Surgical Management of a Collision Tumor: The Association of Intracranial Meningioma and Macroadenoma

Background: The simultaneous presence of a pituitary adenoma and a meningioma is a rare and underreported condition. The randomly encountered cases need to be reported to further allow our understanding of this collision tumors that are still not understood nor fully described. Patients and Method: We report a case of coexisting nonfunctioning pituitary adenoma and a left temporal lobe meningioma revealed by a 1-year history of progressive vision loss and occasional headaches in a 56-year-old woman. Her clinical condition worsened in the last 5 months with ptosis, cavernous sinus syndrome, and ophthalmoplegia of the right eye without papilledema. There was an improvement in the visual symptoms after subtotal resection of both lesions through a right frontotemporal craniotomy. Histology confirmed a collision tumor. The patient was referred for adjuvant treatment with gamma knife radiosurgery. He was doing well and back to his usual duties 6 months later. Conclusion: A gross total or subtotal resection with adjuvant therapy is the gold standard for the surgical management of collision tumors for a favorable patient outcome.

Ovarian-adnexal reporting and data system ultrasound evaluation and pathological characteristics of ovarian collision tumor

BACKGROUND Collision tumor are neoplasms,including two histologically distinct tumors that coexist in the same mass without histological admixture.The incidence of collision tumor is low and is rare clinically.AIM To investigate ultrasound images and application of ovarian-adnexal reporting and data system(O-RADS)to evaluate the risk and pathological characteristics of ovarian collision tumor.METHODS This study retrospectively analyzed 17 cases of ovarian collision tumor diagnosed pathologically from January 2020 to December 2023.All clinical features,ultrasound images and histopathological features were collected and analyzed.The O-RADS score was used for classification.The O-RADS score was determined by two senior doctors in the gynecological ultrasound group.Lesions with O-RADS score of 1-3 were classified as benign tumors,and lesions with O-RADS score of 4 or 5 were classified as malignant tumors.RESULTS There were 17 collision tumors detected in 16 of 6274 patients who underwent gynecological surgery.The average age of 17 women with ovarian collision tumor was 36.7 years(range 20-68 years),in whom,one occurred bilaterally and the rest occurred unilaterally.The average tumor diameter was 10 cm,of which three were 2-5 cm,11 were 5-10 cm,and three were>10 cm.Five(29.4%)tumors with O-RADS score 3 were endometriotic cysts with fibroma/serous cystadenoma,and unilocular or multilocular cysts contained a small number of parenchymal components.Eleven(64.7%)tumors had an O-RADS score of 4,including two in category 4A,six in category 4B,and three in category 4C;all of which were multilocular cystic tumors with solid components or multiple papillary components.One(5.9%)tumor had an O-RADS score of 5.This case was a solid mass,and a small amount of pelvic effusion was detected under ultrasound.The pathology was high-grade serous cystic cancer combined with cystic mature teratoma.There were nine(52.9%)tumors with elevated serum carbohydrate antigen(CA)125 and two(11.8%)with elevated serum CA19-9.Histological and pathological results showed that epithelial-cell-derived tumors combined with other tumors were the most common,which was different from previous results.CONCLUSION The ultrasound images of ovarian collision tumor have certain specificity,but diagnosis by preoperative ultrasound is difficult.The combination of epithelial and mesenchymal cell tumors is one of the most common types of ovarian collision tumor.The O-RADS score of ovarian collision tumor is mostly≥4,which can sensitively detect malignant tumors.

Ileal collision tumor associated with gastrointestinal bleeding: A case report and review of literature

BACKGROUND Collision tumors involving the small intestine,specifically the combination of a hamartomatous tumor and a lipoma,are extremely rare.To our knowledge,no previous case report has described a collision tumor composed of two benign tumors of different origins in the small intestine.CASE SUMMARY Here,we present the case of an 82-year-old woman who presented with hemorrhagic shock and was found to have a mass measuring approximately 50 mm×32 mm×30 mm in the terminal ileum.Based on computed tomography scan findings,the mass was initially suspected to be a lipoma.A subsequent colonoscopy revealed a pedunculated submucosal elevation consisting of two distinct parts with a visible demarcation line.A biopsy of the upper portion suggested a juvenile polyp(JP).Owing to the patient’s advanced age,multiple comorbidities,and poor surgical tolerance,a modified endoscopic submucosal dissection was performed.Histopathological examination of the excised mucosal mass revealed a lipoma at the base and a JP at the top,demonstrating evidence of rupture and associated bleeding.The patient’s overall health remained satisfactory,with no recurrence of hematochezia during the six-month follow-up period.CONCLUSION This case report provides new evidence for the understanding of gastrointestinal collision tumors,emphasizing their diverse clinical presentations and histopathological characteristics.It also offers diagnostic and therapeutic insights as well as an approach for managing benign collision tumors.

Collision tumor of primary malignant lymphoma and adenocarcinoma in the colon diagnosed by molecular pathology:A case report and literature review

BACKGROUND Collision tumors of primary malignant lymphoma and adenocarcinoma in the colon are rare.Primary diffuse large B-cell lymphoma(DLBCL)–adenocarcinoma collision tumors are especially rare.CASE SUMMARY A 74-year-old woman presented with abdominal pain of 1 mo duration.Biopsy under colonoscopy revealed adenocarcinoma of the ascending colon.Subsequently,the patient underwent laparoscopic radical resection of right colon cancer with lymph node dissection.A collision tumor was found incidentally through postoperative pathological sampling.Genetic analysis showed a collision tumor of DLBCL with germinal center B-cell subtype and TP53 mutation,and adenocarcinoma arising in a tubulovillous adenoma in the colon,with BRAF mutation and mutL homolog 1 promoter methylation.The patient died 3 mo after surgery.To our knowledge,this is the 23rd reported case of collision tumor of colorectal adenocarcinoma and lymphoma.The mean age of the 23 patients was 73 years.The most common site was the cecum.There were 15 cases with followup data including 11 living and four dead with a 3-year overall survival rate of 71.5%.CONCLUSION Based on pathological and genetic analysis,surgery combined with chemotherapy or chemoradiotherapy may have good therapeutic effects for collision tumor.

Collision tumor of hepatocellular carcinoma and neuroendocrine carcinoma involving the liver: Case report and review of the literature

Primary hepatic neuroendocrine carcinoma(NEC) with concurrent occurrence of hepatocellular carcinoma(HCC) of the liver is very rare. Only 8 cases have been reported in the literature. Concurrent occurrence of HCC and NEC in the liver is classified as combined type or collision type by histological distributional patterns; only 2 cases have been reported. Herein, we report a case of collision type concurrent occurrence of HCC and NEC, in which primary hepatic NEC was in only a small portion of the nodule, which is different from the 2 previously reported cases. A 72-year-old male with chronic hepatitis C was admitted to our hospital for a hepatic mass detected by liver computed tomography(CT) at another clinic. Because the nodule was in hepatic segment 3 and had proper radiologic findings for diagnosis of HCC, including enhancement in the arterial phase and wash-out in the portal and delay phases, the patient was treated with laparoscopic left lateral sectionectomy. The pathology demonstrated that the nodule was 2.5 cm and was moderately differentiated HCC. However, a 3 mm-sized focal neuroendocrine carcinoma was also detected on the capsule of the nodule. The tumor was concluded to be a collision type with HCC and primary hepatic NEC. After the surgery, for follow-up, the patient underwent a liver CT every 3 mo. Five multiple nodules were found in the right hepatic lobe on the follow-up liver CT 6 mo post-operatively. As the features of the nodules in the liver CT and MRI were different from that of HCC, a liver biopsy was performed. Intrahepatic recurrent NEC was proven after the liver biopsy, which showed the same pathologic features with the specimen obtained 6 mo ago. Palliative chemotherapy with a combination of etoposide and cisplatin has been administered for 4 months, showing partial response.

Collision tumor of the rectum: A case report of metastatic gastric adenocarcinoma plus primary rectal adenocarcinoma

Collision tumors are thought to arise from the accidental meeting and interpenetration of two independent tumors. We report here a highly unusual case of a 61-year old man who had a unique tumor that was composed of a metastatic adenocarcinoma from the stomach to the rectum, which harbored a collision tumor of primary rectal adenocarcinoma. The clonalities of the two histologically distinct lesions of the rectal mass were confirmed by immunohistochemical and molecular analysis. Although histologic examination is the cornerstone in pathology, immunohistochemical and molecular analysis can provide evidence regarding whether tumors originate from the same clone or different clones. To the best of our knowledge, this is the fi rst reported case of such an occurrence.

Collision tumor of squamous cell carcinoma and neuroendocrine carcinoma in the head and neck:A case report

BACKGROUND There are many disputes about the definition,diagnosis,therapy,and prognosis of collision tumors.CASE SUMMARY We describe a rare patient with a collision tumor consisting of neuroendocrine carcinoma(NEC)and squamous cell carcinoma(SCC)in the nasal cavity and paranasal sinus.She received operation,concurrent chemoradiotherapy,and then two cycles of palliative chemotherapy.Follow-up at 12 mo after diagnosis showed that this patient experienced a complete response with no signs of recurrence or metastasis.A literature review of previous 26 cases diagnosed with collision tumor of NEC and SCC in the head and neck was also undertaken.CONCLUSION It is challenging to manage collision tumors because there are two morphologically and etiologically distinct tumors.Well-designed multimodality therapy including surgery and chemoradiotherapy might lead to a long survival in these patients.

Liver collision tumor of primary hepatocellular carcinoma and neuroendocrine carcinoma:A rare case report

BACKGROUND Hepatocellular carcinoma(HCC)can occasionally develop with other non-HCC cell types,either in a combined type or collision type.A collision tumor is defined as two histopathologically distinct tumors of the same organ lacking a clear transition zone.Hepatic collision tumors are rare.Among them,“hepatocellular carcinoma-hepatic neuroendocrine carcinoma”(HCC-NEC)collision tumors are especially rare and information about them is rarely published.CASE SUMMARY A 48-year-old man with typical findings of HCC underwent consecutive therapies,including radiofrequency ablation and embolization prior to resection.Diagnosis of the HCC-NEC collision tumor in the right liver and another HCC in the left liver was established following surgical resection.The patient displayed NEC metastasis following resection and succumbed to septicemia after 2 more rounds of chemotherapy.To our knowledge,this is the 25th reported case of mixed HCC-NEC tumor.The rarity of HCC-NEC collision tumors and the absence of diagnostic criteria make it difficult to differentiate this condition from simple liver tumors,especially in patients with chronic liver disease.CONCLUSION Our case highlights the difficulty in accurately diagnosing HCC-NEC in the absence of histological evidence.The prognosis is poor for this condition,although ultrasound-guided liver biopsy can be helpful to establish a prompt diagnosis.Further accumulation of such cases could help establish an accurate diagnosis earlier.Early discovery of NEC may allow for better treatment strategies and better prognoses.

Gastric Collision Tumor of Adenocarcinoma and MALT Lymphoma: A Rare Coincidence or Proof of H. pylori Incrimination?

Collision tumors of adenocarcinoma and MALT (Mucosa-associated lymphoid tissue) lymphoma are often rare findings of resection specimens of gastric carcinomas. The fact that these two histological lesions are contiguous may suggest a common oncogene. As it is widely known, Helicobacter pylori (H. pylori) plays a leading role in gastric oncogenesis. Could it be responsible for these tumors? As of today, the exact mechanism is still unclear. However, some histological findings may suggest that H. pylori promotes the formation of MALT lymphoma which increases the risk of carcinomatous changes. Prognosis of collision tumors is tightly linked to the carcinoma lesion, which is generally poor due to diagnostic delay. Large scale strategies to eradicate H. pylori and detect early lesions could reduce the mortality of this disease.

Solitary concomitant endocrine tumor and ductal adenocarcinoma of pancreas

Pancreatic tumors with combined exocrine and endocrine features are rare.Most reported cases are classified as mixed exocrine and endocrine carcinoma of the pancreas.We report the first case of solitary concomitant endocrine tumor and ductal adenocarcinoma of the pancreas.A 58-year-old patient was admitted for uncontrolled diabetes mellitus and body weight loss.The tumor was fortuitously discovered in the pancreatic tail after a tumor survey panel.Grossly,the solitary tumor had a central fibrous band that clearly divided it into two parts.On microscopic examination,the tumor contained both endocrine and exocrine components distinctly separated by the central fibrous band.The exocrine part showed a poorly-differentiated adenocarcinoma.The endocrine part was strongly immunoreactive to chromogranin,synaptophysin and glucagon.We reviewed the literature on pancreatic tumors with combined exocrine and endocrine features.A simple classification for this group of neoplasms is suggested,including five types:amphicrine,mixed,collision,solitary concomitant and multiple concomitant.

Mixed pancreatic ductal adenocarcinoma and well-differentiated neuroendocrine tumor:A case report

BACKGROUND Pancreatic mixed neuroendocrine-non-neuroendocrine neoplasms(MiNENs)are rare malignancies affecting the pancreas.The World Health Organization defines MiNENs as neoplasms composed of morphologically recognizable neuroendocrine and non-neuroendocrine components,each constituting 30%or more of the tumor volume.Adenocarcinoma-neuroendocrine carcinoma is the most frequent MiNEN combination.A well-differentiated neuroendocrine tumor(NET)component is rarely reported in MiNENs.CASE SUMMARY Here we report a rare case with intermingled components of ductal adenocarcinoma and grade 1 well-differentiated NET in the pancreas.The two tumors show distinct histology and significant differentiation discrepancy(poorly differentiated high grade adenocarcinoma and well-differentiated low grade NET),and also present as metastases in separate lymph nodes.Next generation sequencing of the two components demonstrates KRAS and TP53 mutations in the ductal adenocarcinoma,but no genetic alterations in the NET,suggesting divergent origins for these two components.Although tumors like this meet the diagnostic criteria for MiNEN,clinicians often find the diagnosis and staging confusing and impractical for clinical management.CONCLUSION Mixed NET/non-NET tumors with distinct histology and molecular profiles might be better classified as collision tumors rather than MiNENs.

Collision nodal metastasis of bladder cancer and melanoma:The first reported case and literature review

Collision metastasis is a rare phenomenon of concomitant localization of 2 or more different tumors in the same lymph node.In most cases,primary malignancies are synchronous carcinomas arising in the same organ or area of the body.A 82-year-old man presented with hematuria and acute renal failure;he had undergone dermatological consultation ten months ago because of a large deep brown skin lesion in his dorso-lumbar region,which was not excised upon patient's request.He underwent radical cystectomy with extended pelvic lymphadenectomy due to nonpapillary high-grade urothelial carcinoma,with focal squamous features,infiltrating the bladder wall and prostate gland.In one left iliac lymph node,small foci of metastatic urothelial carcinoma(positive for P63 and CK34betaE12)were close to melanoma cells(positive for HMB45).The patient refused further treatment and died of metastatic disease 12 months after cystectomy.There is no specific clinical feature for nodal collision metastasis.A polymorphic histologic appearance poses the suspect,but immunohistochemical stains are needed to define the primary tumors.Collision metastases are thought to carry a poor prognosis.Their clinical relevance is linked to the fact that the patient faces 2 different metastatic tumors that may require specific multidisciplinary approach once diagnosed as metastatic.We present,to the best of our knowledge,the first case of collision nodal metastasis from bladder cancer and melanoma,and describe its clinical and histopathological characteristics to raise awareness on this rare occurrence,which portends a poorer prognosis than each single tumor.

Occult Renal Cell Carcinoma of Eosinophilic Morphology Detected within Renal Angiomyolipoma Mass in a Patient with Tuberous Sclerosis Complex

The kidney is affected in about 80-85% of tuberous sclerosis complex （TSC） patients. Renal manifestations in TSC patients include an increased incidence of epithelial cysts and tumors, such as multiple renal angiomyolipomas （AMLs）, renal cell carcinoma （RCC）, and oncocytoma. The coexistence of RCC and renal AML within same tumor masses, namely collision tumor, is very rare, and about six cases have been reported. Here, we present a case of a young male with TSC and multiple AMLs, containing RCC with eosinophilic morphology.