• Obstetrics & gynecology science
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• v.61 no.6
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• pp.698-701
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• 2018

We report a rare case of vaginal amelanotic melanoma. Malignant melanomas are cutaneous and extracutaneous tumors that arise from embryological remnants of neural crest cells/melanocytes. Amelanotic melanomas at such rare locations can be misdiagnosed both clinically and radiologically. Therefore, histopathological examination and immunohistochemistry are mandatory for the diagnosis of these tumors. We diagnosed this case using histopathology and confirmed the diagnosis based on the presence of immunohistochemical markers human melanoma black 45 (HMB45) and S-100.

• Archives of Plastic Surgery
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• v.35 no.3
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• pp.312-315
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• 2008

Purpose: Amelanotic melanoma represents a melanoma with an absence or a small number of melanin pigments and comprises 2% of all melanomas. These melanomas are frequently misdiagnosed, probably because of its nonspecific clinical features and difficulty in diagnosis, resulting in delayed diagnosis and treatment. We report a patient with amelanotic melanoma, who underwent surgical treatment with sentinel lymph node biopsy using gamma probe. Methods: A 32-year-old female was presented with a slowly growing ill-defined, hypopigmented nonerythematous lesion with nail defect on right index finger tip. Preoperative punch biopsy was performed, showing an amelanotic melanoma. Sentinel lymph node biopsy was done using gamma probe(Crystal probe system, CRYSTAL PHOTONICS GmbH, Germany) and confirmed no evidence of regional lymph node metastases. The patient underwent amputation at the proximal interphalangeal joint. Results: Histopathologic findings showed superficial spreading melanoma. There were no melanin pigments in Hematoxylin & Eosin stain but positive immunohistochemical stainings for S-100 protein and Hmb45, which were consistent with amelanotic melanoma. Patient's postoperative course was uneventful without any complication and had no evidence of recurrence of tumor in 6 months follow-up period. Conclusion: Amelanotic melanoma is extremely rare subtype of malignant melanoma with histopathologic findings of atypical melanocytes without melanin pigments. Early detection is crucial since survival is strongly related to tumor thickness and tissue invasion at the time of diagnosis. Wide excision is the treatment of choice and other conjunctive therapy has not been successful.

• Archives of Craniofacial Surgery
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• v.21 no.2
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• pp.132-136
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• 2020

Oral mucosal melanoma is a very rare type of malignant melanoma, the characteristics of which differ from those of cutaneous melanoma. Primary amelanotic melanoma of the mandibular gingiva, which can invade the mandibular bone, is very rare worldwide. Here, we report a case in which we performed a reconstruction of the mandible and gingiva using the fibula osteocutaneous free flap procedure to treat a patient diagnosed with a primary amelanotic melanoma of the mandibular gingiva. The procedure was successful, and no recurrence was observed 10 months after surgery. Oral mucosal melanoma has a much poorer prognosis and a lower 5-year survival rate than cutaneous melanoma. However, recently, immunomodulatory therapies for mutations in melanocytic lesions have been used effectively to treat the increasing number of patients developing this type of melanoma, thus improving the prognosis of patients with oral mucosal melanoma.

• The Korean Journal of Cytopathology
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• v.4 no.1
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• pp.41-44
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• 1993

A case of primary amelanotic melanoma of the vagina diagnosed in scraping smear is described. A 64-year-old woman complained of vaginal bleeding with a $2.5\times2cm$ sized, fungating mass on the right lateral vaginal wall near the introitus for 2 months. Scraping smears from the mass showed scattered individual tumor cells with single, bi- or multi-nucleated eccentric nuclei having prominent macrouucleoli and occasional intranuclear inclusions. The cytoplasm was plump and cyanophilic with a indistinct rim. No melanin pigment was identified. Characteristic cytologic features of this case were very helpful to exclude more common squamous cell carcinoma in the vagina, which was strongly suggested in biopsy specimen.

• Korean Journal of Veterinary Research
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• v.35 no.2
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• pp.375-381
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• 1995

Two intraocular tumors were identified in low and medium dosed groups of a carcinogenicity study using 200 males and 200 females Sprague-Dawley rats in Screening & Toxicology Research Center, Korea Research Institute of Chemical Technology. The tumors were grossly observed as white or yellow, unilateral nodules. They were approximately $1-2{\times}3-5mm$ in size. The tumors located in the region of iris and/or ciliary body invaded peripheral cornea. The microscopic features were usually composed of spindle cells arranged in parallel, forming gently curving bundles or whorls. The spindle cells had poorly defined cell boundaries, scant to moderate cytoplasm, fusiform nuclei and indistinct nucleoli. Mitotic figures were rare and areas of necrosis were present. The spindle cells had positive immunoreactivity for S-100 protein and vimentin but negative for desmin, collagen and HMB-45 antibody. In special histochemical studies, the spindle cells react with Gomori's stain for argyrophih fibers, Prussian blue stain for iron but negative with Masson-Fontana's stain for melanin granules. Ultrastructurally, cytoplasmic premelanosomes were not observed in the tumor cells due to the poor preservation of tumor masses. Based on the results, the tumors were diagnosed as amelanotic melanoma.

• Journal of Veterinary Clinics
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• v.26 no.6
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• pp.612-615
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• 2009

A 10-year-old intact male mixed breed dog was presented with a three-month history of massive oral mass. Physical examination revealed extending mass from the right upper gingiva. No metastasis was found at the time of presentation. Histopathologic examination of biopsied tissue from the oral mass was consistent with a neuroendocrine tumor with generalized epithelioid cells and few spindle cells. There were highly mitoses and no visible melanin granules with H&E staining. Immunohistochemical staining for Melan A was performed on section of tumor and was strongly positive. Diagnosis was made as amelanotic malignant melanoma based on histopathology with Melan A immunohistochemistry. This case study indicates that the Melan A immunohistochemical staining may be valuable to diagnose amelanotic malignant melanoma in dogs.

• 대한세포병리학회:학술대회논문집
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• 1992.06a
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• pp.7.2-8
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• 1992

• The Korean Journal of Cytopathology
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• v.9 no.1
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• pp.111-115
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• 1998

Although the characteristic cytologic features of melanoma have been well described the diagnosis of metastatic melanoma by fine needle aspiration cytology (FNAC) may be difficult in the case of amelanotic melanoma and in the absence of awareness of clinical history. Furthermore, when the breast is the site of initial presentation, it could simulate a primary breast carcinoma leading to misdiagnosis. The recognition of metastatic malignant melanoma in FNAC material is essential to avoid an unnecessary mastectomy and to ensure appropriate chemotherapy. We experienced a case of metastatic melanoma of breast which presented as solitary breast mass in a 56-year-old woman. She had a history of surgical excision of right foot for melanoma one year ago. The cytologic smears were composed of noncohesive epithelioid cells with round or eccentric nuclei, bi-or multi-nucleation, prominent nucleoli, fine chromatin, and intranuclear inclusions. The cytoplasm of tumor cells had scanty melanin pigment but were diffusely positive for S-100 protein.

• Journal of Yeungnam Medical Science
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• v.5 no.1
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• pp.135-139
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• 1988

The primary malignat melanoma of the nasal cavity and paranasal sinuses is extemely rare and accounts for only between 0.6 and 2.5% of the total 'number of malignat melanoma at all sites. In the nose, the left side is involved in 60% of cases and the most frequent site is the septum followed by the inferior and middle turbinates. In the sinuses, the maxillary sinus is the site of origin in 80% of cases, followed by ethmoid sinus. The tumors are sessile or polypoid, with variable color such as pink. white, brown or black. Of all tumors, 10~30% are amelanotic, requiring special stains for melanin. When primary site of melanoma is mucosal origin. treatment of primary lesion is often hampered by anatomic retrictions and large size, which results from the delayed diagnosis caused by their location. We report 4 cases of primary malignant melanoma of nasal cavity with review of literature.

• Journal of Veterinary Clinics
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• v.31 no.5
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• pp.425-429
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• 2014

Two dogs were presented with a history of anorexia, respiratory distress, or epistaxis. On physical examination, the dogs showed difficulty breathing and open-mouth breathing and large masses were found on the hard palate and soft palate. Cardiac arrest happened in case 2 and the dog was stabilized with cardiopulmonary resuscitation and oxygen therapy. Computed tomography demonstrated that the mass occupied the oropharynx, intrapharyngeal ostium, and laryngopharynx including the hard palate and soft palate in case 1. Palliative surgery was decided to improve swallowing and breathing with owner's consent in two dogs. Buccal mucosal flaps were performed for reconstruction of defects using rotational and single-pedicle advancement flaps and bilateral 90 degree transposition flaps in cases 1 and 2, respectively. Histopathology results described the oral masses as amelanotic melanoma in two dogs. The owners reported that there was normal swallowing and breathing at 7 days postoperatively in two dogs. In case 1, recurrent tumor was identified caudal to the hard palate 4 weeks after surgery. The owner did not allow further treatment and the dog became lost to follow-up at 2 months postoperatively. In case 2, there was no clinical or radiographic evidence of a local recurrence or distant metastasis at 3 weeks after surgery. The owner informed that the dog died suddenly with no signs of anything particularly wrong at 7 weeks after surgery.