scholarly journals Dermal Melanoma with Schwannoma-Like Differentiation in a Brown Bullhead Catfish (Ictalurus Nebulosus)

2002 ◽  
Vol 14 (3) ◽  
pp. 247-250 ◽  
Author(s):  
Kaori Sakamoto ◽  
M. Randall White

A dermal melanoma with histologic similarities to mammalian melanocytic schwannomas was diagnosed in a wild-caught brown bullhead catfish ( Ictalurus nebulosus). The diagnosis was based on cytologic, histopathologic, immunohistochemical, and ultrastructural findings. The neoplasm protruded from the cutaneous surface of the dorsal midline immediately caudal to the dorsal fin, was diffusely black and focally ulcerated, and was attached to the underlying skin by a broad-based stalk. Cytologically, the tumor was composed of a monomorphic population of melanophores, the melanin-producing and storing cells within the dermis and epidermis of fish that are partially responsible for rapid color changes. Histopathologic examination of the neoplasm revealed an unencapsulated, well-circumscribed, moderately cellular neoplasm composed of 2 distinct cell populations: spindle cells arranged in a “herringbone” pattern and numerous melanophores. The spindle cells had scant bipolar eosinophilic cytoplasm, with small centrally located vesicular nuclei; nucleoli were not seen. The histologic appearance was similar to that described for mammalian melanocytic schwannomas. Immunohistochemically, the spindle cells exhibited positive cytoplasmic staining for S-100 protein but were negative for vimentin, neurofilament protein, and glial fibrillary acidic protein. Ultrastructurally, the tumor consisted of neoplastic spindle cells with rudimentary cell junctions, actin bundles, and few melanosomes and melanophores with abundant intracytoplasmic melanosomes.

CytoJournal ◽  
2007 ◽  
Vol 4 ◽  
pp. 18 ◽  
Author(s):  
Becky L Van Ells ◽  
James E Madory ◽  
Rana S Hoda

Background Desmoplastic melanoma is a variant of malignant melanoma that can range in appearance from sarcomatoid to scar-like. Cytomorphology of desmoplastic melanoma has been previously described on conventional smears; however, to our knowledge, detailed cytomorphology on ThinPrep has so far not been described. Herein, we describe the cytomorphology of two cases of desmoplastic melanoma on fine needle aspiration processed as ThinPrep slides and compare it to that seen on conventional smears. Pertinent immunocytochemical stains, performed on ThinPrep slides are also discussed. Case presentation The first case is a woman with a history of desmoplastic melanoma of the scalp with previous local recurrences and lymph node metastasis with a new submandibular mass. The second case is a man with a previously resected desmoplastic melanoma with his first local recurrence. Conventional smears, including air-dried Diff-Quik-stained and alcohol-fixed Papanicolaou-stained smears, demonstrated aggregates of pleomorphic spindle cells admixed with fibrous stroma and single spindle cells. In both cases, nuclei were elongated and plump with irregular nuclear contours, deep grooves, and folds. Chromatin was dark and coarse with either inconspicuous or multiple prominent nucleoli. Cytoplasm was located at the nuclear poles and was fine, wispy, and delicate. The background was clean with no evidence of necrosis or melanin pigment. Papanicolaou-stained ThinPrep slides were prepared from needle rinses and demonstrated excellent correlation of nuclear and cytoplasmic detail of single spindle cells to that seen on conventional smears with the exception of only slight decrease in nuclear size; however, nuclear and cytoplasmic detail of spindle cells embedded in stroma was markedly attenuated. Confirmatory immunostain for S-100 protein in both cases was performed on ThinPrep slides demonstrating crisp cytoplasmic staining in the spindle cells. Conclusion The cytomorphology of desmoplastic melanoma shows excellent correlation between cytomorphology of single spindle cells on conventional smears and on ThinPrep slides. The major difference noted on ThinPrep slides was attenuated nuclear and cytoplasmic detail of spindle cells embedded in fibrous stoma.


1987 ◽  
Vol 73 (4) ◽  
pp. 425-429 ◽  
Author(s):  
Stefania Dante ◽  
Giuseppe Viale ◽  
Paolo Dalla Palma

A case of gangliocytic paraganglioma of the second portion of the duodenal loop is presented. The tumor was polypoid and, histologically, composed of mature ganglion cells, spindle cells and epithelial-like cells. Immunocytochemical examination demonstrated the presence of neurofilament 200 K and S-100 protein only in the first two types of cells; all the cells were positive for neuron-specific enolase. The reaction for cytokeratin was negative in all neoplastic components. According to morphologic and immunocytochemical findings, we suggest a hamartomatous nature of this entity.


2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii429-iii429
Author(s):  
Takeyoshi Tsutsui ◽  
Yoshiki Arakawa ◽  
Yasuhide Makino ◽  
Hiroharu Kataoka ◽  
Sachiko Minamiguti ◽  
...  

Abstract The most recurrent fusion of CNS high-grade neuroepithelial tumor with MN1alteration(HGNET-MN1) is MN1- BEN Domain Containing 2(BEND2) fusion. Recently, there was a report of a 3-month-old boy with spinal astroblastoma, classified as CNS HGNET-MN1 by DKFZ methylation classification but positive for EWSR1-BEND2 fusion(Yamasaki, 2019). Here, we report a 36-year old man with a spinal cord astroblastoma with EWSR1 alternation. The patient presented with back pain, gait disorder and dysesthesia in lower extremities and trunk was referred to our hospital. MRI showed intramedullary tumor in Th3-5 level, displaying low-intensity on T1 weighted image, high-intensity on T2 weighted image, and homogeneous gadolinium enhancement. Partial removal was performed with the laminectomy. The tumor extended to extramedullary and its boundary was unclear. Histological examinations showed the epithelium-like tumor cells with eosinophilic cytoplasm with high cellularity palisade, intracellar fibrosis, and mitosis. Immunohistochemical staining showed positive for Olig2, GFAP, EMA, SSTR2, S-100, but negative for p53, PgRAE1/AE3. The tumor was diagnosed as astroblastoma, and was classified as HGNET-MN1 by the DKFZ methylation classifier. However, the MN1 alternation was not detected by fluorescence in situ hybridization, instead EWSR1 and BEND2 alternations which suggested EWSR1-BEND2 fusion were detected. After radiation therapy of 54Gy/30fr with bevacizumab and temozolomide, the residual tumor reduced the size and his symptoms improved. This case provides evidence that EWSR1-BEND2 fusion is recurrent in HGNET-MN1 and, as previously reported, suggests the importance of BEND2 in this entity. These two cases suggested that it may be the BEND2 alteration that biologically defines the HGNET-MN1 subclass rather than MN1.


2000 ◽  
Vol 124 (1) ◽  
pp. 130-134
Author(s):  
P. M. Alli ◽  
B. J. Crain ◽  
R. Heitmiller ◽  
P. Argani

Abstract The identification of malignant melanoma in a visceral organ of nonepidermal origin is not an uncommon occurrence. Frequently, these cases are solitary metastases that present years after a thin epidermal melanoma has been diagnosed (and sometimes forgotten). However, primary visceral melanomas have been reported that have not been preceded by an epidermal lesion. We describe herein a unique case of melanoma presenting as a primary intrathymic tumor. The patient had no previous history of epidermal melanoma, and extensive workup did not reveal evidence for an alternative primary site. The tumor exhibited histologic features characteristic of melanoma, including an abundance of large pleomorphic cells with eosinophilic cytoplasm, prominent nucleoli, and occasional intranuclear inclusions. Tumor cells stained for HMB-45 and S-100 protein and ultrastructural analysis revealed stage II and stage III melanosomes. The patient remained free of disease until intrathoracic recurrence was detected on a computed tomographic scan 14 months later. The lack of clinical history and physical findings of melanoma at presentation, the intrathymic location of the tumor, and the pattern of recurrence suggest that this case likely represents a primary thymic melanoma, a previously unreported entity.


2015 ◽  
Vol 36 (6) ◽  
pp. 3801
Author(s):  
Clairton Marcolongo-Pereira ◽  
Bruna Da Rosa Curcio ◽  
Douglas Pacheco Oliveira ◽  
Ana Carolina Barreto Coelho ◽  
Bianca Lemos Santos ◽  
...  

A case of T small cell type lymphoma in the brain of a horse is described. A 20-year-old female Crioulo equine showed neurological signs characterized by ataxia, circling and partial loss of smell and sight. During necropsy, a whitish, firm, unencapsulated mass compressing the structures of the nervous tissue was observed, extending from the olfactory bulb to the internal capsule of the right telencephalon. Microscopic examination showed the proliferation of round cells with a small to moderate amount of eosinophilic cytoplasm. Nuclei were centrally located, irregularly round and occasionally cleaved and hyperchromatic. Immunohistochemistry for CD3 showed a moderate diffuse cytoplasmic staining. This is a rare primary central nervous system lymphoma in horses, with few reports in the veterinary literature. Nevertheless, it should be considered as a differential diagnosis in equines with neurological signs.


Author(s):  
Hamidreza Fattahian ◽  
Pejman Mortazavi ◽  
Hamidreza Moosavian ◽  
Hamid Mohyeddin ◽  
Roozbeh Moridpour

Accurate diagnostic approaches to differentiate peripheral nerve sheet tumours from others have not been firmly established. The aim of this case report was to diagnose neurofibroma using a combination of diagnostic imaging, histopathology and immunohistochemistry, which were applied to a canine neurofibroma arising in the left mandible. The tumour was surgically excised and examined histologically. Round or spindle cells, with elongated, dense and homogenous chromatin and pale cytoplasm typical of Schwann cells in an abundant fibromyxomatous stroma, with ruby collagen fibres were seen. Immunohistochemistry demonstrated that S-100 and vimentin were more than 70% positive. Neurofibroma may therefore be recognisable using markers such as S-100 and vimentin.


2009 ◽  
Vol 2009 ◽  
pp. 1-6 ◽  
Author(s):  
Kayo Kuyama ◽  
Sisilia Fusi Fifita ◽  
Masamichi Komiya ◽  
Yan Sun ◽  
Yoshiaki Akimoto ◽  
...  

The purpose of this study was to determine the clinicopathological and immunohistochemical features of lipoma/fibrolipoma with rare occasions as osseous and/or chondroid differentiation in the oral cavity. Two cases of the tumors, who presented with a painless, relatively hard mass on the oral mucosa, were studied. These were consisted of a well-circumscribed mass of fatty tissue with chondroid and significant fibrous component intermixed with the lobules of fat cells with chondroid and woven bone component, respectively. Immunohistochemical study revealed that peripheral spindle cells around chondroid tissue stained diffusely for S-100 & and Sox-9, though peripheral spindle cells around osteoid tissue only stained for RUNX-2. According to review of the literature, lipoma/fibrolipoma with osseous and/or chondroid differentiation was 18 cases. Also fibrolipoma with osseous and chondroid differentiation is the first to be reported here. These results indicated that the cartilage/bone is produced by differentiation of undifferentiated mesenchymal cells of stroma.


1980 ◽  
Vol 58 (10) ◽  
pp. 1899-1907 ◽  
Author(s):  
Lars-Ove Eriksson ◽  
Theo van Veen

Locomotor and feeding activity was investigated under(1) 12 h light(L): 12 h dark(D)and 16 h L: 8 h D, (2) 24 h D and 24 h L, and (3) dark pulses (0.75 h L: 0.25 h D), in the brown bullhead (Ictalurus nebulosus). In addition to locomotor and feeding activity, reaction time (latency time on lights-off and lights-on) was also measured.Fish subjected to a light–dark regime showed nocturnal behaviour, in many cases with a positive phase angle difference (i.e., the animals ceased their activity several hours before lights-on). Further, the actograms showed, as expected, a distinct 24 h rhythm. Only 2 brown bullheads out of 15, subjected to constant conditions, showed a circadian component in the locomotor activity, which could only be detected by frequency analysis.Nine out of 12 animals subjected to dark pulses (0.75 h L: 0.25 h D) showed a free-running circadian rhythm (approximately 23 h) in locomotor activity and 2 out of 3 showed such a rhythm in feeding activity. Observations and measurements of reaction time on leaving and re-entering the shelter after lights-off and lights-on (0.75 h L: 0.25 h D) showed also that this parameter has a circadian course. Measurements performed a fortnight later showed a similar, but less pronounced, pattern of behaviour.Dark pulses are thought to prevent rapid dissociation of a flexible multioscillatory circadian system in the brown bullhead.


1993 ◽  
Vol 71 (2) ◽  
pp. 437-440 ◽  
Author(s):  
R. J. Ongarato ◽  
E. J. Snucins

Models of potential brood predators placed near the nest were used to elicit defence behaviour in male smallmouth bass (Micropterus dolomieui) in the field. The three predator models represented a conspecific, a species found in the lake (yellow perch, Perca flavescens), and a species not present in the lake (brown bullhead, Ictalurus nebulosus). Aggressive behaviour increased with brood age and with decreasing distance between model and nest. Brood-guarding smallmouth bass exhibited a generalized response to the three predator models and did not discriminate between them by altering levels of aggression.


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