Myxoid neoplasms of the adrenal cortex: a rare histologic variant

Common Diagnostic Challenges and Pitfalls in Genitourinary Organs, With Emphasis on Immunohistochemical and Molecular Updates

CONTEXT.—

Lesions in the genitourinary (GU) organs, both benign and malignant, can demonstrate overlapping morphology, and practicing surgical pathologists should be aware of these potential pitfalls and consider a broad differential diagnosis for each specific type of lesion involving the GU organs. The following summary of the contents presented at the 6th Annual Chinese American Pathologists Association (CAPA) Diagnostic Course (October 10-11, 2020), supplemented with relevant literature review, exemplifies the common diagnostic challenges and pitfalls for mass lesions of the GU system of adults, including adrenal gland, with emphasis on immunohistochemical and molecular updates when relevant.

OBJECTIVE.—

To describe the common mass lesions in the GU system of adults, including adrenal gland, with emphasis on the diagnostic challenges and pitfalls that may arise in the pathologic assessment, and to highlight immunohistochemical workups and emerging molecular findings when relevant.

DATA SOURCES.—

The contents presented at the course and literature search comprise our data sources.

CONCLUSIONS.—

The diagnostic challenges and pitfalls that arise in the pathologic assessment of the mass lesions in the GU system of adults, including adrenal gland, are common. We summarize the contents presented at the course, supplemented with relevant literature review, and hope to provide a diagnostic framework to evaluate these lesions in routine clinical practice.

Fine needle aspiration cytology of a myxoid adrenocortical adenoma. A case report

The myxoid variant of adrenocortical (AC) tumors is characterized by peculiar histologic features that differ from conventional ones. It shows a prominent myxoid stromal component and is composed of small cells with mild atypia arranged in cords, pseudoglandular structures and microcysts. Reflecting the rarity of this variant, very few cytologic descriptions are available. We describe one case in a 41-year-old woman with a previous diagnosis of breast carcinoma and BRCA1 mutation. During follow-up controls, an adrenal tumor was discovered. Fine needle aspiration cytology and Tru-Cut biopsies were performed simultaneously. Smears showed numerous groups of cohesive cells of intermediate to small size. Within the largest groups, aggregates of myxoid metachromatic material were evident. This myxoid material could also be observed as isolated acellular fragments. While the cytoplasm of most tumoral cells was homogenously stained some showed small vacuoles. Histologically, the tumor grew, forming anastomosing cords, separated by myxoid material that determined microcystic spaces. Immunohistochemistry was characteristic of AC myxoid tumor. After surgery, pathologic analysis confirmed this diagnosis. The tumor showed no necrosis or invasion, had a low mitotic index (3/50 high power fields) and Ki-67 proliferative index of 15%. According to the different diagnostic systems the tumor was classified as an adenoma. In conclusion, the myxoid variant of AC tumors shows peculiar cytologic features. If unaware of the existence of this variant, it can easily be misinterpreted as a metastatic tumor.

Adrenocortical Carcinoma: Updates of Clinical and Pathological Features after Renewed World Health Organisation Classification and Pathology Staging

Adrenocortical carcinoma (ACC) is a heterogenous group of diseases with different clinical behaviour between adult and paediatric patients. In addition, three histological variants, oncocytic, myxoid and sarcomatoid are noted on the recent World Health Organisation (WHO) classification of ACC. A review of recent literature showed that the different types of ACC have distinctive demographic data, clinical presentation, pathology, biological behaviour, genomic and patients' prognosis. In addition, recent updates of pathology staging for ACC allow refinement of prognostic grouping for planning treatment of the patients with ACC. These advances in genomic, pathology and staging have driven the development of standardisation of pathology reporting. International standardisation of pathological reporting of adrenocortical carcinoma and adaption to local pathology communities provide universal platforms for clinicians and researchers involved in the management of patients with ACC. To conclude, all these advances in the field of pathology will improve development of management strategies including improvement of clinical care, development of prognostic markers and testing of novel therapeutic approaches for patients with adrenocortical carcinoma.

[Myxoid variant of adrenocortical carcinoma]

We report two cases of patients presenting myxoid variant of adrenocortical carcinoma (ACC). This very rare variant is characterized by a tumoral proliferation organized in trabeculae, cords or even pseudo-glands within an acellular myxoid materiel stained by Alcian Blue and negative for PAS. Tumor cells have a small to medium size and have little atypia. Their immunohistochemical profil (positivity of Synaptophysin, SF1, Melan A, Vimentin and Inhibin, with a weak or negative pancytokeratin expression) eliminate the main differential diagnoses (metastasis of a myxoid adenocarcinoma and soft tissue myxoid tumor). Many scoring systems have been proposed in order to evaluate the risk of malignancy of these lesions: the Weiss score seems less efficient to evaluate malignancy in this variant than the reticulinic algorithm or the Helsinki score. Prognosis of myxoid variant of ACC seems worse than classical ACC.

Challenges in surgical pathology of adrenocortical tumours

Adrenocortical carcinomas are rare tumours that can be diagnostically challenging. Numerous multiparametric scoring systems and diagnostic algorithms have been proposed to differentiate adrenocortical adenoma from adrenocortical carcinoma. Adrenocortical neoplasms must also be differentiated from other primary adrenal tumours, such as phaeochromocytoma and unusual primary adrenal tumours, as well as metastases to the adrenal gland. Myxoid, oncocytic and sarcomatoid variants of adrenocortical tumours must be recognized so that they are not confused with other tumours. The diagnostic criteria for oncocytic adrenocortical carcinoma are different from those for conventional adrenocortical carcinomas. Adrenocortical neoplasms in children are particularly challenging to diagnose, as histological features of malignancy in adrenocortical neoplasms in adults may not be associated with aggressive disease in the tumours of children. Recent histological and immunohistochemical studies and more comprehensive and integrated genomic characterizations continue to advance our understanding of the tumorigenesis of these aggressive neoplasms, and may provide additional diagnostic and prognostic utility and guide the development of therapeutic targets.

Myxoid Adrenocortical Adenoma: A report of two cases and literature review

Myxoid adrenocortical adenomas are uncommon. There were only 61 cases reports documented, and the tumors are tended to be misdiagnosed in virtue of being rare and distinctive histological features. Recently we encountered two myxoid adrenocortical adenoma cases of a 31-year-old Chinese woman and a 45-year-old Chinese man. The patients did not receive further treatment after surgery and were still alive after following up for 20 months. Myxoid adrenocortical adenomas is extremely rare. Recognition of this entity would be beneficial for pathologists to avoid msidiagnosis, and unnecessary treatment.

Myxoid and Sarcomatoid Variants of Adrenocortical Carcinoma: Analysis of Rare Variants in Single Tertiary Care Center

The aim of this study is to describe rare variants of adrenocortical carcinoma (ACC) and to compare the prognosis with that of conventional ACC. We retrospectively reviewed 8 cases of myxoid variant, 1 sarcomatoid variant, and 14 cases of conventional ACC, who underwent surgical resection at the Asan Medical Center between 1996 and 2014. An analysis of the clinicopathological characteristics, including the Weiss score, Ki-67 labeling index, and reticulin framework assessment is presented. The mean age of patients with myxoid/sarcomatoid ACC was 45 years; 4 out of 9 patients were women. Mean primary tumor size was 12.9 cm and the mean weight was 702.4 g. Seven patients presented in an advanced stage (stage III/IV); 8 of these eventually developed distant metastasis. The mean Weiss score was 5.0 points and the Ki-67 labeling index was 15.6%. The extent of myxoid or sarcomatoid change on histological examination ranged from 10% to 75% of the examined tumor areas; reticulin framework alteration was observed in all cases. Four patients showed venous tumor thrombus. Most of the clinicopathological parameters were not significantly different from those of conventional ACC. However, myxoid or sarcomatoid variant (hazard ratios [HR], 3.59; 95% confidence intervals [CI], 1.13-11.38; P = 0.030) and Ki-67 labeling index (HR, 3.97; 95% CI, 1.18-13.41; P = 0.030) were independent predictors of overall survival after adjusting for age and sex. Myxoid or sarcomatoid histological features or an increased Ki-67 labeling index may be associated with poor overall survival in patients with ACC.

Adrenal Tumors in Adults

Although most adrenal tumors are not diagnostic dilemmas, there are cases that are challenging. This may be due to the tissue provided, for example fragmented tissue received in the setting of morcellation, or it may be due to inherently challenging histology, such as in cases with equivocal features of malignancy. Additionally, much has been learned about the molecular alterations of adrenal tumors, especially pheochromocytomas. Many of these alterations represent germline mutations with significant clinical implications for patients and their families. The aim of this review is to provide an overview of the most common adrenal tumors in adults so that pathologists can tackle these interesting tumors.

Adrenal Pathology in the Adult: A Urological Pathologist's Perspective

Adrenal gland diagnostics can pose significant challenges. In most academic and community practice settings, adrenal gland resections are encountered less frequently than other endocrine or genitourinary specimens, leading to less familiarity with evolving classifications and criteria. The unique dichotomy between cortical and medullary lesions reflects the developmental evolution of these functionally independent components. Adrenal cortical lesions at resection include hyperplasia, adenoma, and carcinoma, with some cases straddling the boundary between these distinct clinical classifications. The lack of immunohistochemical or molecular markers to definitively categorize these intermediate lesions enhances the diagnostic challenge. In addition, modified terminology for oncocytic and myxoid cortical lesions has been proposed. Medullary lesions are somewhat easier to categorize; however, the prediction of aggressive behavior in pheochromocytomas remains a challenge due to a lack of reliable prognostic biomarkers. Recent work by the Cancer Genome Atlas Project and other research groups has identified a limited subset of molecular and signaling pathway alterations in these 2 major neoplastic categories. Ongoing research to better define prognostic and predictive biomarkers in cortical and medullary lesions has the potential to enhance both pathologic diagnosis and patient therapy.

Adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is a rare endocrine malignancy, often with an unfavorable prognosis. Here we summarize the knowledge about diagnosis, epidemiology, pathophysiology, and therapy of ACC. Over recent years, multidisciplinary clinics have formed and the first international treatment trials have been conducted. This review focuses on evidence gained from recent basic science and clinical research and provides perspectives from the experience of a large multidisciplinary clinic dedicated to the care of patients with ACC.

Myxoid adrenocortical adenoma: magnetic resonance imaging and pathology correlation

We report a case of a 74-year-old female with myxoid adrenocortical adenoma which showed different magnetic resonance imaging findings compared to those of a typical adrenocortical adenoma. The myxoid change in the adrenocortical adenoma is a rare form of degeneration. It presents a considerable diagnostic challenge to both radiologists and clinicians because it can mimic other adrenal tumor types on imaging. The MRI findings of the presented case included a high signal intensity on T2-weighted images similar to that of fluid and delayed progressive enhancement.

Myxoid adrenocortical carcinoma: a clinicopathologic and immunohistochemical study of 7 cases, including 1 case with lipomatous metaplasia

Adrenocortical carcinomas (ACCs) with myxoid features are rare neoplasms. We identified 7 cases of myxoid ACC and studied the clinicopathologic and immunohistochemical features of these neoplasms. The patients were 5 men and 2 women with a mean age of 45 years. Histologically, the tumors contained alcian blue-positive myxoid areas ranging from 10% to 50% of the tissue examined. One case showed lipomatous metaplasia. Areas of conventional ACC were present in all cases. Immunohistochemically, the tumors were positive for steroid receptor cofactor 1, inhibin, melan A, calretinin, and synaptophysin but negative for high-molecular-weight cytokeratin, CAM5.2, and Pax8. Clinical follow-up information for 4 patients demonstrated that all patients had died of their disease 11 to 69 months after diagnosis. Myxoid ACCs are rare tumors that expand the differential diagnosis of myxoid neoplasms involving the retroperitoneum. Contrary to previous reports proposing that the biologic behavior is similar to conventional ACC, our series seems to indicate that myxoid morphology is associated with more aggressive behavior.

Novel report of an adrenal adenoma in a newborn

An adrenal mass in a newborn usually suggests a diagnosis of neuroblastoma or hemorrhage. A 6-week-old girl was referred for evaluation of a left adrenal mass. The initial findings were most consistent with an adrenal hemorrhage. On surveillance imaging, the lesion was characterized as a complex cystic mass. The patient subsequently developed lesions in the right adrenal gland and liver as well as multiple cutaneous lesions. Although the contralateral adrenal and hepatic lesions resolved spontaneously, the left adrenal and cutaneous lesions persisted. Subsequent imaging revealed that the mural components of the left adrenal mass had increased in size, and at age 13 months, a laparoscopic left adrenalectomy was performed. A benign adrenal adenoma with myxoid changes was reported on surgical pathology. This is the first reported case in a newborn.

Adrenocortical neoplasia: evolving concepts in tumorigenesis with an emphasis on adrenal cortical carcinoma variants

Adrenocortical carcinoma (ACC) is a rare, heterogeneous malignancy with a poor prognosis. According to WHO classification 2004, ACC variants include oncocytic ACCs, myxoid ACCs and ACCs with sarcomatous areas. Herein, we provide a comprehensive review of these rare subtypes of adrenocortical malignancy and emphasize their clinicopathological features with the aim of elucidating aspects of diagnostic categorization, differential diagnostics and biological behavior. The issue of current terminology, applied to biphasic tumors with pleomorphic, sarcomatous or sarcomatoid elements arising in adrenal cortex, is also discussed. We additionally present emerging evidence concerning the adrenal cortical tumorigenesis and the putative adenoma-carcinoma sequence as well.

Myxoid adrenocortical neoplasms: a study of the clinicopathologic features and EGFR gene status of ten Chinese cases

The histopathologic features of 10 myxoid adrenocortical neoplasms were analyzed, and epidermal growth factor receptor (EGFR) expression, EGFR gene copy number, and EGFR gene mutations in the 10 tumors were detected by using immunohistochemical analysis, fluorescence in situ hybridization, and the Scorpion Amplification Refractory Mutation System (DxS, Manchester, England), respectively. Histologically, all 10 tumors varied in their myxoid composition, ranging from 20% to 95%. EGFR protein overexpression was more frequent in myxoid adrenocortical carcinomas (3/4) than in myxoid adrenocortical adenomas (0/6). However, EGFR mutations and EGFR amplification were rare. All patients with adenomas survived for the follow-up period with no recurrence of their tumors or evidence of metastatic disease; 3 patients with carcinoma died of the disease, and 1 is alive with disease. Myxoid changes in adrenocortical neoplasms can be present in adenomas and carcinomas. Detection of EGFR protein expression may be useful in the differential diagnosis between adrenocortical adenomas and adrenocortical carcinomas.

Adrenal cortical tumors, pheochromocytomas and paragangliomas

Distinguishing adrenal cortical adenomas from carcinomas may be a difficult diagnostic problem. The criteria of Weiss are very useful because of their reliance on histologic features. From a practical perspective, the most useful criteria to separate adenomas from carcinomas include tumor size, presence of necrosis and mitotic activity including atypical mitoses. Adrenal cortical neoplasms in pediatric patients are more difficult to diagnose and to separate adenomas from carcinomas. The diagnosis of pediatric adrenal cortical carcinoma requires a higher tumor weight, larger tumor size and more mitoses compared with carcinomas in adults. Pheochromocytomas are chromaffin-derived tumors that develop in the adrenal gland. Paragangliomas are tumors arising from paraganglia that are distributed along the parasympathetic nerves and sympathetic chain. Positive staining for chromogranin and synaptophysin is present in the chief cells, whereas the sustentacular cells are positive for S100 protein. Hereditary conditions associated with pheochromocytomas include multiple endocrine neoplasia 2A and 2B, Von Hippel-Lindau disease and neurofibromatosis I. Hereditary paraganglioma syndromes with mutations of SDHB, SDHC and SDHD are associated with paragangliomas and some pheochromocytomas.

Adrenocortical tumors with myxoid features: a distinct morphologic and phenotypical variant exhibiting malignant behavior

Myxoid changes have been rarely reported both in adrenocortical adenomas and carcinomas. The recent observation by our group of an adrenal myxoid tumor with morphologically borderline features, but aggressive clinical behavior prompted us to review a series of 196 adrenocortical lesions, comprising 122 carcinomas and 74 adenomas, to define the morphologic, phenotypical and clinical characteristics of adrenocortical tumors with myxoid features. Fourteen cases, including 12 carcinomas and 2 borderline tumors, formed the basis of this report, and were characterized by a variably abundant myxoid component (from 5% to 90% of tumor) and 2 distinct cellular growth patterns: the first (10 cases), mostly associated with a predominant myxoid stromal component, was made of small cells with mild atypia arranged in cords and microcysts; the second (4 cases) was characterized by focal myxoid changes in tumors otherwise similar to conventional adrenocortical carcinoma, with large atypical cells having an eosinophilic cytoplasm and a diffuse or nodular architecture. The above mentioned patterns were absent in all adenomas reviewed. A peculiar reactivity to neurofilaments was seen, mostly associated to the presence of predominant rather that focal myxoid stromal changes, and in 40% of conventional adrenocortical carcinomas, thus representing an undescribed potential pitfall in the differential diagnosis of adrenal lesions. Myxoid adrenocortical tumors probably represent a rare but histologically and phenotipically distinct entity and, although rare cases of benign lesions are on record, they seem to be generally associated to morphologic and clinical features of malignancy.

Myxoid adrenal cortical carcinoma presenting as primary hyperaldosteronism: case report and review of the literature

The authors report a case of myxoid adrenal cortical carcinoma (ACC) clinically manifesting as primary hyperaldosteronism. The 82-year-old female patient had a history of hypertension and was sent to the emergency room because of change in consciousness. Ventricular fibrillation occurred, and severe hypokalemia was found. Increased renal loss of potassium, high serum aldosterone level, low renin activity, and a huge tumor in the left suprarenal area were revealed when tests were conducted to determine the cause of her hypokalemia. Left adrenalectomy was performed. The tumor measured 13 cm in diameter and showed a heterogeneous cut surface with gelatinous material. Microscopically, the lesion was composed of polygonal cells with eosinophilic cytoplasm and arranged in arborizing cords in a myxoid background. Capsular and vascular invasion were observed. The tumor stained positive for synaptophysin, melan-A, vimentin, and α-inhibin but negative for cytokeratin. A primary myxoid ACC was diagnosed, which is a rare histological variant. The authors review 13 other reported cases. Most of these were functional tumors causing Cushing syndrome, and only 2 cases presented as primary hyperaldosteronism. All cases had similar microscopic and immunohistochemical features. Distal metastases and local recurrence were not uncommon. Close clinical follow-up is imperative.

Discerning malignancy in resected adrenocotical tumors

BACKGROUND

The number of adrenocortical tumors discovered incidentally has recently increased owing to the advent of imaging techniques. The most important diagnostic point in evaluation of resected specimens of these tumors is to discern malignancy to determine postoperative management of the patients.

OBJECTIVE/METHODS

To determine what the effective methods of discerning malignancy in resected specimens of adrenocortical tumors are at this juncture. To provide relevant and practical information pertinent to those involved in the management of patients with adrenocortical tumors.

CONCLUSION

Careful macroscopic evaluation, including the selection of the specimens submitted and application of the criteria of Weiss for histological diagnosis, is still considered the 'gold standard' for diagnosis of adrenocortical carcinoma. However, it is important to recognize its limitations in the diagnosis of adrenocortical oncocytoma and pediatric adrenocortical tumors. The auxiliary methods that may be of clinical relevance at this juncture include the analysis of the Ki67/MIB-1 labeling index and IGF-II expression in the tumors.

Myxoid adrenal cortical neoplasms

Myxoid adrenal cortical neoplasms are rare, and to our knowledge, only about 23 cases have been reported in the literature, including 13 carcinomas and 10 adenomas. We recently experienced 4 cases of myxoid adrenal cortical neoplasms (3 benign and 1 borderline malignancy) and studied the clinical, histopathological, and immunohistochemical features of these neoplasms. There were 2 male and 2 female patients (age range, 37-61 years, mean, 48 years). All but 1 patient had hormone-related symptoms. The tumors weighed from 24.1 to 94 g (size, 4.1-9.8 cm). They were variably encapsulated with areas of hemorrhage. Histologically, the tumor cells were arranged in delicate arborizing cords or trabecula with myxoid areas varying from 30% to 70%. Three tumors were benign and 1 was of borderline morphology with mitoses of 3/10 high-power fields and mild to moderate nuclear pleomorphism. Two cases contained areas of myelolipomatous component. The tumor cells were positive for vimentin, synaptophysin, and inhibin but negative for cytokeratin. All patients are alive with no recurrence of their tumors or evidence of metastasis (follow-up of 14-20 months). Myxoid changes in adrenal cortical neoplasms are rare but can be seen in both an adenoma and a tumor of uncertain malignant potential. Because of prominent myxoid changes, other myxoid tumors occurring in the retroperitoneum should be excluded. The usual clinical and histological features can be applied to classify the lesions as benign, borderline tumor, or malignant. In our series, there was no case with frank malignant tumor.

Myxoid variant of adrenocortical carcinoma: report of a unique case

Myxoid variant of adrenocortical carcinomas (ACC) are rare, there being only 11 cases in the literature to date. Reported herein are the findings of a case, which in contrast to all previously reported myxoid ACC, was devoid of typical non-myxoid areas. The patient was a 61-year-old man in whom a left adrenal mass was detected during investigation of Cushing's syndrome. The adrenal was replaced by malignant cells and expanses of myxoid material. The cells were positive for melan-A, synaptophysin, vimentin and alpha-inhibin. The ultrastructural features of the cells were typical of adrenal cortical differentiation. The differential diagnosis of myxoid ACC includes extraskeletal myxoid chondrosarcoma, chordoma, myxoid adenocarcinoma, myxoma, lipomatous tumors, nerve sheath tumors, smooth muscle tumors, gastrointestinal stromal tumor and other sarcomas. The presence of myxoid material in a retroperitoneal lesion raises a broad differential diagnosis in which myxoid adrenocortical neoplasms should be included. Clinicoradiological correlation may be helpful, but special stains, immunohistochemistry and ultrastructural examination may be necessary to establish the diagnosis.

Is laparoscopic adrenalectomy feasible for adrenocortical carcinoma or metastasis?

OBJECTIVE

To review our experience with laparoscopic adrenalectomy (LA), to evaluate the effectiveness and safety of this procedure in patients with adrenal malignancy.

PATIENTS AND METHODS

The study included patients who underwent LA from 1995 to 2002, with histologically identified adrenocortical cancer (ACC) or metastasis. Indications for LA were adrenal masses with no radiological evidence of involvement of the surrounding structures, or solitary metastasis with well-controlled primary cancer. The variables evaluated were: size of the lesion, operative duration, estimated blood loss, intraoperative complications, local, port-site and intra-abdominal recurrence, distant metastasis, and survival time.

RESULTS

Fourteen malignant adrenal lesions in 205 LAs (7%) were confirmed with histological diagnoses that showed a primary ACC in six and metastasis in another seven (in one there was bilateral metastasis). The mean (sd) size of the malignant lesions was 5.9 (2.8) cm. The 12 unilateral procedures required a mean operative duration of 164 (47) min; the bilateral procedure lasted 215 min. There was one conversion to open surgery caused by local infiltration, whereas there were no intraoperative complications. The mean follow-up was 30 months, during which three patients died, one from endoperitoneal and trocar port-site seeding.

CONCLUSION

When the malignancy is confined to the adrenal gland, LA seems to be a feasible option if the principles of oncological surgery are respected. Nevertheless, further investigations are required to evaluate the appropriateness of this operation.

Myxoid adrenocortical adenoma with a pseudoglandular pattern

Myxoid changes rarely occur in adrenocortical adenomas and carcinomas. Only eight benign tumours with such features have been described thus far, five of which also had a prominent pseudoglandular component. We report an additional pseudoglandular myxoid adenoma of the adrenal gland detected in a 58-year-old male patient who developed mild hypertension. At surgery, a 4-cm mass was resected and found to contain cords and tubules of polygonal cells in a myxoid background. Limited areas of classical adrenocortical adenoma were detected in less than 20% of the tumour area. Lack of atypias and absence of mucin markers, together with an immunophenotype consistent with adrenal tumours (focal cytokeratin, vimentin, synaptophysin and alpha-inhibin immunoreactivities), led to a diagnosis of primary adrenocortical adenoma with an extensive pseudoglandular myxoid pattern. However, the differential diagnosis from metastatic well-differentiated adenocarcinomas, chordomas and retroperitoneal myxoid mesenchymal tumours (e.g. liposarcoma) may be difficult in the absence of a complete clinical history and a reliable immunoprofile. We strongly recommend staining of any myxoid or glandular tumour of the adrenal gland for alpha-inhibin and synaptophysin (probably the currently best characterised markers of adrenocortical origin) before considering alternative (probably more common) diagnoses of metastatic adenocarcinoma or retroperitoneal tumours localised to the adrenal gland.

Non-functional adrenocortical adenoma with extensive degeneration

We report a case of non-functional adrenocortical adenoma of 5.5 x 5.5 x 3.2 cm in size that had an unusual histopathological appearance in two respects. First, the tumor contained small adipose foci with osteogenesis and was suspected of being a myelolipoma based on its appearance on computerized tomography (CT) and magnetic resonance imaging. However, pathologically, the fat element was seen focally and was not accompanied by hematopoietic cells, and the diagnosis of myelolipoma was abandoned. Second, the tumor was suspected of being an adrenal carcinoma based on its appearance on CT scans and showed extensive degeneration: fibrosis, hemorrhage, loss of parenchyma and moderate atypism of the tumor cells. However, as the architecture of the tumor cells was non-diffuse and there were no necrotic foci or mitoses, and vascular or capsular invasion were not present, the tumor was concluded to be an adrenocortical adenoma rather than a carcinoma. We diagnosed the tumor as a non-functional adrenocortical adenoma with extensive degeneration as the extensive areas of fibrosis were particularly remarkable. Furthermore, the extensive areas of degeneration might have been caused not only by an ischemic effect but also by low hormone levels.

Adrenal cortical carcinomas with myxoid differentiation in the domestic ferret (Mustela putorius furo)

A total of 15 adrenocortical carcinomas with myxoid differentiation from 15 ferrets were evaluated in this retrospective study. Six of these ferrets (40%) either were euthanatized or died due to invasive and/or metastatic disease. The myxoid component was a variable part (between 5% and 95%) of the adrenal cortical neoplasm and consisted of sheets and cords of small, polygonal neoplastic cells that formed lumenlike spaces. Such spaces contained a variable amount of alcian blue (pH 2.5)-positive mucinous product (i.e., acidic mucopolysaccharides). Neoplastic cells were negative for the argentaffin reaction, but immunohistochemically they were strongly positive for vimentin and alpha-inhibin and lightly positive for synaptophysin. Proliferating cell nuclear antigen (PCNA)-labeling indices (LI) of adrenal cortical neoplastic cells within the myxoid component of the neoplasm were significantly elevated (P < 0.05) compared with those of typical neoplastic adrenal cortical cells or the adjacent nonneoplastic zona reticularis. Ultrastructurally, cells in the myxoid component exhibited a typical adrenocortical phenotype characterized by cytoplasmic lipid vacuoles, prominent rough and smooth endoplasmic reticulum, and zonula adherens. This lesion was interpreted as an adrenal cortical carcinoma with myxoid differentiation and appeared to be highly malignant based on PCNA LI, rate of invasion into adjacent tissue, and metastasis (6/15). This report is the first description of this histologic variant in the ferret, which morphologically resembled the rare myxoid variant of adrenocortical carcinoma described in humans.

A case of myxoid adrenocortical carcinoma with extensive lipomatous metaplasia

We report a combination of unusual myxoid change and extensive lipomatous metaplasia of an adrenocortical carcinoma. The patient was a 38-year-old man with hypertension and heart failure. Radiographic examination revealed the presence of a left adrenal tumor, and adrenalectomy was performed. The tumor weighed 380 g and appeared encapsulated. The cut surface was predominantly gelatinous. Histologically, the tumor was composed of atypical round cells with eosinophilic to vacuolated cytoplasm. The tumor was diagnosed as adrenocortical carcinoma. The stroma accumulated copious mucinous material. In addition, individual to nodular mature adipocytes were admixed throughout the tumor. The transition from carcinoma cells to mature adipocytes was recognized. Myxoid change is a very rare phenomenon in adrenocortical carcinoma, and only 10 similar cases have been reported to date. Lipomatous metaplasia is another peculiar feature of adrenocortical lesions that has been reported only in benign conditions. To our knowledge, this is the first reported case of adrenocortical carcinoma with lipomatous metaplasia.

Distinct transcriptional profiles of adrenocortical tumors uncovered by DNA microarray analysis

Comprehensive expression profiling of tumors using DNA microarrays has been used recently for molecular classification and biomarker discovery, as well as a tool to identify and investigate genes involved in tumorigenesis. Application of this approach to a cohort of benign and malignant adrenocortical tissues would be potentially informative in all of these aspects. In this study, we generated transcriptional profiles of 11 adrenocortical carcinomas (ACCs), 4 adrenocortical adenomas (ACAs), 3 normal adrenal cortices (NCs), and 1 macronodular hyperplasia (MNH) using Affymetrix HG_U95Av2 oligonucleotide arrays representing approximately 10,500 unique genes. The expression data set was used for unsupervised hierarchical cluster analysis as well as principal component analysis to visually represent the expression data. An analysis of variance on the three classes (NC, ACA plus MNH, and ACC) revealed 91 genes that displayed at least threefold differential expression between the ACC cohort and both the NC and ACA cohorts at a significance level of P < 0.01. Included in these 91 genes were those known to be up-regulated in adrenocortical tumors, such as insulin-like growth factor (IGF2), as well as novel differentially expressed genes such as osteopontin (SPP) and serine threonine kinase 15 (STK15). Increased expression of IGF2 was identified in 10 of 11 ACCs (90.9%) and was verified by quantitative reverse transcriptase-polymerase chain reaction. Select proliferation-related genes (TOP2A and Ki-67) were validated at the protein level using immunohistochemistry and adrenocortical tissue microarrays. Our results demonstrated significant and consistent gene expression changes in ACCs compared to benign adrenocortical lesions. Moreover, we identified several genes that represent potential diagnostic markers and may play a role in the pathogenesis of ACC.

Pseudoglandular Myxoid Adenoma of the Adrenal Gland

Myxoid tumors of the adrenal cortex are rare. To the best of our knowledge, only 17 cases have been reported to date, including 10 carcinomas and 7 adenomas. The myxoid areas of these tumors are often evident grossly, and their extent is variable. We report on a case of a myxoid adenoma of the right adrenal gland in a 45-year-old male with a prominent pseudoglandular arrangement in more than 90% of the tumor mass, and with a minor component represented by anastomosing cords of tumor cells floating in pools of myxoid material. In addition, after extensive examination, we found foci of typical adrenocortical adenoma. Grossly, the tumor was yellowish without discernable gelatinous changes. Most of the tumor cells had a moderate amount of clear vacuolated cytoplasm and contained numerous oil-red-O-positive lipid droplets. Extracellularly, in the lumens of pseudoglands and on the background, we noticed myxoid material that stained positively with Alcian blue (pH 2.5) and weakly positively with mucicarmine and the PAS method. Immunohistochemical examination showed positivity of the tumor cells for vimentin and cytokeratin CAM5.2. Synaptophysin was weakly positive only focally. Cytokeratin AE1/AE3, EMA, and CEA were negative.

Myxoid adrenal cortical adenoma

Myxoid adrenal cortical adenoma is a rare tumor and, to our knowledge, only 16 cases have been reported. We present the case of a 56-year-old Japanese man who was admitted to hospital because of a right adrenal mass that was discovered during a routine physical examination. The resected mass was well circumscribed and contained canary yellow multinodular regions that were surrounded by a brown gelatinous region. Histologically, the multinodular regions resembled a conventional adrenal cortical adenoma, being composed of solid aggregates of large clear or eosinophilic cells. In the gelatinous region, anastomosing small eosinophilic or vesicular cells were visible within a myxoid stroma that contained large amounts of acidic mucopolysaccharides. Light-microscopic findings were consistent with a diagnosis of adenoma. Immunohistochemical staining revealed that a small number of tumor cells were positive for vimentin, and the MIB-1 labeling index was less than 1%. Flow cytometry demonstrated that cells were diploid. At the ultrastructural level, many fat droplets were found in the large clear cells in the multinodular regions. Small eosinophilic cells in the myxoid region contained many mitochondria but few fat droplets. There were no findings suggestive of malignancy. Although the adrenal cortex might have the potential to produce connective tissue-type mucin as a consequence of its mesodermal origin, the mechanism of production of acidic mucopolysaccharides in a myxoid adrenal cortical tumor remains to be clarified.

Immunoexpression of inhibin alpha-subunit in adrenal neoplasms

Inhibin normally is produced by ovarian granulosa cells and testicular Sertoli cells. Extragonadal inhibin expression also has been detected in the placenta, pituitary gland, and liver. It may be difficult to make a distinction between adrenal cortical tumors, pheochromocytoma, and metastatic carcinomas including renal cell and hepatocellular carcinoma. Immunohistochemical expression of inhibin alpha-subunit was evaluated to determine whether any usefulness of immunostaining could be found for inhibin alpha-subunit in the differential diagnosis of adrenal glandular lesions. The authors performed immunostaining against inhibin alpha-subunit on 5 cases of normal adrenal gland, 1 case of adrenal cortical hyperplasia, 25 cases of adrenal cortical adenoma, 6 cases of adrenal cortical carcinoma, 21 cases of pheochromocytoma, 8 cases of metastatic carcinoma, and 10 cases of primary renal cell carcinoma. Normal adrenal gland showed a strong immunoreactivity against inhibin alpha-subunit, especially in the inner layer of the adrenal cortex, representing the zona reticularis, but adrenal medulla was negative for inhibin alpha-subunit. Adrenal cortical hyperplasia associated with Cushing's syndrome showed a strong, diffuse immunoreactivity for inhibin alpha-subunit. Immunoreactivity against the inhibin alpha-subunit was identified in all cases of adrenal cortical adenoma and carcinoma, especially in the adrenal cortical neoplasm with Cushing's syndrome, which showed a strong reactivity. However, immunoreactivity was absent in two metastatic carcinomas from the liver and colon and most of the pheochromocytomas, except three cases with weak focal positivity for inhibin alpha-subunit. Four cases of metastatic renal cell carcinoma and 10 cases of primary renal cell carcinoma revealed no immunoreactivity. Metastatic adenocarcinoma from the prostate showed a weak immunoreactivity for inhibin alpha-subunit. Metastatic hepatoblastoma was negative against inhibin alpha-subunit with endogenous biotin blocking. Immunoexpression for inhibin alpha-subunit is useful for making distinction between adrenal cortical tumors, pheochromocytoma, and metastatic carcinoma. Inhibin alpha-subunit may be valuable as part of a diagnostic immunohistochemical panel in adrenal glandular lesions.

Pathologic features and expression of insulin-like growth factor-2 in adrenocortical neoplasms

We analyzed a series of adrenocortical neoplasms to compare the clinicopathologic features and the expression of insulin-like growth factor-2 (IGF-2) in adrenocortical adenomas and carcinomas. IGF-2 is a growth factor commonly expressed in many tumors including adrenal cortical and medullary neoplasms. Formalin-fixed paraffin-embedded tissues from 64 adrenocortical adenomas and 67 adrenocortical carcinomas were analyzed. The carcinomas were histologically graded from 1 to 4 based on mitotic activity and necrosis. Tumor weight, size, and follow-up information were obtained by chart review. Expression of IGF-2 was detected by immunohistochemistry with the avidin-biotin-peroxidase complex method and a monoclonal antibody against IGF-2. Adrenocortical carcinomas were larger (mean: 13.1 cm, 787 g) than adenomas (mean: 4.2 cm, 52 g) (p < 0.001). Inpatients with adrenocortical carcinomas, high tumor grade (3 or 4) (p = 0.01) was associated with decreased survival. Expression of IGF-2 was higher in adrenocortical carcinomas than in adenomas (p < 0.001). These results show that tumor size and weight along with expression of IGF-2 protein are useful features to assist in distinguishing between adrenocortical adenomas and carcinomas, and that high tumor grade is a predictor of survival in adrenocortical carcinomas. However, single immunohistochemical markers such as IGF-2 or single histopathologic features cannot by themselves separate adrenocortical adenomas from carcinomas, and a combination of clinical, gross, and microscopic features are needed to establish the diagnosis in difficult cases.