Morphologic and Molecular Characterization of Adrenals and Adrenal Rest Affected by Congenital Adrenal Hyperplasia.

Introduction: Adrenocortical hyperplasia and adrenal rest tumor (ART) formation are common in congenital adrenal hyperplasia (CAH). Although driven by excessive corticotropin, much is unknown regarding the morphology and transformation of these tissues. Our study objective was to characterize CAH-affected adrenals and ART and compare with control adrenal and gonadal tissues. Patients/Methods: CAH adrenals, ART and control tissues were analyzed by histology, immunohistochemistry, and transcriptome sequencing. We investigated protein expression of the ACTH receptor (MC2R), steroidogenic (CYP11B2, CYP11B1, CYB5A) and immune (CD20, CD3, CD68) biomarkers, and delta-like 1 homolog (DLK1), a membrane bound protein broadly expressed in fetal and many endocrine cells. RNA was isolated and gene expression was analyzed by RNA sequencing (RNA-seq) followed by principle component, and unsupervised clustering analyses. Results: Based on immunohistochemistry, CAH adrenals and ART demonstrated increased zona reticularis (ZR)-like CYB5A expression, compared to CYP11B1, and CYP11B2, markers of zona fasciculata and zona glomerulosa respectively. CYP11B2 was mostly absent in CAH adrenals and absent in ART. DLK1 was present in CAH adrenal, ART, and also control adrenal and testis, but was absent in control ovary. Increased expression of adrenocortical marker MC2R, was observed in CAH adrenals compared to control adrenal. Unlike control tissues, significant nodular lymphocytic infiltration was observed in CAH adrenals and ART, with CD20 (B-cell), CD3 (T-cell) and CD68 (macrophage/monocyte) markers of inflammation. RNA-seq data revealed co-expression of adrenal MC2R, and testis-specific INSL3, HSD17B3 in testicular ART indicating the presence of both gonadal and adrenal features, and high expression of DLK1 in ART, CAH adrenals and control adrenal. Principal component analysis indicated that the ART transcriptome was more similar to CAH adrenals and least similar to control testis tissue. Conclusions: CAH-affected adrenal glands and ART have similar expression profiles and morphology, demonstrating increased CYB5A with ZR characteristics and lymphocytic infiltration, suggesting a common origin that is similarly affected by the abnormal hormonal milieu. Immune system modulators may play a role in tumor formation of CAH.

11C-Metomidate PET/CT Detected Multiple Ectopic Adrenal Rest Tumors in a Woman With Congenital Adrenal Hyperplasia.

CONTEXT: Women with congenital adrenal hyperplasia (CAH) may present with androgen excess that is difficult to control with conventional suppressive doses of glucocorticoids. Clinical management is challenging, and the woman is at great risk of developing steroid-induced complications. PATIENTS AND METHODS: A 32-year-old woman with salt-wasting CAH due to 21-hydroxylase deficiency underwent right-sided adrenalectomy because of a large myelolipoma. Over the years, androgens became increasingly difficult to suppress on prednisolone 5 + 0 + 2.5 mg daily, and at age 39 years the left adrenal with an enlarging myelolipoma was removed. A month later serum testosterone levels had increased from 4.1 preoperatively to 18.3 nmol/L (reference 0.2-1.8 nmol/L), and adrenocorticotropin levels from 32 to 283 pmol/L (reference < 14 pmol/L). No adrenal parenchyma was visualized on computed tomography (CT). In the further search for the source of the markedly elevated testosterone, positron emission tomography (PET) was performed with 2 different tracers, 18fluorodeoxyglucose (18FDG) reflecting glucose metabolism and 11C-metomidate, an inhibitor of 11-ß-hydroxylase targeting adrenocortical tissue. RESULTS: 18FDG-PET/CT with cosyntropin stimulation showed ovarian/paraovarian hypermetabolism, suggestive of adrenal rest tumors. Further characterization with 11C-metomidate PET/CT showed uptakes localized to the ovaries/adnexa, behind the spleen, and between the right crus diaphragmaticus and inferior vena cava. CONCLUSION: Adrenal rest tumors can give rise to high androgen levels in spite of suppressive supraphysiological glucocorticoid doses. This case illustrates, for the first time, the value of 11C-metomidate PET as a sensitive method in documenting adrenal rest tumors, currently considered rare in women with CAH.

11-Oxygenated Androgens Are Biomarkers of Adrenal Volume and Testicular Adrenal Rest Tumors in 21-Hydroxylase Deficiency.

Context: Patients with 21-hydroxylase deficiency (21OHD) have long-term complications, resulting from poor disease control and/or glucocorticoid overtreatment. Lack of optimal biomarkers has made it challenging to tailor therapy and predict long-term outcomes. Objective: To identify biomarkers of disease control and long-term complications in 21OHD. Setting and Participants: Cross-sectional study of 114 patients (70 males), ages 2 to 67 years (median, 15 years), seen in a tertiary referral center. Methods: We correlated a mass-spectrometry panel of 23 steroids, obtained before first morning medication, with bone age advancement (children), adrenal volume (adults), testicular adrenal rest tumors (TART), hirsutism, menstrual disorders, and pituitary hormones. Results: Total adrenal volume correlated positively with 18 steroids, most prominently 21-deoxycortisol and four 11-oxygenated-C19 (11oxC19) steroids: 11ß-hydroxyandrostenedione (11OHA4), 11-ketoandrostenedione (11ketoA4), 11ß-hydroxytestosterone (11OHT), and 11-ketotestosterone (11ketoT) (r ≈ 0.7, P < 0.0001). Nine steroids were significantly higher (P ≤ 0.01) in males with TART compared with those without TART, including 11OHA4 (6.8-fold), 11OHT (4.9-fold), 11ketoT (3.6-fold), 11ketoA4 (3.3-fold), and pregnenolone sulfate (PregS; 4.8-fold). PregS (28.5-fold) and 17-hydroxypregnenolone sulfate (19-fold) levels were higher (P < 0.01) in postpubertal females with menstrual disorders. In males, testosterone levels correlated positively with all 11oxC19 steroids in Tanner stages 1 and 2 (r ≈ 0.7; P < 0.001) but negatively in Tanner stage 5 (r = -0.3 and P < 0.05 for 11ketoA4 and 11ketoT). In females, testosterone level correlated positively with all four 11oxC19 steroids across all Tanner stages (r ≈ 0.8; P < 0.0001). Conclusion: 11oxC19 steroids and PregS might serve as clinically useful biomarkers of disease control and long-term complications in 21OHD.

Abundance of DLK1, differential expression of CYP11B1, CYP21A2 and MC2R, and lack of INSL3 distinguish testicular adrenal rest tumours from Leydig cell tumours.

OBJECTIVE: Testicular adrenal rest tumours (TARTs) are a common finding in patients with congenital adrenal hyperplasia (CAH). These tumours constitute a diagnostic and management conundrum and may lead to infertility. TART cells share many functional and morphological similarities with Leydig cells (LCs), and masses consisting of such cells are occasionally misclassified as malignant testicular tumours, which may lead to erroneous orchiectomy in these patients. DESIGN: In this study, we aimed to investigate the potential of LC developmental markers and adrenal steroidogenic markers in the differential diagnosis of TARTs and malignant LC tumours (LCTs). METHODS: We investigated mRNA and protein expression of testicular steroidogenic enzymes; CYP11A1 and HSD3B1/2, markers of adrenal steroidogenesis; CYP11B1, CYP21A2 and ACTH receptor/melanocortin 2 receptor (MC2R), and markers of LC maturation; and delta-like 1 homolog (DLK1) and insulin-like 3 (INSL3) in testicular biopsies with TART, orchiectomy specimens with LCTs and samples from human fetal adrenals. RESULTS: Expression of testicular steroidogenic enzymes was observed in all specimens. All investigated adrenal steroidogenic markers were expressed in TART, and weak reactions for CYP11B1 and MC2R were observed at the protein level in LTCs. TART and fetal adrenals had identical expression profiles. DLK1 was highly expressed and INSL3 not detectable in TART, whereas INSL3 was highly expressed in LCTs. CONCLUSIONS: The similar expression profiles in TART and fetal adrenals as well as the presence of classical markers of adrenal steroidogenesis lend support to the hypothesis that TART develops from a displaced adrenal cell type. Malignant LCTs seem to have lost DLK1 expression and do not resemble immature LCs. The different expression pattern of DLK1, INSL3 and most adrenocortical markers adds to the elucidation of the histogenesis of testicular interstitial tumours and may facilitate histopathological diagnosis.

Non-functioning adrenocortical carcinoma arising in an adrenal rest: immunohistochemical study of an adult patient.

Adrenal rest is uncommon in adults, and usually represents a small lesion incidentally detected during surgery or autopsy. The adrenal rest can be detected anywhere along the path of embryonic migration of adrenal cortex, including celiac axis, genitals and broad ligament, and may be formed with the separation of cortical fragments by the migration of medullary elements from the sympathochromaffin tissue into the preformed cortical primordium. In addition, even primary adrenocortical carcinoma is a rare tumor with incidence 0.5-2 per million annually; therefore, adrenocortical carcinoma arising in adrenal rests is extremely rare. We encountered a patient with non-functioning ectopic adrenocortical carcinoma in retroperitoneum. A 34-year-old female presented with an incidentally discovered retroperitoneal mass revealed by abdominal ultrasound in her regular health examinations. She did not have any clinical abnormalities and underwent hand-assisted laparoscopic resection of the tumor. A dark-brown tumor, measuring 65 × 56 × 45 mm, was identified in the retroperitoneal space between lower pole of right kidney and inferior vena cava. Histologically, the tumor was predominantly composed of compact eosinophilic cells forming nest-like arrangements and diffusely positive for the steroidogenic factor-1. The tumor met four of the criteria of Weiss used in histological diagnosis of adrenocortical carcinoma (eosinophillic cytoplasm, nuclear atypia, atypical mitosis, and sinusoidal invasion). The tumor cells were immunohistochemically positive for 17α-hydroxylase, dehydroepiandrosterone sulfotransferase and 3ß-hydroxysteroid dehydrogenase, each of which is involved in the synthesis of adrenocortical steroids. Therefore, based on these findings, we diagnosed this tumor as ectopic adrenocortical carcinoma arising in adrenal rest of retroperitoneum.

Malignant adrenal rest tumor of the retroperitoneum producing adrenocortical steroids.

We present a case of a malignant adrenal rest tumor arising from the retroperitoneum with Cushing's syndrome in a 31-year-old female. Her serum cortisol and dehydroepiandrosterone sulfate levels were elevated, while adrenocorticotropic hormone levels were low. Computed tomography scans and magnetic resonance imaging revealed a retroperitoneal tumor with no visible lesions in the adrenal glands and ovaries. From those results and the histopathologic findings following biopsy of an enlarged supraclavicular lymph node, the patient was diagnosed as a malignant adrenal rest tumor of the retroperitoneum. Despite chemotherapy, the patient died of rapid development of multiple metastases. Autopsy revealed a large tumor that extended around the abdominal aorta from the levels of the left kidney to the aortic bifurcation with generalized metastases. Tumor cells were characterized by clear and eosinophilic cytoplasm and atypical nuclei that exhibited frequent and atypical mitoses. Immunohistochemistry regarding steroidogenesis was performed and revealed that the tumor cells were immunopositive for adrenal 4 binding protein/steroidogenic factor-1, cholesterol side-chain cleavage enzyme, 17α-hydroxylase, and 21-hydroxylase. We thus elucidated the adrenocortical steroid production in the tumor cells causing Cushing's syndrome. This case report first demonstrates the steroidogenic capacity in a malignant adrenal rest tumor.

Testicular adrenal rest tumours in boys with congenital adrenal hyperplasia: case report and literature review.

Nodular testicular lesions derived from adrenal tissue (testicular adrenal rest tumours - TART) in boys and men with congenital adrenal hyperplasia (CAH) lead to testicular structure damage, spermatogenesis disorders, and infertility. Hyperplasia of the ectopic adrenal tissue in testes is associated with high levels of the adrenocorticotropic hormone (ACTH) in blood serum. The development of non-invasive methods of diagnostic imaging allows detection of testicular lesions in adolescents and children. The basic method for TART detection is imaging with ultrasonography (USG) being the most widely available method. Since these mild testicular lesions can cause impaired fertility, periodic palpation and testicular ultrasonography should be performed in patients with CAH in order to prevent infertility.

An adrenal rest tumour in the perirenal region in a patient with congenital adrenal hyperplasia due to congenital 3beta-hydroxysteroid dehydrogenase deficiency.

BACKGROUND: In contrast to the high incidence of testicular adrenal rest tumours (TART) in adult male patients with congenital adrenal hyperplasia (CAH), ovarian adrenal rest tumours in female CAH patients are very rare and other locations of adrenal rest tumours have never been reported. Here, we report on an adult patient with CAH due to 3beta-hydroxysteroid dehydrogenase (HSD) deficiency with bilateral TART and additionally a large perirenal adrenal rest tumour. CASE REPORT: The patient was known with CAH due to 3beta-HSD deficiency and treated with hydrocortisone and fludrocortisone since the neonatal period. In puberty, there was lack of compliance with consequently high POMC concentrations. At the age of 16 years, bilateral TART were detected by scrotal ultrasound. Intensifying glucocorticoid medication did not result in decrease in POMC concentrations and shrinkage of size of the tumours. At the age of 23 years, abdominal ultrasound was performed because of abdominal complaints, showing a round inhomogeneous structure with a diameter of 4 cm near the left renal hilus. A computer tomography scan showed a multinodular lesion in the retroperitoneal region beside the left kidney. Histological investigation after removal of the tumour showed sheets of large polygonal cells with abundant eosinophilic cytoplasm, separated by dense fibrous tissue strands. The histological and immunohistochemical profile resulted in a diagnosis of an adrenal rest tumour. CONCLUSION: In adult CAH patients, ectopic adrenal rest tumours can be present outside the testicular region. Further investigations are necessary to determine whether regularly screening for these tumours is useful.

Testicular tumors in patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency show functional features of adrenocortical tissue.

CONTEXT: In male patients with congenital adrenal hyperplasia (CAH), testicular adrenal rest tumors are frequently found that may interfere with gonadal function. OBJECTIVE: Our objective was to determine steroid-producing features of testicular adrenal rest tumors. DESIGN AND SETTING: The study is descriptive and took place at a university medical center. PATIENTS: Eight adult CAH patients with bilateral testicular adrenal rest tumors were treated with testis-sparing surgery. INTERVENTIONS: In all but one patient, spermatic veins were cannulated during surgery and blood samples collected to measure the adrenal-specific steroid 21-deoxycortisol (21DF) and 17-hydroxyprogesterone (17OHP) and androstenedione (A). The same parameters were measured in simultaneously taken peripheral blood. mRNA concentrations of adrenal-specific enzymes CYP11B1 and CYP11B2 and ACTH and angiotensin II (AII) receptors were measured in tumor tissue. MAIN OUTCOME MEASURES: Adrenal-specific steroids/enzymes were assessed. RESULTS: 21DF, 17OHP, and A levels were measurable in all spermatic vein samples. The ratio (mean +/- SD) between spermatic vein and simultaneously taken peripheral blood samples was 37.8 +/- 56.3 (21DF), 132.0 +/- 249 (17OHP), and 57.0 +/- 68.2 (A). CYP11B1, CYP11B2, and ACTH and AII receptor mRNAs were detected in all tumors with a strong correlation between ACTH receptor mRNA in tumors and 21DF (r = 0.85; P = 0.015), 17OHP (r = 1; P = 0.01) and A (r = 0.89; P = 0.007) concentrations in peripheral blood. CONCLUSION: Testicular adrenal rest tumors produce adrenal-specific steroids and express adrenal-specific enzymes and ACTH and AII receptors, confirming the strong resemblance with adrenal tissue. Because AII receptors are present in tumor tissue, it can be hypothesized that AII may be an additional factor responsible for testicular adrenal rest tumor growth.

Bilateral testicular adrenal rests after bilateral adrenalectomies in a cushingoid patient with von Hippel-Lindau disease.

We report a case of bilateral testicular masses in a 25-year-old man with von Hippel-Lindau disease presenting with cushingoid symptoms. His medical history was significant for bilateral adrenalectomies secondary to pheochromocytomas, and he began steroid therapy at that time. After exhaustive endocrinologic, radiographic, and physical examinations, the testicular masses were postulated to be active adrenal rest tissue. Bilateral testicular venous sampling found elevated glucocorticoids that were responsive to dexamethasone suppression, which confirmed the testicular masses as testicular adrenal rests without the need for surgical intervention. Successful conservative management consisted of appropriate steroid manipulation and radiographic evaluation and resulted in the resolution of presenting symptoms, a decrease in size of the bilateral testicular masses, and testicular conservation in this young man.

Adrenal rest tumor of the liver: a case report with immunohistochemical investigation of steroidogenesis.

A case of adrenal rest tumor arising in the liver of a 62-year-old male with chronic hepatitis type C is reported. The tumor was clinically non-functioning and required distinction from hepatocellular carcinoma. The yellowish-brown tumor measured 25 x 18 x 15 mm and was located in the subcapsular portion of the right hepatic lobe. Histologically, the tumor presented features similar to those of the adrenal cortex and was predominantly composed of pale cells. Electron micrograph revealed lipid droplets and mitochondria with tubulo-vesicular cristae, consistent with the characteristics of steroid-producing cells. Immunohistochemically, the tumor expressed the adrenal 4 binding protein and a number of enzymes involved in the synthesis of adrenocortical steroids. At surgery, the right adrenal gland was present independently from the liver. This hepatic tumor was considered to be an adrenal rest tumor with steroidogenic capability.

Proliferation and maturation indices in nephrogenic rests and Wilms tumor; the emergence of heterogeneity from dormant nodular renal blastema.

Independent nephrogenic rests (NRs) accompany many Wilms tumors (WTs), exhibit a range of qualities suggesting dormancy, maturation, regression, and hyperplasia, and may carry the WT-1 mutation. We assessed nucleolar organizer regions, proliferating cell nuclear antigen (PCNA) activity, cytoplasmic filament expression, and nuclear morphology in 79 nephrogenic rests accompanying 20 WTs. We found a direct relationship between the size of a blastematous NR and the AgNOR number per nucleus and a close correlation with PCNA activity. The blastema of most NRs > 1 cm in diameter was indistinguishable from blastema of most WTs. The smallest NR usually had a low number of silver-reactive nucleolar organizing regions (AgNORs), low PCNA activity, and absent cytoplasmic filaments, all characteristics of a nascent dormant state in which both proliferation rate and protein synthetic activity are low. Intermediate filament expression was variable in blastema of larger NRs; cytoplasmic filaments correlated with emergence of epithelial maturation and absence of filaments with accumulation of immature cells; mature epithelial structures in NRs had low AgNOR number and PCNA activity representing a terminal dormant state. The majority of blastemal cells in most WTs and in one-third of large hyperplastic NRs lack cytoplasmic filaments. This, plus the occasional finding in large NRs of features more typical of WTs such as prevalence of apoptosis, patches of frank necrosis, multinodular architecture, and expanses of monomorphic, poorly vascularized blastema with low PCNA activity, suggest that it may be possible to distinguish NRs that are progressing toward WT from those that are merely hyperplastic. This study refines the concepts of dormancy and hyperplasia as expressed in NRs and provides a general framework for probing the relationship of molecular events to progression of a small proportion of NRs to WT. Criteria used herein to define dormancy and hyperplasia may be useful in assessing lesions other than typical WT, such as unusually large or extensive NRs or uncommon differentiated WTs where the potential for aggressive behavior may be lower than in usual WTs.

Adrenocortical carcinoma--diagnostic and therapeutical implications.

OBJECTIVE: To evaluate the results of treatment of a consecutive series of patients with adrenocortical carcinoma who presented during the six year period 1985 to 1991. DESIGN: Open study. SETTING: Departments of Surgery, Pathology, Endocrinology, and Clinical Chemistry, Sahlgren Hospital, Göteborg, Sweden. SUBJECTS: 10 consecutive patients, two with recurrent and eight with primary adrenocortical carcinoma. INTERVENTIONS: All patients were treated surgically. Two required preoperative embolisation of the tumour vessels to facilitate excision of particularly large tumours, and eight were given adjuvant treatment with mitotane (o,p'-DDD). RESULTS: At a median follow up of 1.5 years (range 3 months, to 21 years) 6 patients were alive with no radiological or biochemical signs of disease; 2 were alive, but with signs of recurrence (at 3 months and 6 years, respectively); and two had died of their disease (at 4 and 8 months, respectively). For the past two years all patients have had their urinary steroid profiles monitored by gas chromatography and mass spectrometry to detect recurrence of the tumour at the earliest possible stage. CONCLUSION: Operation is the treatment of choice for patients with adrenocortical carcinoma, particularly stages I-III. The role of mitotane as adjuvant treatment can be evaluated only in multicentre studies.

Lipid cell tumor of the ovary: steroid hormone secretory pattern and localization using 75Se-selenomethylcholesterol.

Ovarian lipid cell tumors are rare and can be difficult to localize by conventional means. We report a postmenopausal patient where rapid progression of symptoms and very high sebum levels suggested the presence of such a tumor which could not be visualized by computed tomography or ultrasound. Localization was accomplished noninvasively using 75Se-selenomethylcholesterol. Peripheral and ovarian vein steroid concentrations suggest that the tumor produced androgens preferentially by way of the delta 4 steroidogenesis pathway.

Adrenal rest tumor of the liver causing Cushing's syndrome: treatment with ketoconazole preceding an apparent surgical cure.

Ketoconazole, an imidazole derivative known to inhibit cytochrome P450-dependent adrenal enzymes was given to a patient with a functioning adrenal rest tumor of the liver in preparation for surgery. The drug was administered in a stepwise manner for 42 days starting with 400 mg and reaching 1 g the last 4 weeks of the trial. Clear clinical improvement was evident early in the trial and was associated with evidence of amelioration of her hypercortisolism and striking changes in serum and urinary levels of steroid hormones and metabolites. Sex steroids in serum and urine fell dramatically from the first day to the end of the trial. Urinary 17-ketosteroid excretion fell from a basal average of 139 mg/24 h to near normal levels within a week of therapy; serum testosterone fell from a basal level of 2.4 to 0.18 ng/ml; serum 17 beta-estradiol fell likewise from 1096 to 150 pg/ml. In contrast, cortisol levels in serum and urine increased in the first 2 weeks of the trial and subsequently fell to values below the basal levels. Similarly, serum 17 alpha-OH-progesterone levels increased 63% above the basal levels by day 6 of the trial and declined afterwards. Nine months after successful tumor resection the patient is apparently cured as judged by steroid hormone levels and physical appearance. We conclude that ketoconazole was effective in blocking tumoral steroidogenesis which resulted in clinical benefit.

Activation of virilizing adrenal rest tissues by excessive ACTH production. An unusual presentation of Nelson's syndrome.

Nelson's syndrome occurs in 10 to 35 percent of patients treated for Cushing's disease by bilateral adrenalectomy and features an ACTH-producing pituitary tumor and hyperpigmentation. Cortisol-producing testicular tumors activated by markedly elevated ACTH levels have been described in male patients with Nelson's syndrome. We now describe a female patient with Nelson's syndrome who presented with virilization. Abdominal exploration revealed adrenal rest tumors in the paraovarian tissues and adrenal beds. Iodocholesterol scanning gave negative results. This case illustrates the need for follow-up study of patients with bilateral adrenalectomy for Cushing's disease and describes some of the unusual features these patients may present.

Ovarian lipoid cell tumor. Steroid hormones and ultrastructure.

A virilizing, ovarian lipoid cell tumor was removed from a 19-year-old woman with amenorrhea. Light- and electron-microscopic studies of tumor morphology were combined with biochemical measurements of testosterone, dihydrotestosterone, estrone, estradiol, and progesterone. Electron microscopy demonstrated cells with the typical ultrastructural features of steroidogenesis. Analysis of extracts from tumor tissue showed high concentrations of progesterone, testosterone, dihydrotestosterone, estrone, and estradiol. These extracts from the ovarian lipoid cell tumor contained the following quantities of steroids: testosterone 450 ng/g tissue; dihydrotestosterone 56 ng/g tissue; estrone 233 pg/g tissue; estradiol 10896 pg/g tissue; and progesterone 512 ng/g tissue. Ovarian vein blood of the ovary with the lipoid cell tumor showed these results: testosterone 3276 ng/dl; dihydrotestosterone 311 ng/dl; estrone 69 pg/ml; estradiol 258 pg/ml; and progesterone 8.1 ng/ml. Because of the ultrastructural and biochemical similarities of this tumor to granulosa lutein cells it is concluded that this ovarian lipoid cell tumor probably originated from ovarian stromal cells.

Endocrine studies in a patient with functioning adrenal rest tumor of the liver.

We report a case of a calcified liver tumor in a 23 year old female patient who presented with virilization and a mild degree of Cushing's syndrome. Androgen levels were elevated; there was loss of cortisol circadian rhythm and marked increase in urinary 17-ketogenic and 17-ketosteroids which failed to suppress with administration of dexamethasone. Venous sampling by inferior vena cava catheterization showed that the highest steroid hormone levels were in blood from the right hepatic vein. After death, in vitro studies revealed that the tumor contained testosterone and cortisol as determined by immunofluorescence techniques. The adrenals and ovaries were atrophic. Results of metyrapone testing indicated dyshormonogenesis. To our knowledge, this is the first case of an adrenal rest tumor of the liver proved to be functionally active.