PMC4247173_01
Clinical manifestations of melanotic neuroectodermal tumor of infancy originating in the mandible.
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There was no tenderness of the tumor mass, and it lay firm on the gum (Fig. 1).
(A) Transverse and (B) coronal section computed tomography images of manibular melanotic neuroectodermal tumor of infancy of the right mandible.
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Computed tomography (CT) examination (Fig. 2) revealed low-density lesions of the right mandible, with unclear boundaries.
Magnetic resonance images of mandibular melanotic neuroectodermal tumour of infancy. (A) T1-weighted and (B) T2-weighted images.
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T1-weighted imaging (T1WI) revealed a heterogeneous, but generally low-intensity, quasi-circular tumor (Fig. 3A). T2WI identified an uneven, higher-intensity tumor, but no invasion into the mouth floor or the vestibular sulcus mucosa (Fig. 3B).
Surgical procedure and findings. (A) Tumor in the mental foramen with intact envelope. (B) Tumor exhibiting growth into the surrounding cancellous bone with visible black flecks in the sclerotin. (C) Tumor section with gray and black boundaries. (D) The remaining mandible cavity post-tumor resection.
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A solid black tumor in the mental foramen, with intact envelope (Fig. 4A), exhibited infiltrative growth into the surrounding cancellous bone (Figs. 4B and 6), and contained the dental germ of tooth 81 and 82. The remaining cavity of the mandible exhibited a honeycomb structure, and invasive black flecks were observed in the sclerotin (Fig. 4B). Following tumor resection (Fig. 4D), the tumor envelop was found to be intact, with black and white stripes visible on the side of the section. The side of the section side was gray and black, with clear boundaries visible (Fig. 4C). The mandibular tissue was disrupted by the tumor (Fig. 4C).
Cancer cell types of melanotic neuroectodermal tumor of infancy in the fibrous connective tissue. (A) Larger pigmented cells (magnification, 40) and (B) nested small round cells (magnification, x400) (stain, hematoxylin and eosin).
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Microscopic examination revealed nested, small round cells and larger pigmented cells in the fibrous connective tissue, without evident pathological nuclear fission, necrosis or perineural invasion (Fig. 5).
Tumor cell invasion into the surrounding sclerotin. (A) Tumor cells separate from the bone trabecula (magnification, x400). (B) Tumor cell invasion of the bone trabecula (magnification, x40) (stain, hematoxylin and eosin).
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Certain tumor cells within the sclerotin were pigmented, but without a noticeable allotype (Fig. 6).
Inferior alveolar neural tube invasion by the tumor cells in the (A) soft tissue and (B) sclerotin (stain, hematoxylin and eosin; magnification, x40).
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Computed tomography images acquired to observe mandible development (A) immediately after surgery, (B) four months after surgery, and (C) one year after surgery.
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In order to detect any recurrence of the MNTI and observe the development of the mandible, CT images were acquired immediately after surgery, and at four months and one year post-surgery (Fig. 8).