Hybrid salivary gland tumor of the upper lip or just an adenoid cystic carcinoma? Case report

Abstract

A 65 year-old male patient with a one year-duration tumoral growth located in the upper lip was diagnosed on incisional biopsy as epithelial-myoepithelial carcinoma. After wide surgical excision the histopathological analysis revealed the lesion was composed predominantly (>90%) of adenoid cystic carcinoma. In new sections it was found a very small and isolated area of adenoid cystic carcinoma at the bottom of the incisional biopsy. As surgical margins were free of lesion, no adjuvant treatment was given. The occurrence of a transitory ischaemic attack at 36 months of follow-up led to a neurological and MRI evaluation, which disclosed a well-defined 3.5x3 cm lesion suggestive of metastasis, located on the right temporal area. The lesion was surgically removed and a histopathological diagnosis of neurocysticercosis was rendered. After 40 months of follow-up there is no evidence of recurrence. Conclusion: True hybrid tumors of salivary glands are rare and treatment in each case should be done according to the component with the higher aggressiveness. However, the occurrence of epithelial-myoepithelial carcinoma areas within an adenoid cystic carcinoma seems to be a frequent finding, and because both lesions share a common origin, some authors consider that this may not be a true hybrid neoplasm but a variant of the latter.

Hybrid Carcinoma of the Larynx: A Case Report (Adenoid Cystic and Adenocarcinoma) and Review of the Literature

“…Fewer than 30 cases of hybrid tumors have been described since now, with most of them occurring in parotid and the minor salivary glands of palate. Patients with hybrid carcinoma in submandibular gland, upper lip, antrum, lacrimal gland, and larynx have also been reported [7, 18, 19]. …”

“…Most authors support that the biological behavior and the prognosis of a hybrid tumor are determined by the most aggressive of the coexisted carcinomas. For the same reason, the treatment is based on the therapeutic strategy for the most malignant of the coexisted tumors [18, 19]. …”

Dedifferentiated Salivary Hybrid Carcinoma of the Maxillary Sinus with Pagetoid Spread to the Overlying Lining Mucosa

“…Hybrid carcinoma of salivary glands is a very rare subtype of malignant salivary gland neoplasm with a little more than 30 cases documented in the literature [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] (See Table 1). Most cases of hybrid carcinoma of salivary glands have been reported in the parotid gland and palate.…”

Hybrid Carcinoma of The Parotid Gland: A Report of Three Extremely Rare Cases with An Immunohistochemical Analysis and A Review of The Literature

“…More than 30 cases of HC have been reported in the English literature (Table 1) [1,[3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. However, only 2 cases involving a combination of SDC and squamous cell carcinoma (SqCC) [3] and 3 cases involving a combination of salivary duct carcinoma (SDC) and epithelial-myoepithelial carcinoma (EMC) have been reported [5,16,23].…”