Intraoral lipoma with degenerative changes mimicking atypical lipomatous tumor: an immunohistochemical study.

Lipomas are mesenchymal neoplasms relatively uncommon in the oral cavity. Lipomas can exhibit histopathological features mimicking atypical lipomatous tumors (ALT) or dysplastic lipoma (DL) in the presence of degenerative changes. Relevantly, immunohistochemistry assists in the correct diagnosis. Herein, we present the case of a 54-year-old male with a sessile nodule located on the dorsum of the tongue. The histopathological analysis showed a diffuse, non-circumscribed adipocytic proliferation constituted by cells of variable size containing cytoplasmic vacuoles and displaced nuclei, some resembling lipoblasts supported by fibrous connective tissue stroma. By immunohistochemistry, tumor cells were positive for vimentin, S100, FASN, CD10, and p16. Rb expression was intact. Moreover, CD34, p53, MDM2, and CDK4 were negative. After 2-year of follow-up, no alteration or recurrence was observed. In conclusion, MDM2, CDK4, p53, and Rb immunomarkers can be used reliably to differentiate benign lipoma with degenerative changes from ALT and DL.

Intraoral lipoma with degenerative changes mimicking atypical lipomatous tumor: an immunohistochemical study

ABSTRACT Lipomas are mesenchymal neoplasms relatively uncommon in the oral cavity. Lipomas can exhibit histopathological features mimicking atypical lipomatous tumors (ALT) or dysplastic lipoma (DL) in the presence of degenerative changes. Relevantly, immunohistochemistry assists in the correct diagnosis. Herein, we present the case of a 54-year-old male with a sessile nodule located on the dorsum of the tongue. The histopathological analysis showed a diffuse, non-circumscribed adipocytic proliferation constituted by cells of variable size containing cytoplasmic vacuoles and displaced nuclei, some resembling lipoblasts supported by fibrous connective tissue stroma. By immunohistochemistry, tumor cells were positive for vimentin, S100, FASN, CD10, and p16. Rb expression was intact. Moreover, CD34, p53, MDM2, and CDK4 were negative. After 2-year of follow-up, no alteration or recurrence was observed. In conclusion, MDM2, CDK4, p53, and Rb immunomarkers can be used reliably to differentiate benign lipoma with degenerative changes from ALT and DL.

Primary cutaneous CD8+ cytotoxic T-cell lymphoma of the face with intraoral involvement, resulting in facial nerve palsy after chemotherapy.

The primary cutaneous (PC) CD8+ T-cell lymphoproliferative disorders (LPDs) comprise clinically and histopathologically heterogeneous entities including mycosis fungoides, lymphomatoid papulosis, hydroa-vacciniforme-like LPD, subcutaneous panniculitis-like T-cell lymphoma (TCL), PC acral CD8+ TCL, PC CD8+ aggressive epidermotropic cytotoxic TCL, and PC peripheral TCL, not otherwise specified (PTCL-NOS). We describe a 33-year-old man who presented with progressive facial swelling and lower lip involvement 1 year ago. Microscopy revealed an atypical small to medium-sized lymphoid proliferation exhibiting perivascular accentuation, adnexotropism, and apoptotic cell debris, without surface epithelium involvement. The tumor cells were positive for CD3, CD8, granzyme B, perforin, MUM1/IRF4, and TCR-BF1. The Ki-67 labeling index was 48%. EBER1/2 was negative. Additional studies confirmed localized disease. The diagnosis favored PC-PTCL-NOS. Two months after completing chemotherapy, right-sided facial nerve palsy was diagnosed. CD8+ T-cell LPDs should be considered in the differential diagnosis when assessing facial swelling with intraoral involvement.

Chondromyxoid fibroma affecting the maxilla in a 1-year-old child: Immunohistochemical analysis and literature review.

Chondromyxoid fibroma (CMF) is a benign chondroid/myxoid matrix-producing tumor that often develops in the long bones of young adults. CMF is rarely reported in the craniofacial skeleton, with most cases presenting with bone erosion or destruction, which may lead to a misdiagnosis. To date, approximately 129 cases of CMF in the craniofacial region have been reported, with only three cases in patients aged less than 1 year. Of these 129 cases, only 34 affected the jaws. A 1-year-old boy presented with a mass in the left anterior maxilla, extending and compressing the ipsilateral nasal cavity. After surgical excision of the lesion, microscopy revealed spindle-to-stellate tumor cells surrounded by a predominant myxoid stroma containing focal slit-like vascular channels and hemorrhagic areas. Immunohistochemistry showed positivity for vimentin, CD10, and α-SMA (focal). The Ki-67 labeling index was 6%. CFM should be included in the differential diagnosis when assessing maxillary tumors in pediatric patients.

Concomitant endogenous and exogenous etiology for gingival pigmentation.

Oral pigmented lesions can be physiological or pathological, exogenous or endogenous, as well as focal, multifocal, or diffuse. Among them, the oral melanotic macule (OMM) is a small, well-delimited brown-to-black macule, often affecting the lip and gingiva. Amalgam tattoo (AT) is a grey or black area of discoloration on the oral mucosa as a result of entry of dental amalgam into the soft tissues, commonly gingiva and alveolar ridge. Herein, we present a patient with gingival pigmentation with features of both OMM and AT in the same location.