M. Islam

Myopericytoma: report of two cases associated with trauma

Myopericytoma is a rare, recently described tumor demonstrating a hemangiopericytoma‐like vascular pattern. We present two cases of myopericytoma associated with trauma: a 64‐year‐old man who developed several nodules on his nose four months after sustaining multiple abrasions to his forehead and nose, and a 72‐year‐old woman with a solitary growth in the alveolar ridge of unknown duration. Biopsy specimens of the lesions in both cases demonstrated a striking concentric perivascular proliferation of bland spindle‐shaped pericytic cells characteristic of myopericytoma. Despite sharing morphologic features with angioleiomyoma, myofibroma and glomus tumor, myopericytoma is thought to represent a distinct perivascular myoid neoplasm of skin and soft tissues. The tumor is characterized by a radial and perivascular arrangement of ovoid, spindled to round neoplastic cells that are immunoreactive to alpha‐smooth muscle actin, often for h‐caldesmon as well as smooth muscle myosin‐heavy chain, and usually negative for desmin antibodies. Most cases of myopericytoma are benign, however, local recurrence and malignancy have recently been reported, Myopericytoma can be multifocal involving a single or multiple anatomic regions, and tends to occur in dermal and superficial soft tissues of adults primarily on the extremities. Our cases are unusual examples of myopericytoma manifesting as multiple nodules on the nose, and a solitary growth on the buccal mucosa after trauma.

Intraoral basal cell carcinoma, a rare neoplasm: report of three new cases with literature review.

Intraoral basal cell carcinoma (IOBCC) is an extremely rare entity that bears close microscopic resemblance to and is often confused with the peripheral ameloblastoma (PA). Basal cell carcinomas are thought to arise from pluripotential basal cells present within surface epithelium and adnexal structures, so theoretically they can arise within the oral cavity. Many of the early cases reported as IOBCC actually represent PA. Most of the well documented cases arise from the gingiva. The histologic features of basal cell carcinoma that help separate it from a PA include: tumor arising from surface epithelium, scattered mitotic figures and apoptotic cells, presence of mucoid ground substance and tumor infiltrating widely throughout the connective tissue and often exhibiting a prominent retraction artifact. Clinically IOBCC resemble carcinomas, compared to the benign and innocuous appearance of the PA and typically presents as surface ulcerations varying from rodent ulcer to an ulcerated erythroplakia appearance. This contrasts with the classic “bump on the gum” appearance of PAs with usually intact surface and appearing as small discrete, sessile, exophytic lesions. Importantly, the proliferative basaloid epithelium demonstrates positive immunoreactivity for the anti-epithelial antibody, Ber-EP4, a cell surface glycoprotein. The IOBCC has the potential for local recurrence and aggressive behavior and should be treated with wide surgical excision and close clinical follow up. We present 3 rare cases of IOBCC and discuss the salient histologic, immunohistochemical and clinical features.

Oral squamous cell carcinoma positive for p16/human papilloma virus in post allogeneic stem cell transplantation: 2 cases and review of the literature

Complications of allogeneic hematopoietic stem cell transplantation (allo-HSCT) includes the risk of secondary malignancies. This may be related to mechanisms including radiation and chemotherapy regimens, chronic graft-versus-host disease, inflammation, and prolonged imunosuppression. Oral squamous cell carcinoma (OSCC) is a complication associated with chronic graft-versus-host disease after allo-HSCT. Although human papillomavirus (HPV) is known to be associated with OSCC, the role of HPV in development of OSCC in post-HSCT patients has not been studied. We identified 2 cases of OSCC in allo-HSCT recipients. Both biopsy specimens tested positive for p16(INK4A), a surrogate marker for HPV. We propose that the association of OSCC and HPV in patients after allo-HSCT may not be incidental. Clinical implications of these cases may imply the need for a HPV screening, early intervention, and consideration of anti-HPV vaccination in this population. The effectiveness of such interventions could be validated in a prospective clinical study.

Glomus tumor: a comprehensive review of the clinical and histopathologic features with report of two intraoral cases

BACKGROUND Glomus tumors are benign neoplasms that most commonly present in the subungual region. Their occurrence in the oral cavity is exceedingly rare. Here, we present 2 cases from the oral cavity, detail their clinical and histopathologic features, and review the literature for solitary cases involving the oral regions. STUDY DESIGN The English language literature was queried for cases of benign glomus tumors in/around the oral cavity. Additional citations were cross-referenced from the identified sources. RESULTS Thirty-one cases of solitary glomus tumor in the oral and paraoral regions have been described, including the present cases. Patient age ranged from 10 to 85 years, with an average age of 47 years. In 12 of the 31 cases, the tumors occurred in the lips, 5 in the palate, 4 in the tongue, 4 in the buccal mucosa, 3 in the gingiva, and 1 each in the parotid, pterygoid fossa, and oropharynx. Only 18 of these cases had accompanying immunohistochemical stains, with 14 expressing positivity for muscle cell markers. CONCLUSIONS Although glomus tumors have distinct histopathologic features, diagnostic confusion may exist with regard to extradigital locations. Detailed documentation and discussion of the clinical and histopathologic features of rare tumors like these are vital to understanding them.

Common Lesions in Oral Pathology for the General Dentist

The specialty of oral and maxillofacial pathology encompasses identification and management of diseases in the mouth and surrounding structures. This chapter is a concise guide to some of the more common entities seen in the oral cavity involving both soft and hard tissues. The chapter will serve to provide basic clinical information and aid in recognition, diagnosis, and management of these common lesions. It is organized in a helpful manner for quick reference for the general dentist to identify pathologic lesions that a patient may present with.

Clear cell changes in salivary gland neoplasms: a 20-year retrospective study

Background Clear cells are observed histopathologically in both benign and malignant neoplasms but their presence in salivary gland tumors has not been extensively documented. Material and Methods With IRB approval, the archive of the University of Florida College of Dentistry oral pathology biopsy service was retrospectively searched from 1994-2014 for all benign and malignant salivary tumors. Epidemiological data, tumor location and duration, and type of tumor were recorded. A four reviewer panel examined the original slides. Reviewers scaled each case as 0 (no clear cells present), 1 (few to focal clear cells), 2 (less than 50% clear cells), and 3 (greater than 50% clear cells). Results A total of 535 cases were included of which 48% of tumors displayed 0 clear cells (257/535), 31.4% (168/535) scored 1, 13.6% (73/535) scored 2, and 7% (37/535) scored 3. Of the 251 (47%) malignant neoplasms, 64% (160/251) demonstrated 0-1 clear cell change, while 36% (91/251) showed a score of 2-3. For the total 284 (53%) benign tumors, 93% (265/535) scored 0-1 and 7% (19/535) scored a 2-3 range. No statistical difference was noted for gender, age, or duration of time present in regards to presence or absence of clear cells. Statistically significant differences in clear cell presence were found between location groups, between benign and malignant diagnosis, and between specific diagnostic groups. Conclusions This study demonstrates the frequent presence of increased numbers of clear cells in oral salivary malignancies and highlights salivary gland differential diagnoses when presented with clear cell changes. Key words:Clear cell change, salivary tumors, benign tumors, malignant tumors.

Merkel Cell Carcinoma of the Buccal Mucosa and Lower Lip

Merkel cell carcinoma (MCC) is an uncommon relatively aggressive neuroendocrine dermal neoplasm first described in 1972 as a tumor of the sun exposed skin. Although most MCC affect the skin of the head and neck, rare primarily oral mucosal cases have been documented. Merkel cells are nondendritic neuroendocrine cells that are found not only in the skin but also the oral mucosa and give rise to MCC. Neuroendocrine cells may be found as aggregates in organs or as diffuse or isolated cells within organs and their epithelial lining. They contain peptide hormones and biogenic amines and occur in two forms: dendritic, which are not associated with nerve fibers and non-dendritic, which are associated with nerve fibers. Merkel cells as well as MCC express simple epithelium-type Cytokeratins (8, 18, 19, 20), neurosecretory substances; chromogranin A, synaptophysin, neuron-specific enolase (NSE), adhesion molecules, and villin (intermediate filament). Though weakly, they also express neural markers such as S-100 protein. Cytokeratin 20, and Cluster of differentiation 56, are the two key diagnostic markers for Merkel cells and MCC. Etiology includes UV radiation, the recently described Merkel cell polyomavirus, and long term systemic immunosuppression. The cutaneous and mucosal variants of MCC are considered aggressive tumors with a high risk for local recurrence and metastasis and should be considered in the differential diagnosis of head and neck mucosal lesions. We present two cases of primary Merkel cell carcinoma, one on the buccal mucosa and the other on the lower lip, and discuss the salient histologic, immunohistochemical and clinical features.