Tumor-to-Tumor Metastasis of Lung Cancer to Kidney Cancer: A Review of the Literature and Our Experience.

Tumor-to-tumor metastasis (TTM) is a rare phenomenon documented in patients with multiple primary cancers. This condition is defined as a metastasis between two true primary tumors. The most frequently reported recipient tumor is renal cell carcinoma (RCC), and the lung carcinomas are the most common metastatic tumor donors. Therefore, this paper attempts to address the current gap in knowledge about this rare phenomenon. The first part of this review outlines the recently proposed models and mechanisms involved in the TTM process. The second part then summarizes and analyzes previous case reports in the literature. We also present our experience with the case of lung cancer that metastasized into RCC. Given the sporadic incidence of TTM, no specific management guidelines exist. Therefore, considering TTM in patients with multiple primary tumors is important as it could potentially modify the oncological management offered.

Metastasis infiltrating tumor to meningioma: a case report.

BACKGROUND: There have been many reports of tumor-to-tumor metastasis, in which cancer metastasizes directly into meningiomas. However, metastasis infiltrating tumors in which cancer metastasizes around meningiomas are rare. Therefore, we report a case of metastasis originating from lung cancer that infiltrated meningioma. CASE PRESENTATION: A 79-year-old Japanese woman underwent head magnetic resonance imaging for brain metastasis screening before lung cancer surgery. At that time, asymptomatic meningioma of the left frontal region was accidentally found. Magnetic resonance imaging 6 months later revealed a lesion suspected to be a metastatic brain tumor close to the meningioma. Brain tumor resection was performed, and histopathological diagnosis was meningioma and metastatic brain tumor. Metastatic cancer had invaded the meningioma at the boundary between the brain tumor and metastasis. CONCLUSIONS: A sudden change in imaging findings on routine examination of meningiomas in patients with lung carcinoma may indicate a metastatic brain tumor. The form of cancer metastasis to meningioma is not limited to tumor-to-tumor metastasis, but also includes metastasis infiltrating tumors near the meningioma.

Adenocarcinoma of sigmoid colon with metastasis to an ovarian mature teratoma: A case report.

BACKGROUND: Colorectal cancer ranks third in global cancer-related mortality, often due to metastases to liver and lungs. Ovarian metastases are less common, accounting for 3.6% to 7.4% of cases. In contrast, mature ovarian teratomas are frequently benign. Tumor-to-tumor metastasis is a rare phenomenon, with a limited number of documented cases. Three cases of mature ovarian teratomas metastasizing from different cancers have been reported. This report focuses on a case of tumor-to-tumor metastasis from sigmoid colon adenocarcinoma to a mature ovarian teratoma. CASE SUMMARY: A 41-year-old Taiwanese woman with no known systemic diseases presented with lower back pain, which led to imaging revealing malignant lesions in the spine, pelvis, liver, and multiple lung metastases. She was diagnosed with sigmoid colon adenocarcinoma with metastases to the liver, lung, bone, and a left ovarian teratoma. Treatment involved radiotherapy and chemotherapy, resulting in regression of the primary tumor and stable lung and liver lesions. Due to abdominal symptoms, she underwent exploratory surgery, unveiling a mature teratoma in the left ovary with signs of metastatic adenocarcinoma. CONCLUSION: Consider resecting mature ovarian teratomas with concurrent colorectal adenocarcinoma to prevent tumor-to-tumor metastasis.

Glioblastoma with Probable Intratumoral Adenocarcinoma Metastasis: A Rare Report with Review of Literature.

"Tumor-to-tumor metastasis," an uncommon phenomenon, refers to a primary tumor metastasis into another tumor, with the most frequent donor being lung carcinoma and common recipients being renal cell carcinoma and meningioma. Tumor-to-tumor metastasis occurring in gliomas is rare with less than 20 reports described so far, and that into a glioblastoma is even rarer. We report a 54-year man, diagnosed with glioblastoma, IDH-wildtype, with metastasis of an adenocarcinoma into it. On histomorphology, the glial component was composed of astrocytic cells and showed increased mitosis, microvascular proliferation, and focal necrosis. This was intermingled with an adenocarcinomatous tumor with pleomorphic epithelial cells in glands, nests, and sheets. On immunohistochemistry, the adenocarcinomatous areas were positive for AE1/AE3 and TTF1 but negative for glial markers, ruling out adenoid glioblastoma. Further cytogenetic analysis showed EGFR amplification in the glial component but not in the adenocarcinoma component, ruling out glioblastoma with true epithelial metaplasia, and supporting the diagnosis of adenocarcinoma metastasis into glioblastoma. Glioblastomas may be susceptible to intratumoral metastasis due to the proliferating leaky vascular channels, however, the short survival of patients with glioblastoma may be responsible for the rarity of this occurrence. The documentation of these tumors is important as they may be important for clinical diagnosis and further treatment and prognosis.

Tumor-to-tumor spread: a case report and literature review of renal cell carcinoma metastasis into thyroid cancer.

Tumor-to-tumor metastasis is a rare, yet important entity. Patients with a history of renal cell carcinoma (RCC) may have tumor deposits to the thyroid gland preceding or following their initial cancer diagnosis for many years. The diagnosis can be challenging, and clinicians must remain suspicious of a newly found thyroid nodule in a patient with a history of RCC. In this review, we report a case of a patient with RCC who was incidentally found to have a thyroid nodule on surveillance imaging found to be consistent with tumor-to-tumor metastasis from RCC into papillary thyroid carcinoma. It is imperative to consider this diagnosis as the thyroid is the most common site of spread, and treatment with partial or total thyroidectomy has led to improved survival.

A Rare Presentation of Colon Carcinoma Metastasis Within a Meningioma: A Case Report and Literature Review.

Colon carcinoma with brain metastasis is a rare presentation. This presentation is more unusual and unique when the single brain metastatic lesion has two different types of tumors. This rare phenomenon is known as a tumor-to-tumor metastasis. A meningioma usually hosts lung and breast cancers within it. However, colon carcinoma metastasis into meningiomas has rarely been reported. An 86-year-old man presented with neurological symptoms and was found to have a brain mass. The search for primary lesions was negative as the chest, abdomen, and pelvis CT scan was insignificant. When the brain lesion's pathology revealed a composite mass of adenocarcinoma and a meningioma, further investigation with a colonoscopy revealed a colonic mass as the primary metastasis lesion. This unique presentation and pathology emphasize the importance of a comprehensive investigative approach to finding the primary lesions and consideration of such a phenomenon in these lesions.

Case Report: Tumor-to-tumor metastasis with prostate cancer metastatic to lung cancer: the first reported case.

Tumor-to-tumor metastasis (TTM) occurs rarely in tumor progression, but this event has significant clinical implications. Although the impact of TTM on patient prognosis and survival has been increasingly recognized, understanding of TTM biology and treatment is limited. Prostate cancer is among the most common malignancies threatening male health. Prostate cancer can potentially metastasize to primary lung Cancer; however, this is an exceedingly rare event. We here report for the first time a case of TTM from a prostate cancer to a coexisting primary lung cancer.

Tumor-to-Tumor Metastasis of Medullary Thyroid Carcinoma to Paraganglioma in a Multiple Endocrine Neoplasia Type 2B Patient: A Case Report and Literature Review.

Tumor-to-tumor metastasis is a rare phenomenon in which primary tumor cells metastasize to other tumors. Herein, we report an extremely rare case of tumor-to-tumor metastasis of medullary thyroid carcinoma to a paraganglioma in a patient with multiple endocrine neoplasia type 2B. Based on genetic examination, a 36-year-old woman was diagnosed with multiple endocrine neoplasia type 2B when she was 24 years old. She had a history of total thyroidectomy for medullary thyroid carcinoma and bilateral adrenalectomy for pheochromocytomas, which were performed when she was 15 years and 29 years old, respectively. Follow-up computed tomography demonstrated a retroperitoneal tumor of 30 mm in diameter beside the left kidney and a liver tumor of 16 mm in diameter located in segment 6. The retroperitoneal and liver tumors were surgically resected and examined by a pathologist. Histological examination revealed the classic Zellballen pattern in the retroperitoneal tumor, rendering the diagnosis of a paraganglioma recurrence. Inside the tumor, a white nodule positive for carcinoembryonic antigen, weakly positive for calcitonin, and negative for tyrosine hydroxylase, was identified and diagnosed as a metastatic medullary thyroid carcinoma with high malignant potential. The liver lesion was diagnosed as a metastasis of the medullary thyroid carcinoma. This is the first report of tumor-to-tumor metastasis of medullary thyroid carcinoma to paraganglioma in a patient with multiple endocrine neoplasia type 2B twenty years after total thyroidectomy.

Case report: A rare case of tumor-to-tumor metastasis: metastatic lobular breast carcinoma to clear cell renal cell carcinoma.

Tumor-to-tumor metastasis is a rare phenomenon. Although renal cell carcinoma is the most common recipient tumor, metastatic lobular breast carcinoma to clear cell renal cell carcinoma is even rarer, with only one case reported to date. We present a 66-year-old female patient with an invasive lobular carcinoma history who was admitted to the hospital with a right renal mass. The patient received partial nephrectomy. The final established diagnosis is lobular breast carcinoma metastasizing to clear cell renal cell carcinoma (ccRCC). Thus, although rare, the simultaneous or consecutive find of a renal mass in follow-up should be carefully evaluated, especially in high-risk patients, including women with an advanced breast cancer history, as in this scenario.

Clinical, cytological, and pathological characteristics of metastatic renal cell carcinoma to the thyroid: A study of 14 cases at a Japanese single institution.

A preoperative diagnosis of metastatic renal cell carcinoma to the thyroid (MRCCT) is important for determining clinical management but is challenging even in cases with a clinical history of renal cell carcinoma (RCC). This study aimed to elucidate the clinical, cytological, and pathological characteristics of MRCCT. Fourteen MRCCT cases extracted from 18 320 malignant thyroid tumors were included in this study. Twelve MRCCT (85.7%) occurred as solitary lesions and the most frequently suspected lesions on ultrasonography were follicular tumors. On cytology, 46.2% of cases were reported as RCC or suspected RCC; a medical history of RCC and immunocytochemistry were helpful in interpretation. RCC metastasized to a follicular adenoma in 50.0% of the solitary lesions. MRCCTs with a long interval from the initial presentation, solitary lesion, and Ki-67 labeling index <10% showed significantly longer disease-free survival. MRCCT is characterized by a long interval from the initial presentation of RCC, appearance as a solitary nodule, ultrasonographic similarity to follicular tumors, sharing cytological findings with primary thyroid tumors, and high frequency of metastasis within follicular adenoma. A long interval from the initial presentation, occurrence as a solitary lesion, and low Ki-67 labeling index may be favorable prognostic factors.

Metastasis from follicular lymphoma to an ovarian mature teratoma: a case report of tumor-to-tumor metastasis.

BACKGROUND: Tumor-to-tumor metastasis (TTM) is a rare but well-established phenomenon where histologically distinct tumors metastasize within each other. Here we report the first "known" case of follicular lymphoma that metastasized and extended to a mature ovarian teratoma. CASE PRESENTATION: A 59-year-old Japanese postmenopausal woman visited our hospital for a detailed examination of an ovarian tumor. Clinical imaging suggested it to be either teratoma-associated ovarian cancer with multiple lymph node metastases, or tumor-to-tumor metastasis from malignant lymphoma to ovarian teratoma. A bilateral adnexectomy and retroperitoneal lymph node biopsy were performed. Lined with squamous epithelium, the cyst constituted a mature ovarian teratoma, and the solid part showed diffuse proliferation of abnormal lymphoid cells. Immunohistochemically, the abnormal lymphoid cells were negative for CD5, MUM1, and CyclinD1, and positive for CD10, CD20, CD21, BCL2, and BCL6. Genetic analysis using G-banding and fluorescence in situ hybridization identified a translocation of t(14;18) (q32;q21), and we diagnosed tumor-to-tumor metastasis from nodal follicular lymphoma to mature ovarian teratoma. Twelve months after surgery, the patient showed no progression without adjuvant therapy. CONCLUSIONS: The present case suggests that molecular approaches are useful in the diagnosis of TTM in mature ovarian teratomas when morphologic and immunohistochemical findings alone are insufficient for diagnoses.

Small-cell lung cancer metastasis to a meningioma: Case report and review of the literature.

Tumor-to-tumor metastasis is a rare event with meningioma as the recipient tumor accounting for 20% of the reported cases. The most common primary cancers showing this phenomenon are lung and breast cancer. Most lung cancers metastasizing to a meningioma are due to lung adenocarcinoma with the literature containing only 3 prior reports of small-cell lung cancer showing this pattern of spread. Herein, we present the case of a 67-year-old-patient with small-cell lung cancer that developed a metastasis to a meningioma.

Prostate Adenocarcinoma Within a Thymoma: A Rare Case of Tumor-to-Tumor Metastasis.

Tumor-to-tumor metastasis is defined as when metastasis from a primary tumor (donor) grows in a different primary neoplasm (recipient). Due to the structure of the thymus and the low incidence rate, thymic epithelial neoplasm has been rarely described in the literature as a recipient for metastases.In this report,a patient with advanced prostatic cancer and under control after chemo/hormone therapy was directed to our thoracic surgery unit for an anterior mediastinal mass detected during the staging workup for prostate disease. A limited uptake at fluorodeoxyglucose-positron emission tomography (FDG-PET) in the mediastinal lesion, while the surrounding tissue showed diffusely negative hypermetabolism, suggested a second primary thymic epithelial tumor with a possible carcinomatous differentiation. A thymectomy through a median sternotomy was carried out. Histopathological analysis after thymectomy revealed a type A thymoma with multiple elements of prostate adenocarcinoma within it. The foci of prostate adenocarcinoma were co-located in the context of the thymoma, revealing what is defined as a tumor-to-tumor metastasis.To our knowledge, this is the first report describing a thymoma as the recipient of metastases coming from a primary extrathoracic tumor without the involvement of other thoracic organs.

Tumor-to-Tumor Metastases Involving Clear Cell Renal Cell Carcinomas: A Diagnostic Challenge for Pathologists Needing Clinical Correlation.

Tumor-to-tumor metastasis is a rare event which it is specifically up to pathologists to bring to light correctly. The histological identification of such tumor-to-tumor cases is simple when the respective histologies are different but can be problematic if the case includes two carcinomas with similar cytoarchitecture viewed one inside the other under the microscope. We report four cases of this condition in which clear cell renal cell carcinoma is involved, either as a receptor or as a donor, and remark on the difficulties in recognizing some of them. Appropriate clinical-pathological correlation, including a review of the patient's antecedents and radiological exams, would be a great help in routinely identifying tumor-to-tumor metastases.

Breast Cancer to Meningioma: A Rare Case of Tumor-to-Tumor Metastasis.

Tumor-to-tumor metastasis (TTM) is defined as the hematogenous metastasis within a primary host tumor from a donor neoplasm. Since there is insufficient evidence regarding the pathophysiology, clinical course, and management of TTM, there are no precise guidelines for its management. A 73-year-old female patient diagnosed with breast cancer was found to have convexity meningioma. Since the size of tumor and peritumoral brain edema increased during follow-up period, the meningioma was treated with surgical resection. Postoperatively, histopathologic examination confirmed metastasis of invasive ductal carcinoma within a secretory meningioma. The final diagnosis was TTM of breast cancer in meningioma. Here, we report a rare case of intra-meningioma metastasis and a review of literature to provide a better understanding of this rare phenomenon.

Tumor-to-tumor metastasis to Warthin tumor presenting as an initial sign of breast carcinoma: A case report.

Metastases of distant primary tumors on the parotid gland are very rare. Tumor-to-tumor metastasis to salivary gland tumors is extremely rare. A case of a 69-year-old woman with a large left parotid gland mass with no previous salivary gland problems or cancer. Fine-needle aspiration (FNA) showed evidence of a Warthin tumor. A total left parotidectomy was performed. The final pathology report showed a Warthin tumor containing two metastases of adenocarcinoma. The immunohistochemistry of the metastases led to the diagnosis of primary breast cancer. A negative FNA does not rule out the possibility of a malignant parotid tumor or metastasis, and a parotid lump should be presumed to be a secondary tumor until proven otherwise if the patient has a history of any distant primary cancer. Our patient case serves as a reminder that a new distant primary cancer might be the cause of a parotid lump.

Metastatic Disease to a Concurrent Thyroid Neoplasm: A Case Series and Review of the Literature.

BACKGROUND: Metastatic disease to the thyroid gland is uncommon but well-described. Metastatic disease to a concurrent primary thyroid neoplasm is a rare phenomenon. We sought to study patients with metastasis to the thyroid with a focus on the histopathologic and clinical features in tumor-to-tumor metastasis. METHODS: We identified a series of patients with metastatic disease to the thyroid, with or without a concurrent primary neoplasm, through a search of the files of the Department of Pathology. All relevant slides were retrieved and reviewed, including routine HE and immunohistochemical stains. We performed a detailed English language literature search (1962-2022) and review to identify tumor-to-tumor metastasis involving the thyroid. RESULTS: We identified 14 patients with metastasis to the thyroid over a 22-year period. Four patients exhibited papillary thyroid carcinoma, with metastatic spread of a different malignancy seeding into the thyroid cancer. We describe the histopathologic diagnostic process and findings, clinical management, and the clinical course of tumor-to-tumor metastasis in greater detail for these 4 patients. CONCLUSION: Tumor-to-tumor metastasis to the thyroid is a rare event with unique histopathologic features. Our findings suggest that the phenomenon of tumor-to-tumor metastasis serves to highlight broader mechanisms of metastatic disease in general. We provide the largest-to-date and comprehensive review of the literature to identify all previous reported instances of tumor-to-tumor metastasis involving the thyroid.

Collision tumor of meningioma and metastatic renal clear cell carcinoma: a case report.

Distinct tumors in direct contact with one another are known as collision tumors and collision tumors of meningioma and metastatic renal cell carcinoma have not been previously reported. We report a 71-year-old female with a history of renal cell carcinoma who was presented with slow response and gait imbalance for 4 months. Brain MRI showed a mass in the base of right middle cranial fossa. The mass was completely removed. Histopathologic and radiographic findings provided evidence for a collision composed of meningioma and metastatic renal clear cell carcinoma.

Metastatic melanoma involving a genetically confirmed angiofibroma of soft tissue: A previously unreported type of tumor-to-tumor metastasis.

Tumor-to-tumor metastases are an uncommon phenomenon and are very rare in the context of malignant melanoma. This case report describes a 73-year-old male who underwent an excision of a melanoma from his forehead. Six months later, he developed metastatic disease, including metastasis to a genetically confirmed angiofibroma of soft tissue of the abdominal wall. Angiofibroma of soft tissue is a relatively recently described benign fibrovascular soft tissue tumor, and there appear to be no previous reports of it being a recipient tumor for a metastasis. Awareness of the phenomenon of tumor-to-tumor metastasis and of the distinctive morphologic and molecular genetic features of angiofibroma are critical to avoid misdiagnosis of this very rare event as "dedifferentiated" melanoma.

Metastases to Meningiomas: A Comprehensive Literature Review Including Mediating Proteins.

Approximately 5-15% of solid tumors metastasizing to the central nervous system metastasize to the leptomeninges. Less common, is metastasis to leptomeningeal meningiomas. These are primarily carcinomas of the breast and lung. Awareness of this phenomenon is critical to the evaluation of meningiomas, especially since the metastases may be the first indication of an occult tumor elsewhere in the body. Lack of clear demarcation between the metastasis and meningioma parenchyma, as well as histological features similar to the meningioma, may hinder recognition. The mechanisms underlying metastases anchoring and spread along the leptomeninges are not established. However, several cell adhesion molecules are thought to contribute to this phenomenon. E cadherin is a cell adhesion molecule present in meningioma cells. Binding to endothelium by adhesion molecules such as ICAM, B1 integrin, P-selectin, PECAM-1, CXCL12 and SDF-1 have also been proposed as part of the mechanisms underlying breast carcinoma metastases. In addition, the leptomeninges and meningiomas express mesothelin that acts as an anchoring protein coupling with mucin-16. Consequently, metastatic tumor cell mucin and mesothelin may also facilitate the anchoring of metastases to meningiomas.