Splenic-Gonadal Fusion and Adrenal Cortical Rest Associated with Bilateral Cryptorchism

SPLENIC-GONADAL FUSION AND ADRENAL CORTICAL REST ASSOCIATED WITH BILATERAL CRYPTORCHISM

ALEX E. FINKBEINER, M.D. PAUL A. DERIDDER, M.D. SALLY E. RYDEN, M.D.

From the Departments of Urology and Pathology, University of Michigan Medical Center, and Wayne County General Hospital, Ann Arbor, Michigan

ABSTRACT -A patient with bilateral cryptorchisnt had ectopic splenic tissue adherent to his left testicle and an adrenal cortical rest adherent to his right testicle. The embrylogic basis for these disorders is discussed and the literature reviewed.

Either ectopic splenic or adrenal tissue is occa- ally. On the right side the testicle, epididymis, sionally found in the scrotal compartment or and vas deferens appeared normal. A 2 by 2 adherent to the gonadal-mesonephric struc- mm. nodule was noted to be adherent to the tures. Herein we report the first case of both tunica albuginea of the right testicle. This entities occurring in the same patient. nodule was excised and on frozen section was interpreted to be adrenal rest tissue. An or- Case Report chiopexy was then performed on the right side. The left testicle was grossly abnormal in appear- This four-year-old white male presented with ance and consistency, and appeared to be about bilateral cryptorchism. The patient had a past twice the size of the right testicle. The left history of ventricular septal defect with proba- gonad structures were excised. Postoperatively ble spontaneous closure, asthma, and multiple the patient had an uneventful course. episodes of pneumonia. On physical examina- On histologic section, the 2 by 2 mm. nodule tion the testicles were absent from a slightly adherent to the right testicle was composed of hypodeveloped scrotum, and they were not pal- columns of orderly lipid-filled clear cells con- pable in the inguinal canal. Results of renal sistent with adrenal cortex (Fig. 1A). No renal function tests, electrolytes, and urine analysis medullary elements were present. The left were all normal. A buccal smear revealed a male gonadal structures consisted of a l-cm., spheri- pattern, and intravenous pyelography was nor- cal accessory spleen, with a fibrous capsule and mal. An outpatient trial of 16,000 I.U. of human fibrous trabeculae throughout, with well- chorionic gonadotropin did not induce testicular developed red and white pulp and prominent descent. germinal centers (Fig. 1B). On gross inspection Consequently, in August, 1974, surgical ex- this splenic tissue had been thought to be the ploration was performed. Simultaneous bilateral testis. Also present was a very small, immature inguinal exploration revealed both canals to be testis with poorly developed tubules (Fig. 1C). empty except for rudimentary vasa deferentia. The splenic capsule and tunica albuginea were These were followed into the retroperitoneum joined by loose connective tissue. The where testicular tissue was noted to be invagi- epididymis and vas deferens were also small and nated within the posterior peritoneum bilater- immature.

UROLOGY I OCTOBER 1977 / VOLUME X, NUMBER4 337 FIGURE 1. (A) Ectopic adrenal cortical tissue con- sisting of lipid-jilled cells arranged in orderly columns. (B) Accessory spleen attached to left testis has fibrous capsule and prominent germinal center in white pulp. (C) Left testis is infantile with small, poorly developed tubules. (Hematoxylin and eosin stain, original magni$cation X 20.)

Comment trilobed condensation of mesoderm which later fuses into a single mass. The splenic anlage is Splenic-gonadal fusion visible in the five-week embryo as a prolifera- The incidence of accessory spleens varies be- tion of surface peritoneal cells on the left side of tween 11 and 35 per cent.lm3 They are most the dorsal mesogastrium. The cells break free often found in the immediate neighborhood of and invade the underlying mesenchyma where the spleen, but they may also be found in the they differentiate as spleen. Later the splenic upper omentum, gastrocolic ligament, mesoco- anlage comes into close proximity with the left lon, or pancreas. Only rarely are they found in urogenital fold which includes gonadal other intra-abdominal locations or in the mesoderm and mesonephric components. The scrotum.’ Splenic-gonadal fusion is an abnormal gonad begins its descent about the eighth week connection between the spleen and the gonads and moves caudally during the eighth to twelfth or mesonephric structures. Scrotal spleens are week; thus fusion must occur between the fifth generally within the tunica vaginalis and sepa- and eighth week. This path of descent is some- rated from the testicle and epididymis by a dis- times visibly demonstrated by a band of tissue crete capsule. 4 At least 68 cases of splenic- (fibrous or splenic).2p4*5 gonadal fusion have been reported;5 it is about Splenic-gonadal anomalies are divided into ten times more common in males than females.6 two types: continuous - a cord of either splenic Nine cases of incomplete descent of a fused or fibrous tissue extends from the spleen to the splenic-gonadal structure have been reported. left gonadal-mesonephric structures; and discon- Embryologically splenic-gonadal fusion can be tinuous - the ectopic splenic tissue presents as explained as follows: the spleen develops as a a distinct encapsulated mass adjacent to the

338 UROLOGY i OCTOBER 1977 / VOLUME X, NUMBER 4 gonadal-mesonephric structures with no connec- which is a developmental inclusion of the entire tion to the main splenic tissue.5-8 adrenal or a large portion of the adrenal beneath Histologically, ectopic splenic tissue may re- the capsule of the kidney or liver. This usually semble normal spleen, or may show retrogres- consists of cortical tissue and is always bilateral. sive changes of fibrosis, thrombosis, or calcifica- (2) Accessory adrenal whole gland tissue consists tion. The associated testicular tissue may be of whole gland rests (cortex and medulla) which normal or exhibit changes ranging from mild at- may be found in various locations. (3) Accessory rophic changes to absence of sper- adrenal chromaffin tissue which is medullary ec- matogenesis. 1,3,8 topia. (4) Accessory adrenal cortical tissue which Splenic-gonadal fusion always occurs on the appears to be fairly common near the kidney left side4,7 and is often associated with indirect but may be found anywhere in the re- inguinal hernias. 4,7 The relative high incidence troperitoneum or near the genitalia. of associated cryptochism suggests that fusion Embryologically the adrenal gland has a dou- may interfere with normal gonadal descent4,* ble origin: the cortex arises from coelomic Splenic-gonadal fusion has been noted inci- mesodermal epithelium and the medulla from dentally at autopsy,g herniorrhapy,” and when chromaffin ectodermal cells of the neural performing an orchiopexy for cryptorchism.5 groove. The adrenal primordia and primitive Clinically it may present as an asymptomatic or gonads appear in the vicinity of the mesoneph- painful, swollen scrotal or testicular mass at all ros during the fourth week of fetal life. At this ages. 1-4,7-g*11One patient presented with abdom- time the adrenal primordia lie at the base of the inal pain which proved to be secondary to bowel dorsal mesentary, medial to the cephalic pole of obstruction from extrinsic compression of the the mesonephros, and the primitive gonads colon by a continuous splenic band extending form ventral to the mesonephros immediately from the spleen to the inguinal canal.‘O Thus, adjacent to the adrenals. The cluster of cells of splenic-gonadal fusion frequently presents a the adrenal primordium does not become en- diagnostic problem requiring surgical explora- capsulated until the sixth week, at the time of tion. separation of the adrenal gland from the gonad. A review of 37 cases of splenic-gonadal fusion As the gonads descend, adrenal cortical tissue revealed that 8 of these patients had severe ec- which may adhere to the gonad becomes sepa- tromelia (hypoplasia of the extremities), and 4 of rated from the main adrenal body and descends these 8 had micrognathia as well. It is pos- with the gonad. Ectopic adrenal cortical tissue tulated that a single intrauterine event is re- can thus be expected anywhere along the course sponsible for all three of these congenital of the gonadal vessels. l3 anomalies, since the extremity buds and man- Accessory adrenal cortical tissue found along dibular cartilage form during the time corre- the course of wolffian ducts or their adult de- sponding to fusion of the spleen and testi- rivative structures has been described fre- cle 6.83 quently.16 This tissue has been found along the Although this patient had no congenital limb course of the gonadal vessels, within the broad or facial anomalies, he did have a ventricular ligament, connective tissue of the inguinal septal defect demonstrated by cardiac catheteri- canal, spermatic cord, canal of Nuck, uterus, zation. Since the inter-ventricular foramen nor- hernia sacs, and epididymis or tunica albuginea, mally begins to close by the end of the seventh and adherent to the ovary or testes. 13-16 Adrenal week of fetal life, perhaps one embryologic cortical tissue has never been found within tes- event also induced this patient’s gonadal and ticular or ovarian parenchyma. 13-15 Histologi- cardiac anomalies. cally, medullary cells are absent and the tissue consists mostly of zona fasciculata or reticularis Adrenal cortical rests although some rests may contain glomerulosa as Schechter13 states that adrenal cortical rests well. l5 occur in 50 per cent of newborns and usually These cortical rests may have clinical sig- atrophy and disappear within a few years. In nificance if they present as a scrotal mass; aber- loo males less than one year of age adrenal cor- rant nodules may undergo compensatory hyper- tical nodules were found in or near 15 (7.5 per trophy after adrenalectomy; heterotopic cent) of 200 testes examined at necropsy.14 implants may be excised inadvertently resulting Gualtieri and Segal l5 describe four types of in adrenal insufficiency; and aberrant masses aberrant adrenal tissue: (1) Adrenal heterotopia may themselves become neoplastic. l3

339 UROLOGY / OCTOBER 1977 / VOLUME X, NUMBER 4 Department of Urology 7. Mendez R, and Slorrow JW: Ectopic spleen simulating tes- University of Arkansas College of Medicine ticular tumor, J. Ural. 102: 598 (1969). 8. Putschar WGJ, and Manion WC: Splenic-gonadal fusion, Little Rock, Arkansas 72201 Am. J. Pathol. 32: 15 (1956). (DR. FINKBEINER) 9. Keizur LW: Accessory spleen in the scrotum: report of hvo cases, J. Urol. 68: 759 (1952). References 10. Watson RJ: Splenogonadal fusion, Surgery 63: 853 (1968). 11. Bennet-Jones MJ, and St. Hill CA: Accessory spleen in the 1. Lynch JB, and Kareim OA: Aberrant splenic tissue in the scrotum, Br. J. Surg. 40: 259 (1952). scrotum, Br. J. Surg. 49: 546 (1962). 12. Hines JR, and Effum PR: Splenic-gonadal fusion causing 2. Emmett J&f, and Dreyfuss MI: Accessory spleen in the bowel obstruction, Arch. Surg. 83: 887 (1961). scrotum, Ann. Surg. 117: 754 (1943). 13. Schechter DC: Aberrant adrenal tissue, Ann. Surg. 167: 3. Daniel DS: An mnusual case of ectopic splenic tissue re- 421 (1968). sembling a third testicle, ibid. 145: 960 (1957). 14. Dahl EV, and Bahn RC: Aberrant adrenal cortical tissue 4. May JE, and Bourne CW: Ectopic spleen in the scrotum: near the testis in human infants, Am. J. Pathol. 40: 587 (1962). report of 2 cases, J. Ural. 111: 120 (1974). 15. Cualtieri T, and Segal AD: Report of a case of adrenal-type 5. Mizutani S, Kujohara H, and Sonoda T: Splenic-gonadal fw tumor of the spermatic cord: a review of aberrant adrenal tissues, sion in a Japanese boy, ibirl. 112: 528 (1974). J. Ural. 61: 949 (1949). 6. Sommer JR: Continuous splenic-gonadal fusion with ec- 16. Freeman A: Adrenal cortical adenoma of the epididymis, tromelia: teratogenesis, Pediatrics 22: 1183 (1958). Arch. Pathol. 39: 336 (1945).

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