Bavi Prashant, Shet Tanuja, Gujral Sumeet
Department of Pathology, Tata Memorial Hospital, Parel, Mumbai, Maharashtra, India.
Acta Cytol. 2005 Jul-Aug;49(4):424-6. doi: 10.1159/000326177.
Malignant melanomas in the medastinum are extremely rare. Both primary melanomas and metastatic lesions from a primary elsewhere can occur in the mediastinum. Aspiration biopsy of a melanoma at this unusual site may pose problems in diagnosis.
A 35-year-old woman presented with an anterior mediastinal mass. Cytologic smears were hemorrhaghic and revealed a loosely dispersed population of spindle cells with prominent nucleoli. In view of the location, the possibility of spindle cell thymoma was suggested on cytology. Subsequent histology revealed a malignant melanoma.
This case stresses that the cytopathologist should keep in mind the remote differential diagnosis of a malignant melanoma while evaluating spindle cell neoplasms of the mediastinum, especially in tumors with prominent cell dispersal and with cells that have prominent nucleoli even without melanin pigment. Accurate diagnosis helps in evaluating patients and avoids unnecessary surgery when the lesion represents a metastasis to the mediastinum from a primary elsewhere.
纵隔恶性黑色素瘤极为罕见。原发性黑色素瘤以及源自其他部位原发性肿瘤的转移性病变均可发生于纵隔。在此不寻常部位对黑色素瘤进行穿刺活检可能在诊断方面存在问题。
一名35岁女性因前纵隔肿物就诊。细胞学涂片有出血，显示为一群松散分布的梭形细胞，核仁明显。鉴于肿物位置，细胞学检查提示梭形细胞胸腺瘤的可能性。随后的组织学检查显示为恶性黑色素瘤。
该病例强调，细胞病理学家在评估纵隔梭形细胞瘤时，应牢记恶性黑色素瘤的鉴别诊断，尤其是对于细胞分散明显且细胞即使无黑色素沉着但核仁明显的肿瘤。准确诊断有助于评估患者，并在病变为源自其他部位原发性肿瘤的纵隔转移时避免不必要的手术。
