A Comparative Report on Intracranial Tumor-to-Tumor Metastasis and Collision Tumors

A rare case of tumor-to-tumor metastasis of esophageal adenocarcinoma into meningioma

Tumor-to-tumor metastasis is a known but rare occurrence and is characterized as 2 distinct tumor types in same anatomic location. We present a rare case of intracranial tumor-to-tumor metastasis of esophageal adenocarcinoma into meningioma. Our case emphasizes the rare occurrence of intracranial tumor-to-tumor metastasis and importance of histology and immunohistochemical analysis in distinguishing between metastasis and meningioma, especially when faced with ambiguous demarcation. Awareness of this occurrence is crucial, given that metastases might be the initial indication of an underlying tumor and it can impact the clinical management decisions.

A Cerebellar Tumor-to-Tumor Metastasis in a Patient With Von Hippel-Lindau Disease

Tumor-to-tumor metastasis in the central nerve system is uncommon in our routine practice. Most reports include metastatic breast cancer into meningioma. Here we report a metastatic clear cell renal cell carcinoma (ccRCC) into a cerebellar hemangioblastoma in a patient with von Hippel-Lindau (VHL) disease. Imaging cannot distinguish metastatic ccRCC from primary cerebellar hemangioblastoma. Immuno-molecular studies are proven to be diagnostic. We also reviewed previously documented tumor-to-tumor metastasis of ccRCC to cerebellar hemangioblastoma in VHL disease. Lastly, we discussed potential mechanisms involved in the metastasis of ccRCC to hemangioblastoma in the cerebellum in patients with VHL.

Meningioma and glioma as the first collision brain tumour reported in small animals

We describe the clinical and pathological features of a brain collision tumour consisting of a fibrous meningioma and an anaplastic oligoastrocytoma in a 14-year-old male neutered French Bulldog. Computed tomography of the brain revealed a poorly defined, intra-axial lesion affecting the left frontal lobe. Following euthanasia, histological examination showed an anaplastic oligoastrocytoma invading the brain parenchyma and an adjacent fibrous meningioma. As synchronous intracranial tumours are rare in animals, the aims of this report are to describe the clinical, imaging and histopathological features of an intracranial collision tumour in a dog and highlight the importance of a complete histopathological study despite the imaging findings.

Intracranial tumor-to-tumor metastasis in an elderly female: An unusual case report

Tumor-to-tumor metastasis is an extremely rare event, with only 150 reported cases in the literature. Meningioma, renal carcinoma, and tumors of the thyroid are the commonest sites of metastasis. Lung, breast, and GI-tract cancers are the most common types that undergo metastasis. Meningioma is the most common intracranial tumor as recipient of the tumor-to-tumor metastasis. Although breast carcinoma is the most common tumor to metastasize, adenocarcinoma from other organs can also spread to meningiomas, like the ovary and upper gastrointestinal (GI). We report a case of adenocarcinoma metastasis to meningioma with the possibility of primary involvement of the ovary or upper GI. A 77-year-old female patient presented to neurosurgery with episodes of multiple seizures and loss of consciousness. An MRI suggested a left frontotemporal meningioma. The patient underwent craniotomy with mass dissection. Microscopic examinations showed a dual tumor containing both components of meningioma with a metastatic adenocarcinomatous component. The tumor cells were positive for cytokeratin (CK7). Thus, the final diagnosis was made as meningothelial meningiomas (WHO grade I) with metastatic mucinous adenocarcinoma, possible primaries of the ovary or upper GI tract. The patient could not be followed up as we lost the patient a few days after surgery.

Case report: First case of early adenoid cystic carcinoma and squamous cell carcinoma collision cancer treated by endoscopic submucosal dissection

Background

Collision cancer, a rare tumor, rarely occurs in the esophagus. Most reported cases of esophageal collision cancers are advanced cancers that can only be treated with surgery or palliative chemoradiotherapy. Here, we report a rare case of collisional squamous cell carcinoma (SqCC) and adenoid cystic carcinoma (AdCC) that was detected in the early stages by endoscopy.

Case summary

A 66-year-old man presented with retrosternal pain after swallowing and underwent endoscopy. Pathological biopsy showed high-grade squamous intraepithelial neoplasia. The lesion was removed by endoscopic submucosal dissection (ESD) after magnification and endoscopic ultrasonography. Postoperative pathology proved that the lesion was collision cancer comprising SqCC and AdCC. After six months of postoperative follow-up, there was no recurrence of esophageal cancer.

Conclusions

We provided a case report related to the diagnosis and treatment of esophageal collision cancer, especially early collision cancer. More research is needed to provide insights into the management of collision cancers.

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.

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.

Diagnosis and clinical implication of collision gastric adenocarcinomas: a case report

BACKGROUND

Collision tumors are a subtype of simultaneous tumors wherein two unrelated tumors collide or infiltrate each other. Collision gastric adenocarcinomas (CGA) are rare and difficult to diagnose, and their clinical implications remain unclear. Herein, we aimed to reveal diagnostic methods for CGA and provide insight into its implications.

CASE PRESENTATION

Among 1041 cases of gastric cancers (GCs) resected between 2008 and 2018, we included cases of confirmed CGA. Patients' backgrounds, preoperative endoscopy findings, macroscopic imaging findings, and histopathology findings [including immunostaining for CK 7, MUC2, and mismatch repair (MMR) proteins] were investigated. The incidence of CGA was 0.5%: 5 of 81 cases having simultaneous multiple GCs. Tumors were mainly in the distal stomach. The CGA in two cases was between early cancers, in two cases was between early and advanced cancers, and in one case was between advanced cancers. There were three cases of collision between differentiated and undifferentiated types and two cases between differentiated types. Immunostaining with CK7 and MUC2 was useful for diagnosing collision tumor when the histology was similar to each other. Among ten GCs comprising CGA, nine tumors (90%) exhibited deficient MMR proteins, suggesting high microsatellite instability (MSI).

CONCLUSIONS

CGA is rare and usually found in the distal stomach. Close observation of shape, optimal dissection, and detailed pathological examination, including immunostaining, facilitated diagnosis. CGAs may have high MSI potential.

Cerebral meningioma associated with extensive calvarium osteolysis and presumed intratumoral carcinoma metastasis in a cat

Case summary

A 10-year-old male neutered domestic shorthair cat presented with a 3-month history of weight loss, dysorexia and lethargy. Neurological examination revealed decreased mentation, absent menace response bilaterally and proprioceptive deficits affecting all four limbs; these findings were consistent with a forebrain disorder. Brain CT revealed an extensive asymmetric permeative osteolysis destroying two-thirds of the circumference of the calvarium and involving the right frontal, parietal, temporal and occipital bones, as well as the left parietal bone. This extensive bone lysis was associated with a large ‘plaque-like’ extra-axial subdural/pachymeningeal lesion extending within the soft tissues surrounding the calvarium. The cat was humanely euthanased. Post-mortem MRI was performed, which revealed a T2-weighted (T2W) hypointense subdural lesion and a T2W hyperintense circumferential extracranial lesion lining the right calvarium and left parietal bone. Histopathological analysis on a post-mortem sample of the lesion revealed a fibroblastic subtype of meningioma. Epithelial neoplastic cells were observed scattered through the meningioma, calvarium and surrounding muscular tissues, corresponding with presumed metastatic carcinoma.

Relevance and novel information

To our knowledge, this is the first report of an intracranial meningioma associated with such an extensive and diffuse calvarial osteolysis in veterinary medicine. This is also the first description of presumed metastatic inclusions (adenocarcinoma in this case) inside an intracranial feline meningioma, which is a rare phenomenon known as tumour-to-tumour metastasis in human medicine.

Tumor-to-Tumor Metastasis: Renal Cell Carcinoma Metastasizing to a Lipoma of the Thigh: A Case Report

CASE

A 73-year-old man with a medical history significant for renal cell carcinoma (RCC) presented with widespread osseous metastases and imaging suspicious for RCC metastasizing to a lipoma interdigitated within the right vastus lateralis. The patient's pathological fractures were surgically addressed, and the lipoma excised. Final histology revealed a thigh lipoma involved by metastatic RCC without direct extension.

CONCLUSION

Tumor-to-tumor metastasis is a rare occurrence, with RCC typically being the most common "recipient" tumor. This is the first case to the best of our knowledge of RCC metastasizing to a lipoma, highlighting a rare phenomena in a patient with metastatic disease.

Tumor-to-tumor metastasis: an extremely rare combination with renal cell carcinoma as the donor and a pancreatic neuroendocrine tumor as the recipient

BACKGROUND

Tumor-to-tumor metastasis is a rare phenomenon in which primary tumor cells metastasize hematogenously into another tumor. Herein, we report an extremely rare case of a renal cell carcinoma metastasis into a pancreatic neuroendocrine tumor exhibiting a tumor-to-tumor metastasis. Ours is the third reported case worldwide.

CASE PRESENTATION

The patient, a 72-year-old male, was referred to our hospital for further examination and treatment due to high levels of prostate-specific antigen. A left renal tumor and pancreatic head tumor were revealed incidentally on screening computed tomography. There were suspected to be a renal cell carcinoma and primary pancreatic neuroendocrine tumor or pancreatic metastasis from the renal cell carcinoma according to preoperative examination. The left nephrectomy and subtotal stomach-preserving pancreaticoduodenectomy were performed because of the pancreatic tumor indicated for operation in either case of diagnosis. Postoperative pathological examination showed a diagnosis of clear cell renal cell carcinoma for the left renal tumor. The pancreatic tumor was diagnosed with clear cell renal cell carcinoma metastasis into the pancreatic neuroendocrine tumor, that is to say tumor-to-tumor metastasis.

CONCLUSION

In some cases, conservative approach is selected for pancreatic neuroendocrine tumor patients who meet some requirements. However, if such patients exhibit tumor-to-tumor metastasis which combines with renal cell carcinoma and pancreatic neuroendocrine tumor as this case, conservative approach leads to progression of renal cell carcinoma. Therefore, conceiving the possibility of tumor-to-tumor metastasis, it is necessary to carefully choose a treatment plan for pancreatic neuroendocrine tumor patients associated with renal cell carcinoma, not easily choosing conservative approach.

Tumor-to-tumor metastases: latent renal cell carcinoma discovered after elective surgical resection of a convexity meningioma

BACKGROUND

Tumor-to-tumor metastases are extremely rarely reported lesions which usually involve an indolent lesion hosting a more aggressive neoplasm. We present an unusual initial manifestation of a previously unknown clear cell renal cell carcinoma as a tumor-to-tumor metastasis in a typical meningothelial meningioma.

CASE REPORT

A 73-year old patient with transient left slight monoparesis was addressed to our Neurosurgical Department after being evaluated by his general practitioner and passing a cerebral MRI which revealed a right frontotemporal mass attached to the meninge. At presentation, no deficits were identified; therefore an elective surgery was proposed. Histological analysis revealed a typical meningothelial meningioma containing a metastatic clear cell renal cell carcinoma. Additional thoraco-abdominal computer tomography identified a 6 cm diameter lesion within the right kidney with radiological features highly suggestive of a primary clear cell renal cell carcinoma.

CONCLUSION

Our case highlights the need for a specialized neuropathological approach to clinical and imagistic indolent meningiomas, as they may require important differential diagnosis that can highly impact the treatment and follow-up of brain tumor patients.

Pituitary metastasis: From pathology to clinical and radiological considerations

PURPOSE

A review of the literature with respect to pituitary metastases (PM) with clinical and radiological considerations are summarized to facilitate clinical decision making in the management of PM METHODS: A review of literature associated with PM and tumour to tumour metastases in the English literature was reviewed and summarized RESULTS: Pituitary metastases account for 1.0-3.6% of all surgically treated pituitary lesions. Often identified in parallel with extensive disseminated disease, once diagnosed, the prognosis is generally poor, although survival is highly heterogeneous and dependent on the primary tumor histology. Within this anatomical region is also the observation of tumor-to-tumor metastases and collision tumours. Both the tumor macro- and microenvironment play central roles to the progression of disease with distinctive radiological features that may suggest a metastatic sellar lesion as opposed to a primary pituitary lesion. Surgical resection is the first line of therapy followed by adjuvant chemoradiotherapy and endocrinological evaluation for hormonal supplementation CONCLUSION: PMs are relatively rare but important oncological entities representing disseminated disease in the majority of cases. Careful consideration of the relevant clinical history and radiological features can aid the clinician differentiate between a metastatic lesion to the pituitary region and a primary pituitary tumor. While surgical resection is first line therapy, stereotactic radiosurgery in carefully selected patients is emerging as a viable alternative.

Intrameningioma metastasis: A case-based literature review

A tumor-to-tumor metastasis inside a meningioma is a rare phenomenon. Malignant neoplasms of the breast and lung are the most common primary tumors. Other sites of origin include prostate, renal and gastric neoplasms. The included case files were retrieved from the medical records of the University Hospital of Crete, Greece. A review of the literature was conducted in March 2020 via PubMed. Relevant search results were few. We report a case of a 66-year-old female, with known Small Cell Lung Cancer, who presented with left-sided hemiparesis. The Magnetic Resonance Imaging scan revealed a right frontal extra-axial mass. The patient underwent a craniotomy and a gross total removal of the tumor. Histological examination of the excised mass revealed metastatic adenocarcinoma deposits inside a meningioma: tumor-to-tumor metastasis. Reviewing the available literature, it has been hypothesized that the following factors play a role in the pathophysiology of this phenomenon: progesterone and estrogen receptors, cell-to-cell adhesion molecules, rich vascularization, favorable metabolic, micro-and immunological environment. Meningiomas seem to be the most common type of intracranial neoplasm to host a metastasis. There is a difference between tumor-to-tumor metastasis and collision tumors. The former implies a recipient role of the host tumor, and the latter refers to a co-localization of two different tumors that grow into one another, both being in the same organ. Tumor-to-tumor brain metastasis is a well-described phenomenon but with unclear pathophysiology. Deeper knowledge could be beneficial for its management.

A collision tumor of solitary fibrous tumor/hemangiopericytoma and meningioma: A case report with literature review

An intracranial collision tumor is a rare lesion composed of two histologically different neoplasms in the same anatomic location. Even more rare is the collision tumor of a solitary fibrous tumor/hemangiopericytoma (SFT/HPC) and meningioma. The patient was a 46-year-old woman who had a 40 × 35 × 30-mm mass in the vermis of the cerebellum. Histologically, the mass consisted of two different components. One component showed the morphology of meningioma (World Health Organization (WHO) grade I), and the other component exhibited small round cell proliferation with hypercellular density, which was revealed to be SFT/HPC (WHO grade III) based on STAT6 immunohistochemistry. STAT6 showed completely different immunohistochemistry results in these two components (nuclear-negative in meningioma and nuclear-positive in SFT/HPC). Since these two neoplasms are associated with different prognoses, they should be distinguished from each other. When meningioma and an SFT/HPC-like lesion are identified morphologically, it is important to recognize the presence of such a collision tumor composed of meningioma and SFT/HPC, and identify the SFT/HPC component by employing STAT6 immunohistochemistry.

Temozolomide Induces the Acquisition of Invasive Phenotype by O6-Methylguanine-DNA Methyltransferase (MGMT)+ Glioblastoma Cells in a Snail-1/Cx43-Dependent Manner

Glioblastoma multiforme (GBM) recurrences after temozolomide (TMZ) treatment result from the expansion of drug-resistant and potentially invasive GBM cells. This process is facilitated by O6-Methylguanine-DNA Methyltransferase (MGMT), which counteracts alkylating TMZ activity. We traced the expansion of invasive cell lineages under persistent chemotherapeutic stress in MGMT^low (U87) and MGMT^high (T98G) GBM populations to look into the mechanisms of TMZ-induced microevolution of GBM invasiveness. TMZ treatment induced short-term, pro-invasive phenotypic shifts of U87 cells, in the absence of Snail-1 activation. They were illustrated by a transient induction of their motility and followed by the hypertrophy and the signs of senescence in scarce U87 sub-populations that survived long-term TMZ stress. In turn, MGMT^high T98G cells reacted to the long-term TMZ treatment with the permanent induction of invasiveness. Ectopic Snail-1 down-regulation attenuated this effect, whereas its up-regulation augmented T98G invasiveness. MGMT^low and MGMT^high cells both reacted to the long-term TMZ stress with the induction of Cx43 expression. However, only in MGMT^high T98G populations, Cx43 was directly involved in the induction of invasiveness, as manifested by the induction of T98G invasiveness after ectopic Cx43 up-regulation and by the opposite effect after Cx43 down-regulation. Collectively, Snail-1/Cx43-dependent signaling participates in the long-term TMZ-induced microevolution of the invasive GBM front. High MGMT activity remains a prerequisite for this process, even though MGMT-related GBM chemoresistance is not necessary for its initiation.

Metastases to meningioma-review and meta-analysis

PURPOSE

Meningiomas are a common tumor within the cranial cavity. They may be a target for metastatic spread of cancer elsewhere in the body. We analyzed all the data in the literature about tumor-to-meningioma metastasis (TTMM).

METHODS

We performed a meta-analysis using the PRISMA checklist to locate all cases of TTMM in the PubMed and Medline databases. We collected patient and cancer parameters, meningioma parameters, and clinical factors.

RESULTS

We located 124 articles, describing 152 cases of patients with TTMM. The mean (± SD) age of all patients was 62.21 ± 10.8 years, with even distribution above and below the mean. Of the cases, 65.9% were reported in women. The most common cancer origins of TTMM were breast and lung carcinoma, followed by kidney, prostate, and GI tract carcinoma. Cancer status is not a good marker of TTMM when managing a meningioma. In 36.69% of cases, TTMM was the presentation of an unknown cancer. In nearly 60% of the known cases, cancer was considered in remission for at least 1 year. Meningioma parameters are unhelpful when considering a TTMM. The distribution of meningioma location is similar to other series of meningioma reported in the literature. Meningioma grade is similar to meningiomas without TTMM. In 57.89%, the patient presented with a focal deficit. Presenting factors were seizures, elevated ICP, and others. Over 95% of cases were symptomatic at presentation.

CONCLUSION

TTMM should be suspected in cases of meningioma in a patient with background cancer, regardless of meningioma parameters or cancer status.

Coexistence of craniopharyngioma and meningioma: Two rare cases and literature review

Most of the craniopharyngioma is considered to derive from residual epithelial cells during the craniopharyngeal canal degeneration. Meningioma accounting for the primary intracranial neoplasm is considered to be mainly derived from cells of arachnoid granulations. Nevertheless, rare cases show coexistence of craniopharyngioma and meningioma.Case 1: A 43-year-old male patient referred to the hospital due to paroxysmal headache combined with blurred vision for 1 month. On physical examination, the visual acuity of left eye was poorer than that of the right eye. The visual acuity of the right eye near the nasal part showed defect.MRI and pathological examination were performed. The patient received intracranial tumor resection. After surgery, the patient showed hormone disorder, followed by corresponding treatment. However, the patient was lost in the 6-month follow-up.Case 2: The 64-year-old male patient presented to our department due to decline of visual acuity within 1 year combined with polydipsia (5,000 ml per day), polyuria and fatigue for 6 months. On physical examination, the bilateral visual acuity showed decline, especially the temporal part which was nearly hemiscotosis. MRI was performed. The adamantinomatous craniopharyngioma was diagnosed with the HE staining findings. The patient received intracranial resection. After surgery, the patient was in a deep coma condition, and was lost in the follow-up.In this case study, we presented 2 patients with coexistence of craniopharyngioma and meningioma. In addition, a complete literature review was carried out to illustrate the studies on coexistence of craniopharyngioma and meningioma. Meanwhile, we tried to explain the possible mechanisms for such condition.

Collision tumors of the lung: A case report of urothelial carcinoma metastasizing to renal cell carcinoma with heterotopic ossification

Collision tumors are rare entities that consist of at least two or more histologically and ontologically distinct tumor types within the same organ. It is still not well understood how collision tumors form; yet, three main theories have been proposed to explain the pathogenesis, including the “random collision effect,” “field cancerization,” and “tumor-to-tumor carcinogenesis.” Collision tumors have been encountered in various body organs, including the lung. They either consist of a metastasizing tumor colliding with primary cancer or distinct primary or metastatic cancers colliding together. Here, we describe a rare case of collision tumors of the lung that consists of two metastatic carcinomas, namely renal cell carcinoma and urothelial carcinoma of the bladder. We propose that the urothelial carcinoma disseminated into several pre-existing pulmonary metastases of renal cell carcinoma with heterotopic bone formation. The possible mechanisms underlying the development of this peculiar tumor are discussed.

Metastasis of pulmonary adenocarcinoma to right occipital parafalcine meningioma: A case report and literature review

RATIONALE

Tumor-to-tumor metastasis is a rare clinical phenomenon. Although meningioma is the most common intracranial recipient of cancer metastasis, only a few cases have been reported. We present a case of metastasis of lung adenocarcinoma into intracranial meningioma and review the published literature.

PATIENT CONCERNS

A 70-year-old woman was admitted to our hospital for a 1-month history of headache and pain in her lower extremities.

DIAGNOSIS

Brain and lumbar vertebral magnetic resonance imaging showed an intracranial space-occupying lesion in the right occipital region and spinal canal stenosis. Pulmonary computed tomography showed an irregular mass in the right upper lobe of the lung. The postoperative histological examination demonstrated adenocarcinoma metastasis to meningioma.

INTERVENTION

The patient underwent right occipital craniotomy for tumor removal and lumbar spinal canal decompression.

OUTCOMES

There were no initial abnormal conditions after the operation. However, the patient died suddenly 7 days after surgery.

LESSONS

Tumor-to-meningioma metastasis is a rare but important phenomenon. According to previous reports, it is associated with rapid onset of symptoms and a poor prognosis. Histological examination is of great importance in diagnosis. The history and process of malignant carcinoma should be closely monitored.

A Rare Intracranial Collision Tumor of Meningioma and Metastatic Uterine Adenocarcinoma: Case Report and Literature Review

BACKGROUND

A collision tumor is a rare entity consisting of 2 histologically distinct tumor types (benign or malignant) in the same anatomic location. This can occur from a tumor-to-tumor metastasis or as a result of 2 adjacent intracranial tumors colliding and growing together. To our knowledge, this is the first reported case of collision tumor with confirmed meningioma and uterine adenocarcinoma. Multiple mechanisms have been proposed for the facilitative growth of collision tumors, including local epigenetic signaling. Clinically, it is important to consider collision tumors in the differential diagnosis of a rapidly growing intracranial lesion in the setting of systemic cancer to provide optimal surgical and postoperative management.

CASE DESCRIPTION

A 78-year-old, right-handed woman with a known 10-year history of stable meningioma presented for evaluation of a right sphenoid wing lesion. She had recently completed treatment of uterine papillary serous carcinoma with no evidence of disease on follow-up imaging. On presentation, there was significant progression of the meningioma resulting in brain compression and right third nerve palsy. The patient underwent urgent resection of the lesion. Pathology demonstrated a collision tumor with a combination of metastatic uterine papillary serous carcinoma and meningioma.

CONCLUSIONS

It is important to consider a collision tumor when a patient with a benign intracranial lesion presents with rapid progression, even in the context of a systemic cancer that rarely metastasizes to the brain. Appropriate histopathologic assessment is crucial in these cases and can have a significant impact on treatment plan and prognosis.

Rare Tumor-to-Tumor Metastases Involving Lung Adenocarcinoma to Petroclival Meningiomas

BACKGROUND

Lung carcinoma metastasizing to a skull base meningioma remains an extremely rare phenomenon, with only 3 studies reported. Furthermore, no documented cases have been reported in the petroclival region. Thus, we have presented the first 2 cases of tumor-to-tumor metastasis (TTM) in which a petroclival lesion, initially thought to be purely meningioma, was also found to contain metastatic lung adenocarcinoma.

CASE DESCRIPTION

We present the cases of 2 patients with a known history of lung adenocarcinoma and stable petroclival meningioma who had presented with new-onset neurologic deficits. Repeat imaging studies for both patients found an increased lesion size and peritumoral enhancement; thus, both patients underwent emergent craniotomy for complete lesion resection. Intraoperatively, both lesions had zones of markedly different tumoral texture. On histologic analysis, both lesions showed metastatic lung adenocarcinoma contained within the primary petroclival meningioma.

CONCLUSION

Skull base TTM is a rare entity for which no specific management guidelines have been created. Therefore, even if the imaging characteristics suggest a more benign process, skull base TTM should remain high on the differential diagnosis for patients with a known primary cancer and new-onset, rapidly progressive, neurologic deficits. Close clinical follow-up with short-interval repeat imaging in this subset of patients might prevent misdiagnosis and facilitate prompt treatment.

Lymphoma Metastasis to Vertebral Body Hemangioma: Collision Tumor Causing Cord Compression

BACKGROUND

Collision tumors of the spine are extremely uncommon. Prior reports have detailed intracranial collision tumors comprising meningiomas and astrocytomas, as well as metastases to meningiomas. Spinal collision tumors are even rarer, with only 5 cases in the literature, none involving the osseous spine. In this report, we highlight the salient features of a case of lymphoma metastasis to a preexisting benign osseous hemangioma, resulting in cord compression.

CASE DESCRIPTION

An 81-year-old woman with a known typical T8 vertebral body hemangioma stable for over 6 years was evaluated for increasing back pain, new gait instability, and urinary retention. Magnetic resonance imaging showed a change in the appearance of the T8 hemangioma, with marrow replacement and new associated epidural soft tissue causing cord compression. A biopsy was performed, which showed diffuse large B-cell lymphoma within blood elements, consistent with lymphoma metastasis to a vertebral body hemangioma. The patient was treated with intravenous steroids and radiation therapy.

CONCLUSIONS

Collision tumors of the spine are extremely rare. New or increasingly aggressive appearance of a previously benign spinal osseous lesion should prompt consideration for a collision tumor or malignant transformation of the benign tumor. Biopsy of the lesion should be strongly pursued whenever feasible, as the treatment strategy may vary depending on the histology of the tumor.

Lung adenocarcinoma metastasizing to fibrous histiocytoma: A case report

RATIONALE

Tumor-to-tumor metastasis is an uncommon phenomenon, and the tumor metastatic to mesenchymal tumor is extremely rare. To our knowledge, this is the first case of lung adenocarcinoma metastasizing to fibrous histiocytoma.

PATIENT CONCERNS

A 58-year-old Chinese woman was admitted to our hospital with a complaint of progressive enlargement of a mass in the right upper arm without pain, heat (localized warmth), redness, and swelling, for a year.

DIAGNOSES

Ultrasound revealed a mass with relative clear boundary in the right upper arm near elbow joint. Uneven echoes, and blood flow signals were showed within the mass. The tumor was well-demarcated from the surrounding tissue a thin fibrous capsule. Scattered enlarged cells with hyperchromatic pleomorphic nuclei were dispersed in an otherwise typical cutaneous fibrous histiocytoma. These atypical cells arranged in poorly glandular structures or irregular epithelioid nest and were demonstrated as metastatic lung adenocarcinoma by immunohistochemical staining. We reviewed the biopsy section and found these 2 sites of adenocarcinoma shared similar histologic morphological features. Therefore, the final diagnosis was lung adenocarcinoma metastasizing to fibrous histiocytoma.

INTERVENTIONS

The patient was diagnosed with lung adenocarcinoma by bronchoscopic biopsy 3 months ago and received 4 cycles of NP (Vinoreltraye [NVB] + cis-platinum) chemotherapy program. The patient underwent a total resection of the mass in right upper arm.

OUTCOMES

The patient died of multiple organ failure after 10 months since she was diagnosed as lung adenocarcinoma.

LESSONS

The accumulation of lipid droplets in fibrous histiocytoma may be a potential reason for modifying pre-metastatic niche, and therefore create a tumor microenvironment suitable for metastasis.