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Retinoblastoma
Published in Dongyou Liu, Handbook of Tumor Syndromes, 2020
Claire Hartnett, Mandeep S. Sagoo, M. Ashwin Reddy
Histologically, retinoblastomas are poorly differentiated malignant neuroblastic tumors, composed of cells with large hyperchromatic nuclei and scanty cytoplasm (Figure 7.2). Mitotic figures are common. In some tumors, differentiated cells form typical Flexner−Wintersteiner rosettes. Homer−Wright rosettes can also occur. Retinoblastomas often outgrow their blood supply, leading to cell necrosis. Apoptosis can also be evident in retinoblastomas. Calcification is also a common finding in retinoblastoma, but its etiology is not known.
Head and Neck Pathology
Published in John C Watkinson, Raymond W Clarke, Terry M Jones, Vinidh Paleri, Nicholas White, Tim Woolford, Head & Neck Surgery Plastic Surgery, 2018
Ram Moorthy, Adrian T. Warfield, Max Robinson
The malignant cells are uniform, with small round nuclei, scant cytoplasm and possess finely stippled (salt and pepper) chromatin. Hyams’ classification system divides olfactory neuroblastoma into four types (Table 26.10).14 The better-differentiated (grade I and II) examples are sometimes termed ‘aesthesioneuroblastoma’. Homer–Wright pseudorosettes are formed by cells mantling solid, fibrillary neuropil stroma (Figure 26.18). Flexner–Wintersteiner rosettes consist of cells surrounding an empty pseudolumen. Other tumours may form perivascular rosettes encircling blood vessel lumina. IHC may aid discrimination between this and other primitive neoplasms (so-called round blue cell tumours), such as lymphoma, Ewing’s tumour, melanoma, Merkel cell tumour, rhabdomyosarcoma, nephroblastoma, retinoblastoma and primitive neuroectodermal tumour (PNET).47 There is, however, no single specific positive marker.
Neuropathology Of Neuro-Ophthalmic Disorders
Published in Vivek Lal, A Clinical Approach to Neuro-Ophthalmic Disorders, 2023
The retinoblastoma arises from either the inner or outer nuclear layer of retina. It may show an endophytic or exophytic or both. The endophytic growth fills the vitreous chamber and exophytic tumor grows outwardly and lifts the retina (Figure 25.16a and b). The tumor looks pale necrotic mass with area of necrosis and calcification. Histological diagnosis is generally straightforward. The histology is that of a blue round cell tumor disposed in a diffuse sheet of cells (Figure 25.16c). The tumor cells contain small amount of cytoplasm and a large hyperchromatic nucleus. The cells may be polygonal in shape and exhibit variable degree of anaplasia mimicking morphology of large cell medulloblastoma. Perivascular arrangement of cells surrounding a necrotic area may be found. Cellular differentiation may either be in the form of Flexner-Wintersteiner rosettes which are composed of an “empty” lumen surrounded by columnar cells or the Homer Wright rosettes consisting of cells surrounding a central lumen made up of their processes (Figure 25.16d).34 The dual presence of Homer Wright and Flexner-Wintersteiner rosettes is pathognomonic for retinoblastoma. Cellular differentiation is not necessarily associated with prognosis, and therefore, it is not an important histologic parameter for evaluation. Rather the degree of anaplasia is known to be associated with outcome of the patients. Poorly differentiated tumor shows brisk mitoses. Microscopic areas of necrosis and calcification are frequently observed. Tumors with germline mutation may show multifocal tumors arising from retina. Currently, most tumors are treated with chemotherapy, and if eye is enucleated due to any indication, it may be difficult to find any residual tumor in pathology specimens. In such situations, many ophthalmologists cross-check with the reporting pathologist about the presence or the absence of tumor in specific suspected locations. Further radiotherapy treatment will depend on pathologist's report. Invasion into choroid could be focal (less than 3mm in any diameter) or massive (more than 3mm in any diameter– thickness or width).33 Some tumors may invade sclera and extend into the extraocular space. Such cases have bad prognosis. Retinoblastoma may spread along the optic nerve or through subarachnoid space to involve intracranial compartment. Optic nerve invasion should be graded as pre-laminar, post-laminar or extending up to resected margin. Massive choroid invasion, retrolaminar invasion, involvement of anterior chamber, iris, sclera and extra scleral compartment are all associated with greater chance of recurrence and metastasis. Such tumors require adjuvant radiotherapy.33 Sudden tumor regressions are known to occur.
Orbital invasion by Esthesioneuroblastoma: a comparative case series and review of literature
Published in Orbit, 2022
Kevin Wu, Sarah A. Avila, Rupak Bhuyan, Ammar Matloob, Anthony G. Del Signore, Constantinos Hadjipanayis, James Chelnis
Histological diagnosis is important to rule out ENB versus other sinonasal malignancies, as ENB survival and control rates are much higher compared to non-ENB diagnoses.7 Typical histology shows a lobular architecture with fibrovascular septae, small round-to-oval blue cells, prominent nuclear membranes, and scant cytoplasm.6,8 Homer Wright and Flexner-Wintersteiner rosettes may be present, indicating neuroectodermal origin. Immunohistochemistry stains are also necessary for diagnosis. Synaptophysin, chromogranin A, S-100, CD56, neuron-specific enolase, and glial fibrillary acidic protein are positive while stains for epithelial, muscle, and lymphoid antigens are generally negative including CK5/6, CK7, CD99, and myogenin.9 These stains can be weakly positive, making the diagnosis between ENB, sinonasal undifferentiated carcinoma, sinonasal neuroendocrine carcinoma, lymphoma, and melanoma challenging.7,8 Thus, it is necessary to correlate anatomic site, imaging findings, histologic features, and clinical features to establish the correct diagnosis.
Molecular analysis confirms retinoblastoma diagnosis in a histologically undifferentiated retinal tumor in an adult
Published in Ophthalmic Genetics, 2020
Sameh E. Soliman, Silvia Martínez, M. Laura De Nicola, Rasmus Kiehl, Hatem Krema
At this point, active retinoblastoma was considered. The eye was classified as group E (International Intraocular Retinoblastoma Classification)(11). Enucleation was undertaken. Tumor histopathology (Figure 2) showed poorly differentiated cells with brisk mitotic activity and apoptotic bodies, with large necrotic areas and absence of Flexner-Wintersteiner rosettes and fleurettes. No malignant cells involved the optic nerve, choroid, or sclera. The immunohistochemistry demonstrated a variable Mib-1/ki-67 proliferation index (40–70%), with synaptophysin positivity (neural tissue marker), S100 negativity (melanoma marker), and CD20 negativity (lymphocytic marker). These findings were still inconclusive for a retinoblastoma diagnosis despite additional leveled sections. Level of histological anaplasia (12) did not conform to the observed slow tumor growth over 3 years.
Esthesioneuroblastoma presenting with orbital signs and ectopic adrenocorticotropic hormone syndrome
Published in Baylor University Medical Center Proceedings, 2022
Wesley M. Gillette, Donald Carroll Hubbard, Jana Nicole Waters, Adam Stephen Johnson
The differential diagnosis for esthesioneuroblastoma includes a wide variety of orbital and sinonasal tumors including cavernous hemangioma, squamous cell carcinoma, sinonasal undifferentiated carcinoma, and inverting papilloma, among others. Diagnosis can prove difficult, as the presenting symptoms are often nonspecific and may mimic more common sinonasal conditions such as rhinosinusitis and nasal polyposis. As a result, there can be an extensive delay between symptom onset and diagnosis.8 Crucial elements of patient evaluation include tissue biopsy (often possible with nasal endoscopy) and imaging with CT and MRI. Histologic exam of this tumor shows lobules of small, round blue cells occasionally forming Homer-Wright or Flexner-Wintersteiner rosettes.9