Male repro - testicular neoplasms

Question 1

in what species are testicular neoplasms common

Answer 1

old dogs

Question 2

types of testicular neoplasms

Answer 2

• interstitial (leydig) cell tumor
• sertoli cell tumor
• seminoma (spermatic germinal epithelium)
• 25% of affected testicles have multiple types of neoplasms

Question 3

interstitial cell tumor/adenoma

Answer 3

• most common testicular tumor of dog and bull
• androgens produced by normal interstitial cells but not usually by tumor cells
• nodular hyperplasia: pre-neoplastic change, small non-encapsulated 1-2mm, progresses to 1-2cm

Question 4

gross features of interstitial cell tumor

Answer 4

• no increase in size of testicle
• well demarcated
• yellow-orange
• larger ones have hemorrhagic necrosis
• often incidental findings

Question 5

microscopic features of interstitial cell tumor

Answer 5

• large round to polygonal eosinophilic cells with abundant cytoplasm containing lipochrome pigment
• non-invasive
• seldom metastasize

Question 6

sertoli cell tumor general info

Answer 6

• less common than other testicular tumors
• rare in species other than dog
• more common in older dogs
• often in cryptorchid testicles
• grow to large size in descended testicle with noticeable enlargement grossly

Question 7

functionality of sertoli cell tumor

Answer 7

• produces estrogen
• feminization of male (attracts other males, reduced libido, derm issues, testicular atrophy, pendulous prepuce, gynecomastia, prostatic hyperplasia, bone marrow suppression)

Question 8

gross features of sertoli cell tumor

Answer 8

• cut surface is white
• firm due to fibrous CT stroma (collagen)
• seldom metastasizes (will go to regional lymph nodes)

Question 9

microscopic features of sertoli cell tumor

Answer 9

• pseudotubular arrangement
• cells in tubules line up in palisades at right angles to basement membrane
• foamy lipid-filled cytoplasm
• abundant intertubular connective stroma

Question 10

seminoma general info

Answer 10

• second most common testicular tumor of dog
• old dogs, esp cryptorchids
• non-functional
• usually benign

Question 11

gross features of seminoma

Answer 11

• starts intratubular, breaks into surrounding stroma
• causes swelling, necrosis, pain
• gray-white on cross section

Question 12

microscopic features of seminoma

Answer 12

• large round-polygonal cells
• large nuclei and nucleoli
• many mitotic figures
• foci of lymphocytes within tumor

Question 13

teratoma

Answer 13

• most common testicular tumor of the horse
• found most often in cryptorchid testis
• usually less than 10cm, can be up to 25cm
• cystic tumors (all 3 germ layers)

Question 14

what are the germ cell tumors of the gonad

Answer 14

• teratoma

- dysgerminoma