Distinguishing Clear Cell Renal Cell Carcinoma, Retroperitoneal Paraganglioma, and Adrenal Cortical Lesions on Limited Biopsy Material: Utility of Immunohistochemical Markers

Metastatic Adrenocortical Carcinoma to the Skin: A Case Report and Review of This Unusual Neoplasm

ABSTRACT

Adrenocortical carcinoma is a very rare oncologic condition with poor prognosis that usually metastasizes to the lungs, liver, local lymph nodes, and peritoneum at initial presentation. However, skin metastasis is very uncommon and has rarely been reported even in advanced stages of the disease. We present a case of a 41-year-old man with a known history of adrenocortical carcinoma of the right adrenal gland that presented with an arm mass. The histopathologic sections showed a multinodular necrotic malignant neoplasm in dermis and subcutaneous fat composed of atypical epithelioid cells with ample granular cytoplasm and pleomorphic vesicular nuclei with frequent intranuclear inclusions and atypical mitoses. The immunohistochemical stains showed tumor cells that were strongly positive for synaptophysin and inhibin, only focally positive for Melan-A, and negative for AE1/AE3. The histopathologic features and the immunohistochemical profile confirmed the diagnosis of metastatic carcinoma consistent with adrenal cortical origin. The diagnosis can be difficult (especially when no clinical data are provided), and an immunohistochemical battery is often useful in distinguishing this tumor from other tumors with similar cytomorphological features.

Pan-keratin Immunostaining in Human Tumors: A Tissue Microarray Study of 15,940 Tumors

To evaluate the efficiency of pan-keratin immunostaining, tissue microarrays of 13,501 tumor samples from 121 different tumor types and subtypes as well as 608 samples of 76 different normal tissue types were analyzed by immunohistochemistry. In normal tissues, strong pan-keratin immunostaining was seen in epithelial cells. Staining intensity was lower in hepatocytes, islets of Langerhans, and pneumocytes but markedly reduced in the adrenal cortex. Pan-keratin was positive in ≥98% of samples in 62 (83%) of 75 epithelial tumor entities, including almost all adenocarcinomas, squamous cell and urothelial carcinomas. Only 17 of 121 tumor entities (13%) had a pan-keratin positivity rate between 25% and 98%, including tumors with mixed differentiation, endocrine/neuroendocrine tumors, renal cell carcinomas, adrenocortical tumors, and particularly poorly differentiated carcinoma subtypes. The 15 entities with pan-keratin positivity in 0.9%-25% were mostly of mesenchymal origin. Reduced/absent pan-keratin immunostaining was associated with high UICC stage (p = 0.0001), high Thoenes grade (p = 0.0183), high Fuhrman grade (p = 0.0049), advanced tumor stage (p < 0.0001) and lymph node metastasis (p = 0.0114) in clear cell renal cell carcinoma, advanced pT stage (p = 0.0007) in papillary renal cell carcinoma, and with advanced stage (p = 0.0023), high grade (p = 0.0005) as well as loss of ER and PR expression (each p < 0.0001) in invasive breast carcinoma of no special type (NST). In summary, pan-keratin can consistently be detected in the vast majority of epithelial tumors, although pan-keratin can be negative a fraction of renal cell, adrenocortical and neuroendocrine neoplasms. The data also link reduced pan-keratin immunostaining to unfavorable tumor phenotype in in epithelial neoplasms.

Diagnostic and prognostic utility of SF1, IGF2 and p57 immunoexpression in pediatric adrenal cortical tumors

BACKGROUND

Adrenocortical tumors (ACT) are uncommon in the pediatric age group. Using the standard Weiss criteria in pediatric tumors leads to overdiagnosis. This has led to the development of newer systems such as Weineke criteria. Ki67 labeling index aids in differentiating adenomas from carcinomas. We aim to evaluate the diagnostic and prognostic role of Ki67 labeling index, along with immunoexpression of steroidogenic factor-1, insulin like growth factor 2 and p57, in pediatric ACTs diagnosed using Weineke criteria.

METHODS

We have studied 25 cases of pediatric ACTs. Immunohistochemical staining for Ki67, SF-1, IGF2 and p57 was done in all cases and the result was correlated with the morphological diagnosis using the Weineke criteria.

RESULTS

Ki67 labeling index showed complete concordance with the morphological diagnosis. SF-1 and IGF2 showed similar correlation with the diagnosis, with IGF-2 proving to be a more specific marker. Increased Ki67, SF-1 and IGF2 immunostaining also correlated with worse survival. p57 was more specific in determining benign status of a tumor.

CONCLUSION

SF-1 and IGF2 are highly sensitive markers of malignancy in pediatric ACTs and can be used in combination with Ki67 expression for optimal diagnostic and prognostic assessment of pediatric ACTs.

TYPE OF STUDY

Prognosis study.

LEVEL OF EVIDENCE

Level II.

Old, New, and Emerging Immunohistochemical Markers in Pheochromocytoma and Paraganglioma

The evolution of genetic research over the past two decades has greatly improved the understanding of pheochromocytomas and paragangliomas. It is now accepted that more than one third of pheochromocytoma and paragangliomas arise in the context of syndromic disease, usually hereditary. The genetic profile of these tumors also has important prognostic implications which may help guide treatment. Accompanying the changing molecular landscape is the development of new immunohistochemical markers. Initially used in assisting with diagnosis, immunohistochemical markers have now become an important adjunct to screening programs for inherited conditions and subsequently as prognostic markers. The accessibility and efficiency of immunohistochemistry bring pathologists to the forefront in triaging patients based on tumor genotype-phenotype. In this review, we provide an update on the role of immunohistochemistry in the diagnosis of pheochromocytomas and paragangliomas, as an adjunct to assessment for hereditary disease and finally as a potential tool to assist risk stratification.

Immunohistochemical Biomarkers of Adrenal Cortical Neoplasms

Careful morphological evaluation forms the basis of the workup of an adrenal cortical neoplasm. However, the adoption of immunohistochemical biomarkers has added tremendous value to enhance diagnostic accuracy. The authors provide a brief review of immunohistochemical biomarkers that have been used in the confirmation of adrenal cortical origin and in the detection of the source of functional adrenal cortical proliferations, as well as diagnostic, predictive, and prognostic biomarkers of adrenal cortical carcinoma. In addition, a brief section on potential novel theranostic biomarkers in the prediction of treatment response to mitotane and other relevant chemotherapeutic agents is also provided. In the era of precision and personalized medical practice, adoption of combined morphology and immunohistochemistry provides a new approach to the diagnostic workup of adrenal cortical neoplasms, reflecting the evolution of clinical responsibility of pathologists.

Extraneural hemangioblastoma of the kidney: the challenge for clinicopathological diagnosis

Background

Hemangioblastoma is a benign cerebellar tumour which may occur as a sporadic entity or in association with von Hippel-Lindau (VHL) disease in approximately 25% of cases. Renal hemangioblastoma (RH) is an extremely rare and newly recognised tumour. Here, we describe five cases of RH, one discovered by CT in an accident and the other four detected during routine examinations.

Methods

Five cases of renal hemangioblastoma retrieved from the Department of Pathology, Fudan University Shanghai Cancer Center were studied and the literatures were reviewed. Immunohistochemistry was used to differentiate and confirm this tumour.

Results

Pathological examination following tumour resection revealed RH in all cases, the first patient was also diagnosed with renal cell carcinoma (RCC), suggesting the possibility of VHL syndrome, but PCR sequencing analysis of the VHL gene confirmed no mutation in any of the three exons, implying sporadic disease .Histologically, the tumours were circumscribed, composed of sheets of oval or polygonal cells and a prominent vascular network. Tumour cells had pleomorphic nuclei, but mitotic figures were rare. The diagnosis of hemangioblastoma was confirmed by immunohistochemistry.

Conclusions

RH is very rare and is challenging to differentially diagnose. Distinguishing RCC and RH is difficult and each has a different prognosis, so differentiating between them is essential for avoiding over-diagnosis and unnecessary treatment.

Value of calretinin immunostaining in diagnostic pathology: a review and update

Calretinin is a member of the EF-hand family of calcium-binding proteins. Because its expression is highly restricted to mesotheliomas, calretinin is, at present, the most commonly used positive mesothelioma marker that is most often recommended to be included in the various immunohistochemical panels used to assist in the differential diagnosis of these tumors. Calretinin expression has also been reported to be commonly expressed in a wide variety of other neoplasms, including sex cord-stromal tumors, adrenal cortical neoplasms, olfactory neuroblastomas, Schwann cell tumors, cardiac myxomas, and ameloblastomas. This article reviews the information that is currently available on calretinin expression in tumors and on its application as an immunohistochemical marker in diagnostic pathology.

Assessing Biological Aggression in Adrenocortical Neoplasia

Pathologists are highly skilled at the evaluation of adrenal neoplasms. Occasional adrenocortical tumors can be diagnostically challenging and supplementary tools can assist in these cases. Histologic and molecular studies support a model that includes 2 broad classes of adrenocortical carcinoma with distinct somatic genetic alterations and clinical outcomes. Pathologists should endeavor to grade adrenocortical carcinomas to assign each case into one of these 2 classes. Mitotic grading by mitotic counting and Ki-67 immunohistochemistry represent the most practicable and informative methods currently available.

Renal paraganglioma: report of a case managed by robotic assisted laparoscopic partial nephrectomy and review of the literature

We describe the pathological and clinical presentation of a rare case of renal paraganglioma occurring as an incidental left renal mass in a 58-year-old woman. The patient underwent robotic assisted laparoscopic partial nephrectomy, which is the first one in the literature.

Renal tumors: diagnostic and prognostic biomarkers

The International Society of Urological Pathology convened a consensus conference on renal cancer, preceded by an online survey, to address issues relating to the diagnosis and reporting of renal neoplasia. In this report, the role of biomarkers in the diagnosis and assessment of prognosis of renal tumors is addressed. In particular we focused upon the use of immunohistochemical markers and the approach to specific differential diagnostic scenarios. We enquired whether cytogenetic and molecular tools were applied in practice and asked for views on the perceived prognostic role of biomarkers. Both the survey and conference voting results demonstrated a high degree of consensus in participants' responses regarding prognostic/predictive markers and molecular techniques, whereas it was apparent that biomarkers for these purposes remained outside the diagnostic realm pending clinical validation. Although no individual antibody or panel of antibodies reached consensus for classifying renal tumors, or for confirming renal metastatic disease, it was noted from the online survey that 87% of respondents used immunohistochemistry to subtype renal tumors sometimes or occasionally, and a majority (87%) used immunohistochemical markers (Pax 2 or Pax 8, renal cell carcinoma [RCC] marker, panel of pan-CK, CK7, vimentin, and CD10) in confirming the diagnosis of metastatic RCC. There was consensus that immunohistochemistry should be used for histologic subtyping and applied before reaching a diagnosis of unclassified RCC. At the conference, there was consensus that TFE3 and TFEB analysis ought to be requested when RCC was diagnosed in a young patient or when histologic appearances were suggestive of the translocation subtype; whereas Pax 2 and/or Pax 8 were considered to be the most useful markers in the diagnosis of a renal primary.

Value of PAX8, PAX2, napsin A, carbonic anhydrase IX, and claudin-4 immunostaining in distinguishing pleural epithelioid mesothelioma from metastatic renal cell carcinoma

Both mesotheliomas and renal cell carcinomas can present a wide variety of cytomorphologic features and histologic patterns. Because of this, renal cell carcinomas metastatic to the pleura and lung can be confused with mesotheliomas. Recently, a variety of positive carcinoma markers, including kidney-associated markers, have become available. The aim of this study is to investigate the value of some of these markers, specifically PAX8, PAX2, napsin A, carbonic anhydrase IX, and claudin-4, for assisting in distinguishing pleural epithelioid mesotheliomas from metastatic renal cell carcinomas. To do so, a total of 40 pleural epithelioid mesotheliomas and 55 renal cell carcinomas (33 clear cell, 10 papillary, and 12 chromophobe) were investigated. In all, 91% of the renal cell carcinomas expressed claudin-4, 89% PAX8, 60% PAX2, 71% carbonic anhydrase IX, and 29% napsin A. All of the mesotheliomas were positive for carbonic anhydrase IX and were negative for all of the other markers. On the basis of these results, it is concluded that claudin-4 and PAX8 have a higher sensitivity and specificity for assisting in discriminating between pleural epithelioid mesotheliomas and renal cell carcinomas when compared with all of the other positive carcinoma markers that are, at present, recommended to be included in the immunohistochemical panels used in this differential diagnosis. Even though PAX2 and napsin A are highly specific, because of their low sensitivity, they have only a limited value. Carbonic anhydrase IX is not useful.

Sporadic hemangioblastoma of the kidney in a 29-year-old man

Hemangioblastoma of the kidney is a rare, newly recognized tumor with morphological features similar to its cerebellar counterpart. There have been only 4 cases reported in the literature in English, all of them occurring in middle-aged to elderly patients. Here, we report a case of renal hemangioblastoma in a young adult without clinical evidence of von Hippel-Lindau disease. The tumor was composed of polygonal cells with mildly eosinophilic to clear cytoplasm and a rich vascular network. Immunohistochemical staining revealed a typical profile (positivity for α-inhibin, neuron-specific enolase and S100; negative results for epithelial membrane antigen, HMB-45, and Melan-A), which confirmed the diagnosis. Despite the similarity to renal-cell carcinoma in morphology, hemangioblastoma of the kidney is clinically indolent. Correct recognition of this pathological entity is important to avoid overdiagnosis and unnecessary clinical treatment.