Malignant melanoma presenting as an intrathymic tumor - A primary thymic melanoma?

Citation
Pm. Alli et al., Malignant melanoma presenting as an intrathymic tumor - A primary thymic melanoma?, ARCH PATH L, 124(1), 2000, pp. 130-134
Citations number
17
Categorie Soggetti
Research/Laboratory Medicine & Medical Tecnology","Medical Research Diagnosis & Treatment
Journal title
ARCHIVES OF PATHOLOGY & LABORATORY MEDICINE
ISSN journal
00039985 → ACNP
Volume
124
Issue
1
Year of publication
2000
Pages
130 - 134
Database
ISI
SICI code
0003-9985(200001)124:1<130:MMPAAI>2.0.ZU;2-S
Abstract
The identification of malignant melanoma a visceral organ of nonepidermal o rigin is not an uncommon occurence. Frequently, these cases are solitary me tastases that present years after a thin epidermal melanoma has been diagno sed (and sometimes forgotten). However, primary visceral melanomas have bee n 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 w orkup did not reveal evidence for an alternative primary site. The tumor ex hibited histologic features characteristic of melanoma including an abundan ce of large pleomorphic cells with eosinophilic cytoplasm, prominent nucleo li, and occasional intranuclear inclusions. Tumor cells stained for HMB-45 and S100 protein and ultrastructure analysis revealed stage II and stage II I melanosomes. The patient remained free of disease until intrathoracic rec urrence was detected on a computed tomographic scan 14 months later. The la ck of clinical history and physical findings of melanoma at presentation, t he intrathymic location of the tumor, and the pattern of recurrence suggest that this case likely represents primary thymic melanoma, a previously unr eported entity.