Colorectal carcinoma to pituitary tumour: tumour to tumour metastasis

We document a patient with colon adenocarcinoma who presented with rapidly worsening visual impairment. Staging computer tomography and subsequent magnetic resonance scans documented a sellar, suprasellar lesion compressing the optic chiasm. The patient underwent trans-sphenoidal surgery to relieve optic chiasm compression and obtain tissue for diagnosis. Histological examination revealed a metastatic mucinous adenocarcinoma in a gonadotroph pituitary neuroendocrine tumour (PitNET, formerly pituitary adenoma). The patient underwent adjuvant radiotherapy to the sella and chemotherapy but he died nine months after pituitary surgery. This report highlights the diagnostic and management challenges of metastases to PitNET.

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.

Collision Tumor of the Appendix

This report discusses the case of a 20-year-old female patient who presented with acute abdominal pain, nausea, and vomiting. Initial laboratory analyses suggested an inflammatory process, but imaging studies failed to reveal pathologies. The patient underwent a diagnostic laparoscopy, which showed a thickened and multicystic appendix with signs of acute inflammation. Pathology indicated a positive cytology for malignancy, with a grade 1 mixed well-differentiated neuroendocrine tumor (NET) and high-grade mucinous neoplasm identified in the middle and distal thirds of the appendix. Finding both tumors in the same patient is extremely rare and has been reported in a few cases. The case emphasizes the importance of considering appendiceal tumors in the differential diagnosis of acute abdominal pain, even in young patients, and highlights the value of laparoscopy in their diagnosis. The early detection and appropriate management of appendiceal tumors are crucial for improving patient outcomes.

Squamomelanocytic Tumors: A Singular Case Report and Comprehensive Review

Cutaneous neoplasms from different cell types can exist within the same lesion. These can be classified into four subtypes which are collision tumour, combined tumour, colonization and biphenotypic tumour. The presence of a melanoma component in these tumours is very rare. Herein we present a singular case of two synchronous dineoplastic cutaneous tumours: a squamomelanocytic tumour and a collision consisting of melanoma and seborrheic keratosis. Additionally, we performed a literature review of all squamomelanocytic tumours published until date, including our case.

A Rare Case of Collision Tumours of the Ovary: An Ovarian Serous Cystadenoma Coexisting with Fibrothecoma

The incidence of epithelial tumours of the ovary ranges from 9-17 per 100,000 and is the highest in high-income countries, with the exception of the Japan. The coexistence of neoplastic Müllerian epithelial and sex cord-stromal elements within a single tumour is extremely rare. We describe the case of a 74-year-old woman with a voluminous left adnexal formation. Pre-operative assessment with ultrasound evaluation made a suspicious diagnosis of benignity of the lesion. Bilateral salpingo-ovariectomy was performed. Intraoperative frozen section analysis results in the diagnosis of fibrothecoma in the context of serous cystadenoma. The diagnosis is confirmed by histological examination. Some authors suggest labelling this phenomenon as collision tumours.

First Report of a Paediatric Collision Tumour in the Liver Recognised After Liver Transplantation: Blissful Ignorance Has Benefits!

Liver tumours are uncommon in the paediatric population, constituting 1-2 % of all paediatric tumours and 4% of all paediatric liver tumours. Hepatoblastoma followed by hepatocellular carcinoma is the most common tumours in this age group. Simultaneous development of two discrete liver tumours of distinct histologies (collision tumour) has been occasionally reported in adults but never in children. We hereby present the first reported case of hepatic collision tumours (hepatocellular carcinoma and cholangiocarcinoma) in the explant liver of a child who underwent living donor liver transplantation for end-stage liver disease and severe hepatopulmonary syndrome. The manuscript describes the clinical, radiological and histopathological findings of this case and also highlights the dilemma associated with management of this case had the diagnosis been made in the preoperative setting and also about the proposed management plan for this case in the postoperative period.

BRAF V600E Mutant Lung Adenocarcinoma Presenting With a Skull Base Metastasis and Pituitary Adenoma Collision Tumour

We report an unusual initial presentation for metastatic lung adenocarcinoma (LAC) with progressive loss of vision, a rare molecular phenotype and rapid visual response to surgical resection. A 60-year-old female presented with rapid and progressive visual loss over four weeks. Contrast-enhanced CT and MRI scans showed an enhancing lobulated mass in the base of skull infiltrating into the sella turcica. The patient underwent transnasal endoscopic debulking of the mass with rapid improvement in her vision. Histology showed a collision tumour with a pituitary adenoma and a microacinar metastatic adenocarcinoma. Staging CT of the chest, abdomen and pelvis showed a T4 N2 M1 right LAC. Molecular profiling of the metastasis confirmed an activating mutation involving codon 600 of BRAF gene (BRAF V600E). The patient was treated with combination chemotherapy but rapidly deteriorated and unfortunately died due to progressive disease. Efforts to access BRAF/MEK inhibitors for off-label use were unsuccessful. We believe our patient would have benefited from a BRAF/MEK inhibitor. This case illustrates the very unusual presentation of metastatic LAC with visual loss secondary to a collision tumour containing a pituitary adenoma and metastatic adenocarcinoma.

Symbiotic collision tumour of the scalp: squamous cell carcinoma and malignant melanoma

Cutaneous collision tumours are the co-existence of two tumours of different histopathological morphologies that coincide at the same or adjacent anatomical sites. A large scalp nodule excised from a 70 year-old man revealed a collision tumour composed of cells of squamous carcinoma (SCC) and malignant melanoma. Immunohistochemistry using dual staining for melanoma and squamous cell carcinoma demonstrated an unusual pattern; nests of melanoma cells surrounded by a layer of squamous carcinoma cells. The unique architecture observed in the case suggested a relationship between the two tumours.

Apoplexy of a collision tumour composed of subependymoma and cavernous-like malformation in the lateral ventricle: a case report

Subependymomas are rare benign tumours arising from subependymal glial precursors that usually remain asymptomatic or may present due to obstruction of cerebrospinal fluid pathways. We describe the first report of intraventricular haemorrhage from subependymoma and cavernous-like malformation collision tumour in a 74-year-old male presented with an impaired level of consciousness.

Collision tumour of large-cell neuroendocrine carcinoma and adenocarcinoma in the stomach: A case report

Concurrence of adenocarcinoma and large-cell neuroendocrine carcinoma of the stomach is a rare condition. Here, we report a case of gastric collision tumour with large-cell neuroendocrine carcinoma and adenocarcinoma. A 71-year-old Peruvian man presented with nausea, epigastric pain, and weight loss for seven months. An Endoscopic evaluation revealed a huge ulcerative and infiltrative mass in the upper and middle third of the stomach. The patient underwent a D2 total gastrectomy. Microscopically, two separated and attached ulcerative lesions were recognised. The proximal to the cardial lesion showed neuroendocrine morphology and immunoreactivity for synaptophysin, and the other a moderated tubular adenocarcinoma Borrmann type III. Both lesions invaded serosa and lymph nodes metastases were found in 17 of 41 lymph nodes retrieved (one lymph node with neuroendocrine metastatic deposits).

A collision tumour consisting of malignant trichoblastoma and melanosarcoma in a rabbit

A 7-year-old mixed breed neutered female rabbit (Orytolagus cuniculus) developed a solitary black nodular mass (1 cm in diameter) in the skin of the right flank. Microscopically, the mass consisted of an admixture of neoplastic trichoblasts and melanocytes. The former were arranged as solid, trabecular, island-like and gland-like structures and the cells had oval nuclei with prominent nucleoli and lightly eosinophilic scant cytoplasm. The latter population exhibited prominent nuclear atypia and high mitotic index in the clusters of a few cells or single cells. Immunohistochemically, the neoplastic trichoblasts expressed cytokeratins and E-cadherin, while the neoplastic melanocytes expressed vimentin, S100 protein, melan-A and melanoma antigen. A diagnosis of collision tumour involving malignant trichoblastoma and melanosarcoma was made.

Esthesioneuroblastoma as a collision tumor

Esthesioneuroblastoma is an uncommon malignant neoplasm of nose and paranasal sinuses. Esthesioneuroblaslvma presenting as a collision tumour is very rare. The case of such a rare presentation is being reported here in a patient with previous history of squamous cell carcinoma uvula, post irridiatted; who now developed a bleeding nasal mass which proved to be a collision timour c ontaining both squamous cell carcinoma and Esthesioneuroblastoma on biopsy.

A tumour with a neuroendocrine and papillary serous component: two or a pair?

AIMS

To examine the clonal origin of a tumour, made up of a neuroendocrine component and a papillary serous component by comparing the pattern of loss of heterozygosity (LOH) and the immunohistochemical protein expression of both components.

METHODS/RESULTS

A 70 year old woman, known to have a metastasised neuroendocrine carcinoma, underwent resection of the distal part of the ileum because of obstruction by a mesenterial mass. The macroscopically homogeneous mesenterial mass consisted histologically of an admixture of a neuroendocrine component and a papillary serous carcinoma. Loss of heterozygosity (LOH) analysis of both components with a panel of 15 polymorphic microsatellite markers showed a distinctive pattern of LOH, and both components showed LOH on chromosome 4q and 17, but involving different alleles at the same locus. Moreover, both components showed different immunohistochemical staining patterns for neuroendocrine markers, cytokeratin 7, carcinoembryonic antigen, and CA125.

CONCLUSION

Both LOH analysis of the neuroendocrine and papillary serous components of this tumour and the immunohistochemical profile of both components are consistent with a different clonal origin. The tumour is probably a collision tumour, in which the papillary serous carcinoma must have been of peritoneal origin because necropsy revealed a normal uterus and normal ovaries.