Two synchronous lung metastases from malignant melanoma: the same patient but different morphological patterns

Abstract

Malignant melanoma is an aggressive cancer with a high metastatic potential. Among the multiple sites of metastatic disease, the lung is one of the most frequently involved sites. Typically, pulmonary metastases from malignant melanoma occur as solid nodules. Rarely, pulmonary involvement in metastatic melanoma occurs as subsolid nodules. The present article describes an unusual case of a patient with malignant melanoma that developed two synchronous pulmonary metastases with two different densities on CT images (one solid and the other subsolid) and different morphological patterns on histologic images. The radiologic-pathologic correlation of these two patterns of presentation was also reported.

Keywords: Histology; Malignant melanoma; Nonsolid nodule; Pulmonary metastases; Solid nodule; Subsolid nodule.

Fig. 1

Posteroanterior chest X-ray (left) and magnifications of the upper (white box) and lower (purple box) lobes of the right lung show the two pulmonary opacities (white and purple arrows). Note that the opacity of the upper lobe (white arrow and white box) is fainter than that of the lower lobe (purple arrow and purple box) (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article).

Fig. 2

Axial CT image with lung window setting (A) displays the nonsolid nodule in the right upper lobe (arrow). There is no evidence of the pulmonary nodule on axial CT image with mediastinal window setting (B).

Fig. 3

Axial CT image with lung window setting (A) displays the solid nodule in the right lower lobe (arrow). Precontrast (B), late arterial phase (C), and portal venous phase (D) images of the upper abdomen show the contrast-enhancement of the pulmonary nodule (curved arrows).

Fig. 4

Cropped axial CT images with the lung window setting showing the nonsolid (A) and solid (D) pulmonary nodules. (B, C) Histological hematoxylin and eosin (H-E) images of the nonsolid pulmonary nodule at the actual size (B) and at 10x (C) showing the neoplastic cell growth along the alveolar septa with the partial effacement of the alveolar architecture, which reflected the nonsolid appearance of this nodule on CT images. Note that some alveolar spaces are still recognizable. (E, F) Histological H-E images of the solid pulmonary nodule at the actual size (E) and at 20x (F) display the complete effacement of the alveolar architecture, which reflected the solid appearance of this nodule on CT images. Both pulmonary nodules were made by epithelioid malignant cells that were consistent with melanoma cells (C, F).