Oral malignant melanoma: A case report of an unusual clinical and histologic presentation
A 60-year-old female patient reported with the complaint of a growth on the palate and inability to wear the denture since 3 months. On clinical examination, the lesional mass was seen involving the entire hard palate as a pedunculated mass, measuring approximately 3 cm × 3 cm, attached to the palatal mucosa with a narrow stalk. The base of the pedunculated mass, the palatal mucosa and the surrounding alveolar mucosa showed areas of brownish black pigmentation. The mucosa on the oral side of the lesion showed a pale whitish color []. On palpation the lesion was smooth, non-tender, well defined, firm to hard in consistency with induration of the posterior margins.\nOn computed tomography an enhancing, infiltrative soft tissue mass arising from the hard palate with subtle bony erosion noted over the mid portion of the hard palate [] and bilateral submandibular lymphadenopathy were evident.\nA provisional diagnosis of malignant melanoma was considered and an incisional biopsy was performed which confirmed the diagnosis. The patient underwent total maxillectomy with neck dissection.\nThe histopathological examination of the excised tissue revealed cells with a clear cytoplasm and hyper chromatic nuclei resembling atypical melanocytes seen proliferating from dermal-epidermal junction into the connective tissue. The atypical melanocytes were epitheloid in the superficial region [], and spindle shaped in the deeper regions of the connective tissue. The spindle cell type predominated showing an irregular branching pattern with intervening fibrous septae [], these cells appeared fusiform to round in different orientations []. Atypical features like mitosis, multi-nucleation, pleomorphism, hyper chromatism, increased nuclear cytoplasmic ratio and prominent nucleoli were seen []. Pigmented nests of atypical melanocytes along with melanophages were seen in the superficial region. The tumor-stroma interface showed a marked inflammatory response and dense fibrosis. The evaluation the harvested submandibular lymph node showed metastatic involvement. The histopathology confirmed the diagnosis of malignant melanoma with metastatic level I nodes. The spindle cell predominance with collagenous stroma was suggestive of desmoplastic malignant melanoma.\nThe patient underwent reconstruction, prosthetic rehabilitation, and has been on regular follow with no recurrence till date.