Synchronous or metachronous presentation of pancreatic neuroendocrine tumor versus secondary lesion to pancreas in patients affected by renal cell carcinoma. Systematic review

The simultaneous or metachronous occurrence of pancreatic neuroendocrine tumor (panNET) and renal cell carcinoma (RCC) may represent a rare coincidence or a manifestation of von Hippel-Lindau disease (VHL). These two malignancies share both radiological and cytopathological features, making the differential diagnosis very challenging. In this review, we collected all cases of concurrent diagnosis of localized panNET and RCC, with or without VHL, as reported in the literature to date. We aimed to provide an insight into the differential diagnosis between panNET and RCC pancreatic metastasis with a focus on the optimal therapeutic algorithm depending on the diagnosis. We performed literature research in PubMed library databases for articles about coexisting panNET and RCC published from 2001 to 2018. We selected nine articles with a total of 13 patients, including one treated at our institution. Patients' median age was 49 years and eight out of 13 patients were women. VHL was diagnosed in nine cases. Most patients underwent radical nephrectomy for RCC (9/13) and a clear cell renal carcinoma variant was identified in six cases. The diagnosis of panNET was synchronous with RCC detection in nine cases and metachronous in four cases. The diameter of the pancreatic lesion was >2 cm in six cases. In two cases the panNET was misdiagnosed as metastatic RCC by radiological tests. Somatostatin receptor scanning was performed only in our patient (Octreoscan) showing intense uptake in the pancreatic mass. Endoscopic ultrasound fine needle aspiration of the pancreatic lesion was performed in four patients: in two cases the panNET was confused with metastatic RCC by cytological analysis. Most patients underwent pancreatic surgery (10/13) without histological confirmation. Clear cell panNET was recognized in six cases, while mixed neuroendocrine non-neuroendocrine neoplasm was diagnosed in one patient. Immunohistochemistry (IHC) staining showed positivity to typical neuroendocrine markers (chromogranin A and synaptophysin) in all reported tested cases (8/8). Three patients underwent systemic treatment: two patients received sunitinib and one patient interleukin-2 (IL-2). Other neoplasms were observed in seven patients, of whom six were affected by VHL syndrome. When neoplastic lesions are recognized in both the kidney and pancreas, panNET and RCC pancreatic metastasis are often misdiagnosed due to similar radiological and cytopathological features. An accurate differential diagnosis is crucial and IHC plays a central role in distinguishing the two entities. The therapeutic algorithm may change depending on the diagnosis: while pancreatic RCC metastases benefit from resection, in panNETs and VHL the indication for surgery must be carefully evaluated.

Initial panel of immunocytochemical markers for identification of primary carcinoma site for effusions and peritoneal washings from women

INTRODUCTION

In women, most malignant effusions are from breast and ovary primary carcinomas that have metastasized to body cavity fluids (pleural, peritoneal and pericardial). When carcinoma is diagnosed in effusions, it is not possible to identify its site of origin solely by cytology (morphology); therefore, immunocytochemistry is used as a complementary method. There are no immunocytochemical markers with 100% sensitivity and specificity for identifying carcinoma primary site. The markers most used are TTF-1 for the lung, GATA-3 for the breast, and PAX-8 for the ovary. The aim of this study was to evaluate the sensitivity and specificity of a panel including these markers for detecting the primary site of carcinoma in effusions.

METHODS

Samples of pleural, pericardial, and peritoneal effusions and peritoneal washings with carcinoma of known primary site from women (n = 60) and men (n = 18) were prepared by using the cell block method, and immunocytochemistry was performed to evaluate the expression of primary site markers (TTF-1, PAX-8, and GATA-3).

RESULTS

In women, the breast was the most frequent primary site of metastatic carcinoma to both pleural and pericardial cavities, followed by the lung, whereas the ovary was the most frequent primary site of carcinoma within peritoneal effusions and washings, followed by the gastrointestinal tract (stomach or intestine). The expected profiles for carcinomas of the most common primary sites were: breast (GATA-3 (+), PAX-8 (-), TTF-1 (-)), ovary (PAX-8 (+), GATA-3 (-), TTF-1 (-)), lung (TTF-1 (+), PAX-8 (-) GATA-3 (-)) and gastrointestinal tract (PAX-8 (-), GATA-3 (-), TTF-1 (-)). These were observed in 88.23% (45/51) of women's samples with carcinoma from these primary sites. By using TTF-1 as the sole primary site marker, 6.25% of carcinomas of primary site other than the lung would have been misdiagnosed.

CONCLUSION

An initial panel of markers including GATA-3, PAX-8, and TTF-1 allows, with high sensitivity and specificity, the identification or exclusion of frequent primary sites of carcinoma in effusions from women. Our results highlight the importance of using a panel of markers to avoid misidentification of the primary site of tumor.

Monoclonal/polyclonal PAX-8, PTH and GATA3 immunohistochemistry in parathyroid lesions

BACKGROUND

Parathyroid gland (PG) is an endocrine organ which may display different immunohistochemical stainings with chief cells and oxyphilic cells in normal as well as hyperplasic/tumoral lesions.

PURPOSE

In this study, we aimed to identify the demographic properties and diagnostic value of the GATA3 antibody, which is a transcription factor in addition to PTH, and of PAX-8 (monoclonal and polyclonal) antibody.

METHODS

We have analyzed in detail the cellular components and staining intensities of 46 adenomas all of which contained parathyroid rims, 12 hyperplasia and 5 adjacent non-neoplastic thyroidectomy materials (63 patients, 114 tissues).

RESULTS

While no staining was identified in the thyroid tissue, cytoplasmic PTH immunoreactivity was observed in all (100%) normal parathyroid tissues, rim of PGs and hyperplasia, and in 43/46 cases (93.4%) of adenomas. Adenoma and hyperplasia were less stained than normal PG (p < 0.05). We detected GATA3 staining in all cases except for the thyroid (100%). Weak positivity (1+) was most apparent in adenoma cases (p < 0.05). Monoclonal PAX-8 immunoreactivity was not identified in any normal parathyroid tissue and rim of PG but positive immunoreactivity was detected in 83.3% of hyperplasia cases (10/12), 84.8% of adenoma (39/46) and 100% of thyroid tissues (5/5) (p < 0.05). However, polyclonal PAX-8 immunoreactivity was detected in one normal parathyroid tissue (1/5) and seven (7/46) rim of PGs. In cases of hyperplasia and adenoma, positive immunoreactivity was 75% (9/12) and 74% (34/46), respectively.

CONCLUSION

In conclusion, we have observed that PTH and GATA3 constitute a much more reliable and sensitive marker for parathyroid and are stained less in adenomas. While monoclonal PAX-8 (MRQ-50) never stains normal parathyroid and rim of PGs, it may help in the differential diagnosis of proliferated parathyroid lesions as a considerably sensitive and relatively specific marker by staining hyperplasic parathyroid, adenomas and the thyroid.

Brenner tumor associated with rete ovarii: a histologic and immunohistochemical analysis of six cases exploring the relationship between these entities

The association of Brenner tumor (BT) with rete ovarii (RO) has been rarely alluded to in the literature. Both entities have debatable histogenesis. In this study of six cases of BT associated with RO, we describe the morphologic features and performed immunohistochemical staining for markers of Mullerian, Wolffian, mesothelial, and sex cord stromal derivation to explore the relationship between these entities. Histologically, all BTs were benign, microscopic, and incidental. RO was prominent and hyperplastic with gradual or abrupt transition to BT. In addition, focal areas of rete entrapped between BT nests were seen. All BTs were positive for GATA-3 and negative for PAX-8. Conversely, the RO in all cases was negative for GATA-3 and positive for PAX-8. WT-1 was positive in both entities. Sex cord stromal and mesothelial markers (other than WT-1) were negative in BT and RO. Although morphologically, BTs seem to arise from RO in these cases, they have a distinct immunophenotype. It is possible that at least some BTs arise from metaplastic changes in RO epithelium.

Bone metastasis of papillary thyroid carcinoma simulating a pulmonary origin. Unusual immunohistochemistry leading to misdiagnosis

Immunophenotypical features from tumors can be variable and, sometimes, confusing. We herein report a 61 year old woman with two foci of papillary thyroid microcarcinoma who developed a bone lesion four months after total thyroidectomy/central lymphadenectomy (mpT1aN0), with an immunohistochemical pattern suggestive of a pulmonary rather than a thyroid origin (CK7, napsin-A and TTF1 positive; and negative thyroglobulin). Further biomarkers (HBME-1 and PAX8) were performed in order to confirm primary tumor, leading to conclusion of a bone metastasis from thyroid papillary carcinoma. We believe it is always advisable to perform more than one biomarker as part of a panel to get a more reliable diagnosis.

A case report of papillary thyroid carcinoma dedifferentiated to squamous cell carcinoma presenting as a lung metastasis: A potential diagnostic pitfall

Papillary thyroid carcinoma (PTC) tall cell variant (TCV) with squamous dedifferentiation is a rare entity. We present a case of 90-year-old woman who initially had a 2.8 cm conventional PTC in right lobe of thyroid who, couple decades later, had metastatic dedifferentiated PTC to right neck lymph nodes level II and IV with tall cell features; to right level IV and V lymph nodes with tall cell and squamous components, which recently presented exclusively as squamous cell carcinoma (SCC) metastasizing to lung. The squamous component in the lymph node and SCC in the lung were both positive for squamous marker p63 and PTC markers TTF1, PAX-8 and BRAF V600E while negative for thyroglobulin and p16. The papillary component was positive for TTF-1, BRAF V600E and P63 (majority); negative for thyroglobulin and p16. Final diagnoses were rendered based on combination of cytological features and immunohistochemical profiles. This report highlights the utilization of current biomarkers to distinguish between metastatic dedifferentiated PTC with squamous features and primary lung SCC, as well as the importance of recognizing this rare entity.

Isolated Gastric Metastasis of Endometrial Adenocarcinoma: First Case Report and Review of Pertinent Literature

Upper gastrointestinal metastasis of endometrial carcinoma rarely occurs in the absence of locoregional disease and other distant metastases. We describe herein the unique case of an isolated gastric metastasis of a stage I endometrial adenocarcinoma. Because the metastatic tumor was initially misdiagnosed clinically and pathologically as a primary gastric carcinoma, we illustrate the histopathology and review the pertinent literature. A 42-year-old woman with Lynch syndrome underwent treatment of endometrial adenocarcinoma at an outside hospital comprising clinical and radiological staging including a positron emission tomography-computed tomography (PET-CT) scan followed by a total intra-abdominal hysterectomy, bilateral salpingoophorectomy and pelvic and paraaortic lymphadenectomy. The preoperative and pathology findings were consistent with a stage I tumor. Three months postoperatively, a PET-CT scan revealed a new 4.4 cm hypermetabolic lesion in the stomach. A biopsy of the lesion was interpreted pathologically as gastric adenocarcinoma with lymphoid stroma. Upon referral of the patient to our center for management, the biopsy was reviewed in consultation and the pathology materials from the hysterectomy procedure were retrieved for comparison. Based on the morphological and immunohistochemical similarities between the tumors the gastric tumor was diagnosed as metastatic endometrial adenocarcinoma. To our knowledge, this is the first documented case of an isolated gastric metastasis complicating stage I endometrial adenocarcinoma. Awareness of the potential for this occurrence and of the associated diagnostic pitfalls is crucial for accurate diagnosis and therapy.

Expression of renal cell markers and detection of 3p loss links endolymphatic sac tumor to renal cell carcinoma and warrants careful evaluation to avoid diagnostic pitfalls

Endolymphatic sac tumor (ELST) is a rare neoplasm arising in the temporal petrous region thought to originate from endolymphatic sac epithelium. It may arise sporadically or in association with Von-Hippel-Lindau syndrome (VHL). The ELST prevalence in VHL ranges from 3 to 16% and may be the initial presentation of the disease. Onset is usually in the 3rd to 5th decade with hearing loss and an indolent course. ELSTs present as locally destructive lesions with characteristic computed tomography imaging features. Histologically, they show papillary, cystic or glandular architectures. Immunohistochemically, they express keratin, EMA, and variably S100 and GFAP. Currently it is recommended that, given its rarity, ELST needs to be differentiated from other entities with similar morphologic patterns, particularly other VHL-associated neoplasms such as metastatic clear cell renal cell carcinoma (ccRCC). Nineteen ELST cases were studied. Immunohistochemistry (18/19) and single nucleotide polymorphism microarray testing was performed (12/19). Comparison with the immunophenotype and copy number profile in RCC is discussed. Patients presented with characteristic bone destructive lesions in the petrous temporal bones. Pathology of tumors showed characteristic ELST morphology with immunoexpression of CK7, GFAP, S100, PAX-8, PAX-2, CA-9 in the tumor cells. Immunostaines for RCC, CD10, CK20, chromogranin A, synaptophysin, TTF-1, thyroglobulin, and transthyretin were negative in the tumor cells. Molecular testing showed loss of 3p and 9q in 66% (8/12) and 58% (7/12) cases, respectively. Immunoreactivity for renal markers in ELST is an important diagnostic caveat and has not been previously reported. In fact, renal markers are currently recommended in order to rule out metastatic RCC although PAX gene complex and CA-9 have been implicated in the development of the inner ear. Importantly copy number assessment of ELST has not been previously reported. Loss of 3p (including the VHL locus) in ELST suggests similar mechanistic origins as ccRCC.

Unraveling molecular targets of bisphenol A and S in the thyroid gland

Bisphenol A (BPA) is a well-known endocrine disruptor with several effects on reproduction, development, and cancer incidence, and it is highly used in the plastic industry. Bisphenol S (BPS) was proposed as an alternative to BPA since it has a similar structure and can be used to manufacture the same products. Some reports show that BPA interferes with thyroid function, but little is known about the involvement of BPS in thyroid function or how these molecules could possibly modulate at the same time the principal genes involved in thyroid physiology. Thus, the aims of this work were to evaluate in silico the possible interactions of BPA and BPS with the thyroid transcription factors Pax 8 and TTF1 and to study the actions in vivo of these compounds in zebrafish thyroid gene expression. Adult zebrafish treated with BPA or BPS showed that sodium iodide symporter, thyroglobulin, and thyroperoxidase genes were negatively or positively regulated, depending on the dose of the exposure. Human Pax 8 alignment with zebrafish Pax 8 and Rattus norvegicus TTF1 alignment with zebrafish TTF1 displayed highly conserved regions in the DNA binding sites. Molecular docking revealed the in silico interactions between the protein targets Pax 8 and TTF1 with BPA and BPS. Importance of some amino acids residues is highlighted and ratified by literature. There were no differences between the mean energy values for BPA docking in Pax 8 or TTF1. However, BPS energy values were lower in TTF1 docking compared to Pax 8 values. The number of amino acids on the protein interface was important for Pax 8 but not for TTF1. The main BPA interactions with proteins occurred through Van der Waals forces and pi-alkyl and alkyl interactions, while BPS interactions mainly occurred through carbon hydrogen bonds and conventional hydrogen bonds in addition to Van der Waals forces and pi-alkyl interactions. These data point to a possible interaction of BPA and BPS with Pax 8 and TTF1.

A rare case of ectopic papillary thyroid carcinoma transformed into squamous cell carcinoma

A rare case of a metastatic ectopic papillary thyroid carcinoma (PTC) of the lung that transformed into a squamous cell carcinoma (SCC) that resembles pulmonary SCC is reported. A subcutaneous ectopic PTC in the left anterior neck area, together with a normal thyroid gland, were excised. The ectopic PTC showed thyroglobulin, TTF-1 and PAX-8 immunoreactivity and a BRAF V600E mutation. During the post-operative follow-up period, a rapidly growing 2 cm nodular lesion in the lower left lobe of the lung was detected. The lung tumor consisted of solid sheets and nests of squamous cells but without the nuclear features of PTC. Neither papillary nor follicular structures of cancer cells were identified. Carcinoma cells were positive for TTF-1, PAX-8, p40, CK14, and p63, while showing a high Ki-67 labeling index and a BRAF V600E mutation. These results support our interpretation of a PTC that originated from ectopic thyroid tissue in the left anterior neck and that developed a lung metastasis showing squamous cell differentiation.

The utility of using immunohistochemistry in the differentiation of metastatic, cutaneous clear cell renal cell carcinoma and clear cell hidradenoma

BACKGROUND

Clear cell hidradenoma and cutaneous clear cell renal cell carcinoma (CCRCC) overlap morphologically. The distinction may be difficult in a patient with a history of CCRCC, presenting with a cutaneous nodule, potentially leading to an erroneous diagnosis. We investigated the usefulness of napsin A and paired box gene 8 (PAX-8) with previously studied markers epithelial membrane antigen (EMA), carcinoembryonic antigen (CEA), vimentin and cluster of differentiation marker 10 (CD10) in differentiating CCRCC from hidradenoma.

METHODS

We evaluated hidradenomas and cutaneous CCRCCs for immunohistochemical expression of napsin A, PAX-8, EMA, CEA, vimentin and CD10.

RESULTS

PAX-8 was expressed in all CCRCCs (8/8) while negative in hidradenomas. Napsin A was negative in both hidradenomas (0/12) and CCRCCs (0/10). EMA showed membranous reactivity in 11 of 12 hidradenomas and 8 of 10 CCRCCs; and highlighted ductal epithelium in 1 of 12 hidradenomas and cystic areas in 4 of 10 CCRCCs. CD10 showed ductal expression in 3 of 12 hidradenomas and membranous staining in 8 of 9 CCRCCs. CEA highlighted ductal epithelium in 11 of 12 hidradenomas while absent in CCRCCs (0/10). Vimentin highlighted neoplastic cells in 8 of 8 CCRCCs and failed to stain the hidradenomas (0/12).

CONCLUSION

A conservative immunohistochemical panel including PAX-8, vimentin and CEA allow for easy distinction of CCRCC from hidradenoma, whereas napsin A added no additional value.