Selected Photomicrographs

A. Seminiferous tubule (Figure 25-3; see I)

Figure 25-3. Light micrograph of seminiferous tubules within the testes. The seminiferous tubules contain spennatogonia (/), primary spermatocytes (2) , secondary spermatocytes (3), early spermatids (4), late spermatids (5), and Sertoli cells (6). In addition, the three stages of spermatogenesis (i.e., spennatocytogenesis, meio-sis, and spermiogenesis) are indicated by the brackets (correlate with Table 25-1). The level of the blood-testis barrier is indicated by the dotted line.

Figure 25-3. Light micrograph of seminiferous tubules within the testes. The seminiferous tubules contain spennatogonia (/), primary spermatocytes (2) , secondary spermatocytes (3), early spermatids (4), late spermatids (5), and Sertoli cells (6). In addition, the three stages of spermatogenesis (i.e., spennatocytogenesis, meio-sis, and spermiogenesis) are indicated by the brackets (correlate with Table 25-1). The level of the blood-testis barrier is indicated by the dotted line.

B. Leydig cells (Figure 25-4; see IV)

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Figure 25-4. (A) Light micrograph of Leydig cells (Ley) found in the connective tissue between the seminiferous tubules. (B) Electron micrograph of Leydig cells. Smooth endoplasmic reticulum (S), mitochondria with tubular cristae (M), and lipid droplets (arrows) are typically found in a steroid-secreting cell. CR = crystals of Reinke. (Reprinted with permission from Kerr JB: Ultrastructure of the seminiferous epithelium and intertubu-lar tissue of the human testis. J Electron Microsc Tech 19(2): 215-240, 1991. © 1991 Wiley-Liss. Reprinted by permission of Wiley-Liss, Inc., a subsidiary of John Wiley & Sons, Inc.)

C. Seminoma (Figure 25-5)

Figure 25-5. Light micrograph of seminoma. Approximately 95% of testicular neoplasms arise from germ cells. Almost all germ cell neoplasms involve the isochromosome of the short arm of chromosome 12 |i(12p)], which is virtually diagnostic. Seminoma is the most common type of germ cell neoplasm. (A) Low-power light micrograph of a seminoma showing normal testicular tissue at the periphery (Nor) with typical seminiferous tubules and seminoma (Sem). (B) High magnification showing normal testicular tissue at the periphery with typical seminiferous tubules. (C) High magnification of a seminoma, which consists of clusters of moderately sized round cells with large centrally located nuclei with prominent nucleoli (outlined areas). Mitotic figures can be observed (arrows). The cell clusters are separated by fibrous cords (arrowheads in A). The fibrous cords are heavily infiltrated with lymphocytes (arrowheads in C), which may play a role in the immune rejection of seminomas and contribute to the favorable prognosis of these neoplasms. (Reprinted with permission from Easr Carolina University, School of Medicine, Department of Pathology slide collection.)

D. Testicular teratocarcinoma (Figure 25-6)

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Figure 25-6. Light micrograph of testicular teratocarcinoma (TC). Teratocarcinoma is another type of germ-cell neoplasm that is composed of a collection of well-differentiated cells or structures from each of the three primary germ layers. (A) Teratocarcinoma is composed of a fibrous stroma with many cyst-like structures (asterisk). In addition, well-differentiated glandular structures resembling colon glandular epithelium (endoderm; box I), cartilage (mesoderm; box 2), and squamous epithelium (ectoderm; box 3). (R) High magnification of glandular structures. (C) High magnification of cartilage. (D) High magnification of squamous epithelium. (Reprinted with permission from East Carolina University, School of Medicine, Department of Pathology slide collection.)

E. Normal prostate gland (Figure 25-7; see V)

Figure 25-7. Light micrograph of normal prostate gland. Tubuloalveolar glands are lined by a simple columnar epithelium surrounded by a connective tissue stroma. Corpus amylacca are observed within the lumen.

E. Normal prostate gland (Figure 25-7; see V)

Figure 25-7. Light micrograph of normal prostate gland. Tubuloalveolar glands are lined by a simple columnar epithelium surrounded by a connective tissue stroma. Corpus amylacca are observed within the lumen.

F. Benign prostatic hyperplasia (Figure 25-8)

F. Benign prostatic hyperplasia (Figure 25-8)

Figure 25-8. Light micrograph of benign prostatic hyperplasia, which is the most common disorder of the prostate gland and generally occurs in elderly men. The mucosal and submucosal glands close to the urethra are characteristically enlarged so that compression of the urethra occurs with resulting difficulty in urination. Dihydrotestosterone is the main mediator of prostate growth. In older men, 17ß-estradiol levels increase and inay sensitize the prostate gland to the effects of dihydrotestosterone. (A) Low magnification shows a proliferation of both glands within a fairly well-defined nodule (dotted lines) and the connective tissue stroma. The epithelium of the glands characteristically forms papillary buds or infoldings (arrows), which arc much more prominent than in the normal prostate. Other glands are cystically dilated (asterisk). (B) High magnification of the boxed area in A shows hyperplastic glands and stroma infiltrated by lymphocytes (dotted area). (C) High-magnification hyperplastic glands lined by a conspicuous epithelium oftall columnar cells that appear multilayered in some locations (arrows). Within the lumen, corpus amylacea and papillary buds or infoldings can be seen. (Reprinted with permission from East Carolina University, School of Medicine, Department of Pathology slide collection.)

Figure 25-8. Light micrograph of benign prostatic hyperplasia, which is the most common disorder of the prostate gland and generally occurs in elderly men. The mucosal and submucosal glands close to the urethra are characteristically enlarged so that compression of the urethra occurs with resulting difficulty in urination. Dihydrotestosterone is the main mediator of prostate growth. In older men, 17ß-estradiol levels increase and inay sensitize the prostate gland to the effects of dihydrotestosterone. (A) Low magnification shows a proliferation of both glands within a fairly well-defined nodule (dotted lines) and the connective tissue stroma. The epithelium of the glands characteristically forms papillary buds or infoldings (arrows), which arc much more prominent than in the normal prostate. Other glands are cystically dilated (asterisk). (B) High magnification of the boxed area in A shows hyperplastic glands and stroma infiltrated by lymphocytes (dotted area). (C) High-magnification hyperplastic glands lined by a conspicuous epithelium oftall columnar cells that appear multilayered in some locations (arrows). Within the lumen, corpus amylacea and papillary buds or infoldings can be seen. (Reprinted with permission from East Carolina University, School of Medicine, Department of Pathology slide collection.)

G. Prostatic carcinoma (Figure 25-9)

Figure 25-9. Light micrograph of prostatic carcinoma (PC). PC is the most common form of cancer in men. PC generally starts in the main glands of the prostate located at the periphery near the capsule. Therefore, by the time blockage of the urethra occurs, PC is already in an advanced state. The most reliable sign of malignancy is the invasion of the capsule that contains lymphatics, blood vessels, and nerves. The finding of osteoblastic metastasis in bone, particularly lumbar vertebral bodies, is diagnostic of PC. (A) Low magnification of PC showing the main glands of the prostate near the capsule. Numerous small malignant acini can be observed lying side-by-side to each other (arrows). (B, C) High magnification of the boxed area in A shows malignant acini lined by cuboidal epithelium (arrows). The acini may be filled with cell nests. In a poorly differentiated PC, acini are not apparent; instead, cords of neoplastic cells invade the stroma. (Reprinted with permission from East Carolina University, School of Medicine, Department of Pathology slide collection.)

Figure 25-9. Light micrograph of prostatic carcinoma (PC). PC is the most common form of cancer in men. PC generally starts in the main glands of the prostate located at the periphery near the capsule. Therefore, by the time blockage of the urethra occurs, PC is already in an advanced state. The most reliable sign of malignancy is the invasion of the capsule that contains lymphatics, blood vessels, and nerves. The finding of osteoblastic metastasis in bone, particularly lumbar vertebral bodies, is diagnostic of PC. (A) Low magnification of PC showing the main glands of the prostate near the capsule. Numerous small malignant acini can be observed lying side-by-side to each other (arrows). (B, C) High magnification of the boxed area in A shows malignant acini lined by cuboidal epithelium (arrows). The acini may be filled with cell nests. In a poorly differentiated PC, acini are not apparent; instead, cords of neoplastic cells invade the stroma. (Reprinted with permission from East Carolina University, School of Medicine, Department of Pathology slide collection.)

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