Corticomedullary mixed tumour resembling a small adrenal gland-involvement of cancer stem cells: case report

Mixed Corticomedullary Tumor of the Adrenal Gland: A Case Report and Literature Review

Adrenal mixed corticomedullary tumors (MCMTs) are composed of an admixture of cortical and medullary cells. Owing to the presence of two distinct components of different embryonic lineage, these tumors are extremely rare. Less than 30 tumors of this type have been reported to date. MCMTs have varied presentation including hypertension, Cushing syndrome or even as adrenal incidentalomas. Also noted is a slightly higher female preponderance. We report a case of a 26-year-old female who was evaluated for uncontrolled hypertension. A renal ultrasound followed by MRI abdomen revealed a 9.3 × 8.1 × 7.0 cm partially cystic, partially solid enhancing mass in the region of/replacing the left adrenal gland. Hormonal work-up was significant for elevated catecholamines concerning pheochromocytoma. She underwent laparoscopic left adrenalectomy, with adequate pre-operative adrenergic blockade. Histology and immunochemical testing were consistent with a mixed corticomedullary tumor. She was monitored annually for recurrence of the tumor. We also performed a comprehensive review of literature of the cases published so far to the best of our knowledge.

Current Understanding of "Mixed Corticomedullary Adrenal Tumor" and an Insight into Genomic Profiling

BACKGROUND

Malignant mixed corticomedullary adrenal tumors (MCMTs) are extremely rare, with limited cases reported in the literature. The pathophysiology of malignant MCMTs is not well understood; the most prevailing theories are that it is a composite tumor of embryologically derived mesodermal (adrenal cortex) and neural crest (medulla) origin, perpetuating as two distinct cell lines forming a singular mass. Clinical features and laboratory diagnosis are associated with hypersecretions of the adrenal cortex and medulla. Surgical resection is curative in an isolated tumor. We reviewed and compared cases in the literature highlighting the pathogenesis and genetics of benign and malignant MCMT.

METHODS

Comprehensive literature analysis was conducted on PubMed and all the cases of mixed corticomedullary adrenal tumor published in English were included.

RESULTS

Most patients were female (73.1%) with a median age of 49 in women and 50 in men. Surgery was performed in all patients, and in four patients with malignant disease, chemotherapy was used as well. Clinically, most patients presented with hypertension (69%) followed by Cushing syndrome (42%) and diabetes (19%). Tumors often produced cortisol (74%), catecholamines (50%), and adrenocorticotrophic hormone (ACTH) (38%), with lower incidence of aldosterone- (7%) or dopamine (4%)-producing tumors. Immunohistochemical staining of 96% of cases showed Chromogranin-A (73%) and Synaptophysin (62%), followed by Inhibin-α (50%), Melan-A (31%), and S-100 (23%). Of the reported four cases with malignant disease, three showed a Ki-67 index of 40-50% with one showing less than 5%.

CONCLUSION

Mixed corticomedullary adrenal tumors rarely present as a malignant disease requiring chemotherapy. Most MCMTs confer a good prognosis and respond well to surgical resection, though their pathogenesis is largely up to speculation because of limited data. Current theories regarding MCMT pathogenesis should be investigated further with genetic testing. Future research on MCMT may provide ways to guide physician diagnosis and subsequent treatment for refractory cases.

Mixed corticomedullary tumor of the adrenal gland

Mixed corticomedullary tumor (MCMT) of the adrenal gland is an extremely rare tumor characterized by an admixture of steroidogenic cells and chromaffin cells in a single tumor mass simultaneously producing adrenocortical hormones and catecholamines; it is associated with ectopic adrenocorticotropic hormone (ACTH) in some cases. We reviewed and summarized clinicopathological data of 28 MCMTs, including four metastatic tumors in 26 previous reports. These reports included 21 females and 7 males, and the average tumor sizes were 4.8 ± 2.5 cm and 12.6 ± 6.4 cm in the non-metastatic and metastatic groups, respectively (P<0.001). The clinical manifestations and laboratory data were as follows: Cushing or subclinical Cushing syndrome, 58% (14/24); hypertension, 71% (17/24); elevated adrenocortical hormones, 75% (18/24); elevated catecholamines, 75% (18/24); and ectopic ACTH, 71% (10/14). All four patients with metastatic MCMTs had poor prognoses and elevated adrenocortical hormone levels; however, only two patients had elevated catecholamine levels. Immunohistochemistry was essential for the pathologic diagnosis of MCMTs. In this study, using an improved technique, we detected ectopic ACTH-producing cells in the same paraffin-embedded sections reported to be negative in our previous reports. As MCMT is composed of cells with embryologically different origins, its pathogenesis has been explained by various hypotheses. We compared MCMT to the adrenal gland of birds and the early stage of human fetuses, in which nests of chromaffin cells and steroidogenic cells admix without the formation of cortex and medulla. MCMT is characterized by the immaturity of organogenesis and might be classified as an adrenal embryonal tumor.

Mixed Corticomedullary Tumor Accompanied by Unilateral Aldosterone-Producing Adrenocortical Micronodules: a Case Report

Mixed corticomedullary tumors (MCMTs) are rare and comprise medullary and cortical cells in a single adrenal tumor. The mechanisms underlying their development have not been fully elucidated. Here, we report a case of MCMT in a 42-year-old woman. Based on the preoperative clinical findings, the patient was diagnosed as having a pheochromocytoma with subclinical Cushing syndrome. Postoperative pathological diagnosis revealed that the tumor demonstrated morphologically distinct medullary and cortical components, which produced catecholamines and cortisol, respectively. Hybrid tumor cells producing both catecholamines and cortisol were not detected. Adrenocorticotropin (ACTH)-positive tumor cells were identified to be present in the pheochromocytoma. This ectopic production of ACTH can contribute to an autonomous cortisol production in a paracrine manner. In addition, micronodules producing aldosterone were detected in the adrenal tissue adjacent to the tumor. The simultaneous development of these 2 lesions may not be correlated with each other; however, this case confirms the importance of a detailed histopathological examination of the adrenal lesions harboring complicated hormonal abnormalities by providing pivotal and indispensable information on their pathogenesis and the possible interaction of the hormones produced in the adrenal gland.

Adrenal Corticomedullary Mixed Tumor Associated With the FGFR4-G388R Variant

Adrenal corticomedullary mixed tumors (CMMTs) are extremely rare; with only 20 cases being reported to date, the pathogenesis has remained elusive. A 31-year-old woman developed gestational hypertension with psychiatric disturbances persistent to postpartum and was diagnosed with pheochromocytoma, for which adrenalectomy was performed. Histological findings showed mixed adrenocortical adenoma and pheochromocytoma. Double immunostaining of inhibin and INSM1 (insulinoma-associated protein 1) showed that the 2 tumor components had distinct functional properties. Exome analysis of peripheral leukocytes and tumor (singular, as anatomically it is only 1 mass) revealed a homozygous germline FGFR4-G388R variant. As a readout of the variant, serine phosphorylation of signal transducer and activator of transcription 3 (STAT3) was detected only in the nucleus of adrenocortical adenoma component but not in the pheochromocytoma component. No tyrosine phosphorylation of STAT3 was detected. We report a case of CMMT with the germline FGFR4-G388R variant. Although additional studies are required, our immunohistochemical analysis suggests that the variant may play a role in the development of the adrenocortical component within the pheochromocytoma, leading to CMMT.

From ACTH-Dependent to ACTH-Independent Cushing's Syndrome from a Malignant Mixed Corticomedullary Adrenal Tumor: Potential Role of Embryonic Stem Cells

Objective

To report the immunohistochemical and molecular evaluation of a patient with ectopic ACTH syndrome (EAS) from a MCAT which has single cells with features of both 96 medullary and cortical differentiation. Case Description and Methods. A 16-year-old woman presented with severe EAS and a large right MCAT composed of ACTH-secreting cells resembling pheochromocytoma and another lineage similar to adrenal carcinoma. Immunohistochemistry (IHC) showed positivity for medullary (ACTH, chromogranin A, synaptophysin, and PS-100) and epithelial components (inhibin, melan-A, and calretinin). Embryonic stem cell markers were evaluated using RT/PCR and immunofluorescence. After initial surgery, the tumor recurred shifting to rapidly progressive ACTH-independent liver metastasis.

Results

Histopathology and IHC revealed two distinct and intermingled cellular patterns, while some cells immunostained for both medullary and cortical markers. Demonstration of all stem cell biomarkers by RT/PCR and immunofluorescence was predominantly localized to the nucleus, whereas SOX2 immunoreactivity was evident in the cytoplasm as well.

Conclusion

The expression of cancer stem cell biomarkers points towards the involvement of primitive embryonic cells as the origin of this neoplasm and maybe to the clinically aggressive and biochemically changing behavior.