Tumor-to-tumor metastasis: report of 2 cases of metastatic carcinoma to angiomyolipoma of the kidney

Tumor-to-tumor metastasis is a rare phenomenon. Renal cell carcinoma is the most common recipient of tumor-to-tumor metastasis in malignant tumors. However, renal angiomyolipoma has not been reported to be a recipient. Here we report 2 cases of tumor-to-tumor metastasis to renal angiomyolipoma. In one case, the donor tumor originated from neuroendocrine carcinoma of the pancreas, and in the other case the donor tumor was from adenocarcinoma of the lung. The donor tumors showed morphologic features that did not easily fit into renal angiomyolipoma, and they also demonstrated patterns of immunoreactivity consistent with the primary tumors rather than with renal angiomyolipoma. To our knowledge, these are the first reported cases of tumor-to-tumor metastasis to renal angiomyolipoma. An awareness of this phenomenon is important to avoid an incorrect diagnosis when encountering unusual morphologic features in renal angiomyolipoma.     

Napsin A Expression in Subtypes of Thyroid Tumors: Comparison with Lung Adenocarcinomas

Napsin A is widely used in the diagnosis of lung adenocarcinoma and has also been reported to be positive in cases of thyroid carcinomas. We investigated napsin A levels through immunohistochemistry on whole sections of 210 primary thyroid tumors of various subtypes and another 41 metastatic thyroid carcinomas, and compared these with 125 primary and 25 metastatic lung adenocarcinomas. The results showed that napsin A was expressed in 23.8% thyroid tumors and 30.3% papillary thyroid carcinomas. Most cases showed a focal and weak to moderate expression. In comparison, 80.8% primary lung adenocarcinomas expressed napsin A, with mostly diffused and strong expression. For metastatic carcinomas of thyroid and lung origin, napsin A was detected in 39.0% of thyroid carcinomas in contrast to 88.0% in cases of lung adenocarcinomas. Comparisons of additional markers, TTF-1, CK7, thyroglobulin, and Pax-8 in metastatic carcinomas showed the overlapping expression of immunomarkers of TTF-1 and CK7. Thyroglobulin and Pax-8 were useful for distinguishing between metastatic carcinomas; however, Pax-8 may be a superior marker due to its higher sensitivity. The clinicopathological analysis of papillary thyroid carcinomas showed that the expression of napsin A was positively correlated with lymph node metastasis (p = 0.030). Here, we focused on the expression of napsin A in thyroid tumors and compared it with that in lung adenocarcinomas. The expression of napsin A is common in thyroid tumors and the combined expression of napsin A and TTF-1 in a metastatic thyroid carcinoma is a cause for concern due to chances of misdiagnosis as lung adenocarcinoma.

     

A panel of four immunohistochemical markers (CK7, CK20, TTF-1, and p63) allows accurate diagnosis of primary and metastatic lung carcinoma on biopsy specimens

Accurate classification of lung cancer, as well as the differentiation between primary and metastatic carcinoma to the lung, mostly performed on biopsy or fine needle aspiration specimens, is critical for decisions on therapy and for determining prognosis. The limited amount of biopsy material available for morphological assessment has stimulated attempts to improve diagnostic accuracy through the use of immunohistochemistry (IHC), but an optimal IHC diagnostic algorithm has not been firmly established. We evaluated, on a retrospective series of biopsy specimens, the performance of a four-antibody IHC panel for accurate subclassification of non-small cell lung carcinoma (NSCLC) and for identification of metastatic carcinoma. Tumor morphology was assessed and IHC for CK7, CK20, TTF-1, and p63 was performed according to a two-step algorithm. Matched resection specimens served as gold standard and were compared with the corresponding biopsy. Of 443 biopsy specimens studied, 325 were diagnosed as primary carcinoma of the lung, 198 (44.7 %) as adenocarcinoma, 9 (2 %) as possibly adenosquamous carcinoma, 127 (28.7 %) as squamous cell carcinoma, and 40 (9 %) as NSCLC not further classifiable. Ten cases (2.3 %) were classified as adenocarcinoma of unknown origin and 58 (13 %) as metastasis. Importantly, of the primary lung adenocarcinomas, 35 (17.7 %) had been considered on clinical grounds as a metastasis from a previously diagnosed primary tumor. Of the 55 cases submitted to surgical resection in 47 (85.5 %) the biopsy diagnosis was confirmed, revealing substantial agreement (κ value?=?0.757). Our two-step approach allows for accurate subclassification of NSCLC and also to distinguish between primary lung adenocarcinoma and metastasis, notably of colorectal adenocarcinoma, with crucial implications for appropriate patient management.     

Tumor-to-tumor Metastases to Follicular Variant of Papillary Thyroid Carcinoma: Histologic, Immunohistochemical, and Molecular Studies of Two Unusual Cases

Tumor-to-tumor metastasis in thyroid neoplasms is exceedingly uncommon. Two unusual cases of breast carcinoma and renal cell carcinoma metastatic to follicular variant papillary carcinoma are reported. On histologic sections, the donor tumor cells infiltrated the substance of the recipient tumor and the angiolymphatic channels, but the bulk of metastatic tumor was confined within the thyroid carcinoma. Immunohistochemical stains as well as molecular studies confirmed the origin of both donor tumors, as well as the diagnosis of follicular variant of papillary carcinoma in the recipient tumors. Distinguishing between two such tumor populations may be difficult when the donor tumor cells morphologically resemble primary neoplasms of the recipient organ. A history of previous malignancy and ancillary studies can be helpful in making this distinction and rendering the correct diagnosis. A brief review of literature and discussion of tumor-to-tumor metastasis in thyroid neoplasms is also presented.     

Tumor-to-tumor metastasis: case report of a pulmonary adenocarcinoma metastatic to a clear cell renal cell carcinoma

Tumor-to-tumor metastasis is a very rare event. The recipient tumor may be benign or malignant. Renal cell carcinoma is the most common tumor recipient of metastasis while lung carcinoma is the most common donor tumor. We report a 57-year-old Caucasian male who presented with chest pain. On PET CT Scan, he was also found to have a large renal mass for which he underwent left nephrectomy. On histology of the renal mass, the tumor was a conventional renal cell carcinoma with areas of metastatic non-small cell lung carcinoma. The two components had a distinctive morphology which was confirmed on subsequent immunohistochemistry. The physiopathological mechanisms making clear cell renal cell carcinoma an avid recipient of a metastatic carcinoma have been speculated upon, but are still unknown.     

Cytokeratin 7 and cytokeratin 20 expression in epithelial neoplasms: a survey of 435 cases.

Cytokeratin 7 (CK 7) and cytokeratin 20 (CK 20) are low molecular weight cytokeratins. Their anatomic distribution is generally restricted to epithelia and their neoplasms. We surveyed 435 epithelial neoplasms from various organ systems by immunohistochemistry using CK 7 and CK 20 monoclonal antibodies. Expression of CK 7 was seen in the majority of cases of carcinoma, with the exception of those carcinomas arising from the colon, prostate, kidney, and thymus; carcinoid tumors of the lung and gastrointestinal tract origin; and Merkel cell tumor of the skin. The majority of cases of squamous cell carcinoma of various origins were negative for CK 7, except cervical squamous cell carcinoma, in which 87% of cases were positive. Approximately two thirds of cases of malignant mesothelioma were CK 7-positive. CK 20 positivity was seen in virtually all cases of colorectal carcinomas and Merkel cell tumors. CK 20-positive staining was also observed in cases of pancreatic carcinomas (62%), gastric carcinoma (50%), cholangiocarcinomas (43%), and transitional cell carcinomas (29%). The expression of CK 20 was virtually absent in carcinomas from other organ systems and in malignant mesothelioma. CK 7- and CK 20-negative epithelial neoplasms included adrenal cortical carcinoma, germ cell tumor, prostate carcinoma, renal cell carcinoma, and hepatocellular carcinoma.     

Napsin A (TA02) is a useful alternative to thyroid transcription factor-1 (TTF-1) for the identification of pulmonary adenocarcinoma cells in pleural effusions

The purpose of this study was to test napsin A as a diagnostic marker of metastatic lung adenocarcinoma in pleural effusions, and to compare its performance with TTF-1. Napsin A and TTF-1 reactivities were determined immunohistochemically on formalin-fixed paraffin embedded cell blocks from 50 pleural effusion (5 mesotheliomas, 10 mesothelial proliferations, 12 pulmonary, and 23 nonpulmonary metastases). The results were evaluated separately, and correlated to the final diagnoses. Concordant results were obtained in 48/50 cases. TTF-1 and Napsin A were positive in 8/12 and 10/12 pulmonary adenocarcinomas, respectively. Both markers were negative in 42 cases, including two lung carcinomas. Napsin reactivity was found in more than 75% of the tumor cells in 9/10 positive cases, whereas TTF-1 reactivity was seen in more than 75% of the tumor cells in 2/8 positive cases only (P < 0.05). This makes napsin A an alternative to TTF-1 in cytological diagnosis of effusions in which tumor cells may be scanty.     

Napsin A and WT 1 are useful immunohistochemical markers for differentiating clear cell carcinoma ovary from high‐grade serous carcinoma

Clear cell carcinoma (CCC) of the ovary is an uncommon, but an aggressive epithelial ovarian cancer (EOC), which has overlapping histopathologic features with other ovarian tumours. Lately, Napsin A has been identified as its useful diagnostic immunohistochemical (IHC) marker. Fifty‐eight prospectively diagnosed ovarian CCCs, 53 high‐grade serous carcinomas (HGSCs), 16 endometrioid adenocarcinomas (EMACs), six mixed carcinomas, containing components of CCC and EMAC, seven metastatic mucinous adenocarcinomas and six ovarian yolk sac tumours (YSTs) were tested for Napsin A immunostaining. Fifty ovarian CCCs, 50 HGSCs, seven ovarian EMACs and five mixed carcinomas were tested for WT1 immunostaining. Napsin A was positively expressed in all 58 (100%) CCCs; was focally positive in 1 of 6 YSTs; in 1/16 EMACs and in six cases of mixed carcinomas, while it was negative in all 53 HGSCs and in seven metastatic mucinous adenocarcinomas. Other IHC markers expressed in cases of CCC ovary were CK7 (31/31) (100%), WT1 (0/50), p53 (20/26, ‘wild type’), ER (4/31, focal) (12.9%), PAX8 (14/14) (100%), glypican‐3 (4/10, focal) (44.4%), p16INK4 (5/5, focal) and CK20 (0/5). Various IHC markers expressed in HGSCs were WT1 (48/50) (96%), p53 (31/31, mostly ‘mutation type’), CK7 (9/9) (100%) ER (13/16, variable) (81.2%) and PAX8 (14/14) (100%). IHC markers expressed in EMACs were ER (15/16) (93.7%), CK7 (2/2) (100%) and WT1 (0/7). IHC markers expressed in mixed carcinomas were CK7 (2/2) (100%), WT1 (0/2), focal Napsin A (6/6) and focal ER (5/6). The sensitivity and specificity of Napsin A for the diagnosis of CCC ovary was 100% and 90.9%, respectively. The sensitivity and specificity of WT1 for diagnosis of HGSC ovary was found to be 96% and 100%, respectively. Napsin A and WT1 are highly sensitive and specific IHC markers for diagnosing ovarian CCCs and HGSCs, respectively, and in differentiating these tumours from their mimics. Napsin A is useful in identification of component of CCC in certain EMACs.