period. For centuries, puerperal infection was the leading cause of maternal death, though this has changed dramatically with the advent of antibiotics. Maternal death rates associated with infection account for approximately 0.6 maternal deaths per 100,000 live births. Endometritis is the most common form of postpartum infection, though other sources of postpartum infections include postsurgical wound infections, perineal cellulitis, mastitis, respiratory complications from anesthesia or under-lying pulmonary disease such as asthma or obstructive lung disease, retained products of conception, urinary tract infections, and septic pelvic phlebitis. Overall, postpartum infection is estimated to affect 1% to 3% of normal vaginal deliveries, 5% to 15% of scheduled caesarean deliveries, and 15% to 20% of unscheduled caesarean deliveries.

The organisms responsible for the vast majority of puerperal infections are the anaerobic and aerobic nonhemolytic varieties of streptococci. These organisms are usually present in the birth canal, becoming pathogenic when carried to the uterine cavity during or after delivery.

ERYTHROBLASTOSIS FETALIS (RH SENSITIZATION)

ERYTHROBLASTOSIS FETALIS (RH SENSITIZATION)

pediagenosis    December 01, 2021    Comment   

ERYTHROBLASTOSIS FETALIS (RH SENSITIZATION)

Isoimmunization of the mother to any dissimilar fetal blood group not possessed by the mother is possible. Historically the most common example is the Rh (D) factor. Erythroblastosis fetalis (hemolytic disease of the newborn) is characterized by sustained destruction of the fetal erythrocytes by specific maternal antibodies (IgG), which cross the placenta to the fetus. What was once a common cause for fetal death has largely been eradicated by prophylactic maternal administration of immune globulin against the Rh (D) factor to those at risk.

Human red blood cells contain a complex group of inherited antigens, one of which is the Rhesus CDE antigen system. The genes for the CDE blood groups are inherited separately from the ABO groups and are located on the short arm of chromosome 1. One of the more important antigens of this group is Rh (D) factor. About 85% of all individuals are Rh (D)-positive whereas 15% are Rh (D)-negative. Any process that exposes the woman to blood carrying the D antigen including blood transfusion, miscarriage, ectopic or normal pregnancy, trauma during pregnancy, amnio-centesis, and others can result in anti-Rh agglutinins being formed. The IgG antibodies can cross the placenta into the fetal circulation and result in the destruction of the Rh-positive fetal blood. Other isoimmunizations (most frequently Kell, or Duffy antigens) can also result in similar effects on the fetus.

SYPHILIS

SYPHILIS

pediagenosis    December 01, 2021    Comment   

SYPHILIS

In many geographical regions, syphilis is still the most common cause of fetal death in the later months of gestation. In many developed countries, the number of primary and secondary syphilis cases rose dramatically during the late 1980s and early 1990s (peak 1991) as a result of illicit drug use and the exchange of drugs for sex. Although rare in developed countries, the incidence of syphilis is high and increasing in many developing countries (and in the transitional economies of Eastern Europe and the former Soviet Union), particularly where HIV/AIDS is common. Of infants born to mothers with primary or secondary syphilis, up to 50% will be premature, stillborn, or die in the neonatal period. In many cases, surviving children are born with congenital defects some of which may not be apparent for years.

The fetus is infected through the placenta from the mother. When an infected fetus is born alive, the symptomatology of congenital syphilis soon becomes manifest. While appropriate treatment of the mother can prevent congenital syphilis, the inability to effectively identify infected patients and get them to undergo treatment continues to present a challenge to reducing the incidence of syphilitic complications. Screening in the first trimester with nontreponemal tests such as rapid plasma reagin or Venereal Disease Research Laboratory test combined with confirmation of reactive individuals with treponemal tests such as the fluorescent treponemal antibody absorption (FTA-ABS) assay is a cost-effective strategy. Those at risk should be retested in the third trimester.

INTRAUTERINE GROWTH RESTRICTION

INTRAUTERINE GROWTH RESTRICTION

pediagenosis    December 01, 2021    Comment   

INTRAUTERINE GROWTH RESTRICTION

Symmetric or asymmetric reduction in the size and weight of the growing fetus in utero, compared with that expected for a fetus of comparable gestational age, constitutes intrauterine growth restriction. This reduced growth may occur for many reasons, but most occurrences represent signs of significant risk of fetal death or jeopardy to the fetus. Some authors advocate identifying fetuses with growth between the 10th and 20th percentiles as suffering “diminished” growth and at intermediate risk for complications. Problems of consistent definition make estimates of the true prevalence of growth restriction difficult, but by most definitions it occurs in 5% to 10% of pregnancies.

The risk of intrauterine growth restriction increases with the presence of maternal conditions that reduce placental perfusion (hypertension, preeclampsia, drug use, smoking) or those that reduce the nutrients available to the fetus (chronic renal disease, poor nutrition, inflammatory bowel disease). Abnormalities of placental implantation or function can result in significant reduction in nutrient flow to the fetus. The risk is also higher at the extremes of maternal age: for women less than 15 years old the rate of low birth weight is 13.6% compared with 7.3% for women between 25 and 29 years old. When multiple gestations are excluded, the rate for women older than 45 years is greater than 20%. Multiple pregnancies, especially higher order multiples, are at increased risk for growth restrictions. In most cases of growth restriction, no specific cause is identified.

CAUSES OF DECREASED MATERNAL CIRCULATION

CAUSES OF DECREASED MATERNAL CIRCULATION

pediagenosis    December 01, 2021    Comment   

CAUSES OF DECREASED MATERNAL CIRCULATION

Various pathologic conditions may impede the maternal circulation to the placenta. They can be grouped as follows:

1. Diseases of the uterine vessels: (a) acute atherosis, (b) arteriolar sclerosis associated with essential hypertension, and (c) inflammation (angiitis) associated with chorioamnionitis.

2. Premature separation of the placenta associated with retroplacental hemorrhage or inflammatory exudation.

3.  Conditions that may cause an increase in intra-uterine pressure: (a) multiple pregnancy, (b) macrosomia, (c) polyhydramnios, and (d) hydatidiform mole.

4.   Extensive thrombosis of the intervillous space or of the marginal sinus.

5.   Death of the mother.

The most common cause of placental infarcts in cases of preeclampsia have been found to be acute atherosis of the decidual vessels. This lesion is manifested microscopically as a deposition of lipids, in the intima of decidual arterioles and endometrial arteriovenous lakes. Part of the material is doubly refractive under polarized light and occurs both extracellularly and inside lipophages. The lesions closely resemble acute fulminating atherosis in other settings. The process leads to marked intimal thickening and vascular occlusion. The lesions occur in the decidua vera, as well as in the basalis, but they do not involve to a comparable degree the vessels of the myometrium or other tissues in the body. Fat stains have not revealed the lesion in fetal vessels. Contiguous trophoblastic tissue seems to be a necessary factor in its pathogenesis. The lesions regress promptly after delivery. The cause of this condition is still unknown.

PREECLAMPSIA IV-PLACENTAL INFARCTS

PREECLAMPSIA IV-PLACENTAL INFARCTS

pediagenosis    December 01, 2021    Comment   

PREECLAMPSIA IV-PLACENTAL INFARCTS

Because preeclampsia is a condition peculiar to pregnancy, and because delivery usually results in the rapid regression of the signs, symptoms, and pathologic lesions, it would seem reasonable to believe that the contents of the gravid uterus either may be the source of the vasoconstrictor factor or may play an important role in leading to the production of that factor elsewhere in the body. The fetus is not a required factor, because severe preeclampsia occasionally accompanies hydatidiform mole. Therefore, the trophoblastic tissue or the gravid endometrium would seem to be incriminated. Despite this, there are no micro- or macroscopic placental lesions that are pathognomonic for preeclampsia.

Pathologic studies have revealed close correlation between the occurrence of preeclampsia and conditions that are prone to cause a decrease in the maternal circulation to the placenta, to the decidua, or to both of these tissues. Obstruction of the maternal blood flow to one or more placental cotyledons causes true infarction of the involved areas. Unfortunately, the term infarct has often been used for a wide variety of nodular lesions in the placenta, and conflicting opinions have been expressed concerning the association of such lesions with preeclampsia.

PREECLAMPSIA III—VISCERAL LESIONS IN PREECLAMPSIA AND ECLAMPSIA

PREECLAMPSIA III—VISCERAL LESIONS IN PREECLAMPSIA AND ECLAMPSIA

pediagenosis    December 01, 2021    Comment   

PREECLAMPSIA III—VISCERAL LESIONS IN PREECLAMPSIA AND ECLAMPSIA

Although preeclampsia and eclampsia are differentiated, depending upon whether or not the patient has had a convulsion, the pathology of the two is essentially the same. Characteristic lesions frequently appear in the liver, kidneys, and brain, but they are inconstant in occurrence and may be absent even in severe cases with convulsions. Therefore, they cannot be considered primary lesions but are probably the sequelae of the three constantly present features of the disease, namely, vasoconstriction, hypertension, and fluid retention.

In typical cases, the liver is swollen and mottled with small hemorrhages. Microscopically, the sinusoids around the smaller portal areas are plugged with fibrinoid material and surrounded by foci of hemorrhage and necrotic liver cells. Occasionally, midzonal necrosis is seen, but serial sections usually reveal continuity with larger periportal lesions. The condition may be wide- spread or may involve only a few subcapsular lobules.