Bilateral adrenal cortical rests: An interesting innocuous intruder in the fallopian tubes

INTRODUCTION Ectopic adrenal rests are characterized by aberrant localization of adrenal tissue outside the sites of normal adrenal glands like the genitourinary system and pelvis. The fallopian tube, traditionally recognized for its role in reproductive physiology, has not been conventionally associated with adrenal tissue, presenting an intriguing aspect of endocrine pathology, warranting further exploration to comprehend its clinical significance and underlying embryological mechanisms governing the development of adrenal tissue in the fallopian tube.[1] CASE REPORT A 43-year-old female presented to the Obstetrics and Gynecology outpatient department with a complaint of heavy menstrual bleeding for 3 months. On examination, the abdomen was soft; per vaginum cervical erosion was present, followed by an unremarkable pap smear test report. Past medical records revealed an appendicectomy being performed for acute appendicitis a decade ago. Ultrasound of the abdomen showed a bulky uterus with adenomyosis and multiple intramural fibroids, with normal appearing adnexa. A hysterectomy with bilateral salpingo-oophorectomy was performed, and the specimen was sent for histopathological examination. Gross examination revealed multiple intramural fibroids. The cervix, bilateral ovaries, and tubes appeared unremarkable. Microscopy confirmed multiple fibroids and adenomyosis in the uterus with chronic cervicitis. Tubes showed normal plicae with features of salpingitis isthmica nodosa. Additionally, in the parasalpingeal region of both tubes was a well-demarcated capsulated area [Figure 1a]. The nodule was composed of two intermingled but distinct cell populations. All cells had well-defined borders with small, uniform, and pyknotic nuclei. One population showed cells having clear cytoplasm with microvesicular droplets, the other with eosinophilic granular cytoplasm. No atypia or mitosis was seen [Figure 1b and c]. A review of the tubes grossly showed a small bright yellow area measuring less than 0.3 cm in the walls, and on microscopy, the cells resembled adrenal tissue [Figure 2a and b]. On extensive morphological evaluation, Walthard cell nests, ovarian hilus cells, and luteinized theca cells were ruled out. Xanthomatous lesion was excluded as there was no associated inflammation, and the lesion was not diffused. Immunohistochemical (IHC) evaluation revealed cytoplasmic positivity for MelanA. CK7 being negative ruled out Walthard cell nests) which is a most common finding [Figure 2c and d]. Overall, the results confirmed the diagnosis of adrenocortical rests. A detailed history revealed no functional effects of existing adrenal tissue in the patient.

Ectopic adrenal rests are an exceedingly uncommon occurrence, initially documented by Morgagni in 1740. Few cases of ectopic adrenal rests have been reported in young males, primarily in pelvic regions, including testes.[1] In females, such instances are exceptionally rare, with only a handful of cases documented particularly in the fallopian tube[1-5] [Table 1]. Other reported ectopic sites encompass kidney, liver, pancreas, colon, celiac plexus, and ovary.[1] Ordinarily, the adrenal gland has a cortex and medulla. The former develops from the mesoderm of urogenital ridge, while the latter originates from ectodermal neural chromaffin cells. Clumps of cells within the urogenital ridge called the adrenal–gonadal primordium express transcription factor steroidogenic factor-1, which helps in the development of the adrenal gland.[6] Ectopic adrenal remnants typically lack the medulla and are non-functional. They are discovered incidentally during microscopic examination and are usually overlooked grossly. However, close observation may reveal small bright yellow nodules ranging from 1 to 5mm on the tubal wall, as in our case.[7] Microscopically, the adrenal gland exhibits three zones: zona glomerulosa beneath the capsule as a trabecular zone, zona fasciculata with lipid-containing vacuolated cytoplasm, and zona reticularis consisting of lipid-free cells with granular cytoplasm. Ectopic adrenal tissue may show a combination of any of these zones. In our case, morphology was consistent with zona fasciculata and reticularis.[8] Adrenal rests can be functional or non-functional. They are usually clinically silent, as in our case, and become functional when there is ACTH stimulation in conditions like Cushing’s syndrome and Congenital Adrenal Hyperplasia. Clinical implications of functional adrenal rest include reproductive outcomes, subfertility, psychosexual disturbances, and secondary polycystic ovarian syndrome (PCOS).[9,10] Identification of ectopic adrenal rests in the fallopian tube introduces a beguiling dimension to endocrinology and reproductive medicine. Morphological differential diagnoses include metastatic renal cell carcinoma, Sertoli–Leydig cell tumor, Walthard cell nests, histiocyte collections, paraganglioma, ovarian hilus cells, and xanthomatous lesions, most of which can be ruled out with close morphological observation. However, ectopic adrenal rest in this unexpected location underscores the importance of employing IHC markers for accurate identification and characterization for a conclusive diagnosis. Salient IHC markers, which help in differentiating adrenal rest from other diagnoses, are described in Table 2.[1,9] Understanding the developmental origins of these aberrant tissue deposits involves considerations of embryonic migration patterns, cellular differentiation, and the potential influence of genetic factors. Further research in this area is paramount to unravel the full extent of clinical implications, refine diagnostic approaches, and enhance our understanding of the intricate interplay between adrenal tissue and the female reproductive system in atypical anatomical locations.

This case highlights ectopic adrenal rests as an entity that is challenging to visualize macroscopically. It also reiterates the need for detailed observation of specimens by pathologists during grossing to forestall overlooking potentially intriguing entities, as very little attention is paid to the fallopian tube during routine grossing. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Adrenal; ectopic; fallopian tube; Melan A