CLINICAL HISTORY: At 6 hours of age, an infant male born at 34 weeks gestation developed respiratory distress which persisted and increased in severity despite vigorous treatment with oxygen therapy and ventilation. He developed an intraventricular hemorrhage and died at age 2 days.

GROSS: The solid, red-brown, fleshy lungs had little aeration and a few petechiae on the pleural surfaces.

MICROSCOPIC: Within each lobule, collapsed air spaces are surrounded by expanded respiratory bronchioles and alveolar ducts lined by eosinophilic hyaline membranes. The epithelium is preserved in the larger bronchi but denuded in many of the small bronchioles. Isolated membranes contain pyknotic nuclei. Focally, the collapsed air spaces contain a small amount of cellular debris and fresh hemorrhage and some have a persistent cuboidal epithelium. The lobular septa contain dilated blood vessels and lymphatics. The small muscular arteries have a prominent medial layer.

Hyaline membrane disease;

Respiratory distress syndrome (of infancy)

Hyaline membranes, atelectasis, pulmonary immaturity

CLINICAL HISTORY: At 8 hours of age, this 35-week-gestation infant developed respiratory distress which progressed despite high therapeutic oxygen concentration and vigorous ventilation. The infant progressively deteriorated and expired at age 13 days.

GROSS: The solid, red-brown, fleshy lungs had only minimal aeration. Germinal matrix hemorrhage had progressed to intraventricular hemorrhage.

MICROSCOPIC:

In a pattern of varied degree of aeration, some lobules contain numerous expanded air spaces while others are almost diffusely collapsed. About the expanded spaces, thickened alveolar septa contain mononuclear inflammatory cells and a few spindle shaped fibroblasts. The capillaries are imbedded within the increased connective tissue. Many of the air spaces have a prominent lining of plump, low cuboidal epithelial cells. Expanded interlobular septa contain dilated lymphatics.

Bronchopulmonary dysplasia

CLINICAL HISTORY: Approximately 8 hours prior to delivery at 40 weeks gestation, fetal movements diminished and there was evidence of fetal distress. At delivery, the amniotic fluid was stained with meconium. The infant developed respiratory distress shortly after birth. Meconium tinged material was aspirated from the upper airway. The respiratory distress persisted despite vigorous resuscitation and the infant expired at 24 hours of age.

GROSS: The solid, deep red, airless lungs had, on cut section, a greenish hue within the parenchyma.

MICROSCOPIC: In the fairly well expanded air spaces, some are lined by dense, hyaline and granular membranes. Mixed with the membranes, and occasionally free in the air spaces, are a large number of squamous epithelial cells, focally mixed with aggregates of yellow-brown pigment, the residual of the meconium, and in isolated areas, with an acute inflammatory cell infiltrate. The alveoli have the thin septa and inconspicuous epithelium of a full term infant.

Meconium

CLINICAL HISTORY: This 40-week-gestation male was stillborn to a mother whose membranes had ruptured 4 days prior to delivery. Fetal heart tones had not been heard for 36 hours prior to delivery. The placenta had an acute chorioamnionitis.

GROSS: The stillborn infant was appropriately mature for 40 weeks gestation and had no gross abnormalities.

MICROSCOPIC: The air spaces have thin alveolar septa and minimal congestion of the alveolar capillaries. Many of the air spaces contain polymorphonuclear leukocytes distributed evenly without associated fibrin. Other air spaces have clusters of squamous epithelial cells from the amniotic fluid.

Pneumonia of intrauterine origin; Infected amniotic sac syndrome.

CLINICAL HISTORY: A 29-year-old mother had rupture of membranes 5 days prior to delivery.

GROSS: The membranes and the fetal surface of the placenta were yellow-green and opaque.

MICROSCOPIC: A dense purulent inflammatory cell infiltrate occupies the chorion with widespread extension into the amnion but with preservation of the amniotic epithelium.

Acute chorioamnionitis

Premature labor, prematurity, fetal infection.

Case 6 GP143

CLINICAL HISTORY: These slides are from 2 separate cases. One was a 9-day-old girl with intestinal obstruction due meconium ileus who developed respiratory distress and died at age 9 days. The second case was 7-month-old male with progressive respiratory distress who subsequently developed Candida sepsis and expired at 7 months.

GROSS: In each case, the pancreas was firm with accentuation of the lobular pattern.

MICROSCOPIC: The pancreatic acini in the 9-day-old are diffusely and uniformly dilated with intraacinar inspissation of secretion making a distinction between acini and ducts difficult. A small amount of extramedullary hematopoiesis occupies the interstitial connective tissue. Islets are abundant, preserved, and uninvolved.

In the 7-month-old, the greatly distorted architecture of the pancreas has few remaining normal acini. Most of the tissue consists of dilated ducts filled with inspissated secretion and surrounded by bland connective tissue. Islets are unaffected and lie within the connective tissue. In the adjacent duodenum, the

Cystic fibrosis

Lung, liver, gut, vas deferens

CLINICAL DATA: A 3-year-old male presented with a mass in the left upper quadrant of the abdomen.

GROSS: Pushing the kidney caudally, a large, fairly well defined tumor replaced the left adrenal, extending medially across the midline. On cut section, an ill-defined lobular pattern was interrupted by focal areas of fresh hemorrhage and calcification.

MICROSCOPIC: A thin, poorly defined fibrous capsule lies along one margin. The tumor has a poorly defined lobular pattern with incomplete cellular trabeculae. Within the lobules, cell clusters are arranged in and about an abundant, finely fibrillar stroma. For the most part, the cellular components have no well organized architectural pattern. At isolated points, clusters of cells are arranged in pseudorosettes with central fibrillar material. The cells vary somewhat in size and shape, have indistinct cytoplasmic borders, and round or oval nuclei with densely clumped chromatin. A small number of cells are in mitosis. Fresh hemorrhage is abundant in and about the tumor cells.

CLINICAL HISTORY: A 3-year-old girl presented with a mass in the left upper quadrant of the abdomen.

GROSS: A tumor measuring lOx8x6 cm. had extended from within the renal parenchyma to expand the renal capsule. On cut section a pale, gray, fleshy parenchyma was discretely demarcated from the adjacent renal structure.

MICROSCOPIC: The tumor has a characteristic trimorphic pattern with cellular and collagenous trabeculae separating cellular islands composed of irregular mixtures of solid nests and an epithelial pattern. The cellular elements vary moderately in size and shape with large nuclei and a relatively small amount of cytoplasm. Mitoses are particularly prominent.

Case 8.

Wilms tumor.