Unveiling the Mysteries of Ameloblastoma: A Comprehensive Case Series on Odontogenic Lesions

ABSTRACT

Ameloblastoma is a benign yet locally invasive odontogenic tumor arising from remnants of the enamel organ or dental lamina, typically manifesting as painless jaw swelling associated with impacted teeth. Its marked histopathological heterogeneity necessitates precise diagnosis to avert recurrence. This case series presents four diverse ameloblastoma variants, including conventional, unicystic (luminal and mural), and a rare mimic of a lateral periodontal cyst. Clinical, radiographic, and histological evaluations were conducted, revealing hallmark features such as peripheral palisading, stellate reticulum-like zones, and cystic degeneration. The findings highlight the indispensability of integrated diagnostic protocols and timely surgical intervention for effective management.

INTRODUCTION

Ameloblastoma is a rare benign but locally aggressive odontogenic tumor that occurs from the remnants of the dental lamina or the developing enamel organ.[1,2] It usually presents in the form of painless swelling of the jaw and is frequently found to be associated with impacted teeth.[3] This case series describes four cases diagnosed with ameloblastoma and associated odontogenic lesions, highlighting their clinical presentation, histopathological features, and differential diagnoses.

CASE SERIES

Case 1

A 45-year-old man has had swelling in the right side of his face for 1 year. On examination, a hard, sessile, non-fixed swelling over the right lower posterior segment was found. It was not tender on palpation, and impacted 47; 48 were found. The provisional diagnosis was ameloblastoma. Histopathological study showed ameloblast-like tumor cells in irregular masses and interconnecting strands, demarcated by peripheral columnar cells with reversal of polarity mimicking ameloblasts. Cystic degeneration was seen in the central stellate reticulum-like cells. The connective tissue was hyalinized with dilated blood vessels, giant cells, calcifications, and inflammatory infiltrates. The tumor was at the anterior, superior, and posterior margins, and the distal to 48 tooth region, but tissue around 48 tooth region lacked tumor islands.

Case 2

A 38-year-old woman reported swelling on the left side of her face for 6 months. The swelling occurred suddenly and gradually increased in size. The patient had a history of penicillin allergy and wheezing for 13 years. On examination, there was a soft, fluctuant, sessile, tender swelling in the buccal vestibule beside 35-37. OPG revealed a multilocular radiolucency from the distal side of 34 to the mesial side of 37; 36 was missing. The provisional diagnosis was a lateral periodontal cyst. Histopathology revealed a cystic cavity lined by a few epithelial layers with reversal of polarity in the basal layer and hyperchromatism. Superficial cells were stellate reticulum-like. The underlying connective tissue was moderately collagenous with fibroblasts, endothelial-lined capillaries, extravasated red blood cells (RBCs), odontogenic epithelium, inflammatory infiltrate, and osteoid tissue. These histopathological features were in concordance with the diagnosis of ameloblastoma.

Case 3

A man aged 50 years had a mobile tooth in the lower back left region for 1 week and pain for the last 2 days. The suspected diagnosis was unicystic ameloblastoma or dentigerous cyst. Microscopic section revealed a cystic space lined by two to three flat epithelial cells resembling reduced enamel epithelium. The connective tissue was densely collagenous, with fibroblasts, blood vessels, and extravasated RBCs. Multiple ameloblastic follicles were observed, with peripheral tall columnar cells showing nuclear hyperchromatism, reversal of polarity, nuclear palisading, and subnuclear vacuolization. The central cells were stellate reticulum in appearance with squamous metaplasia and cystic degeneration foci. Diagnosis was unicystic ameloblastoma (mural type).

Case 4

A 55-year-old man with a 40-year history of smoking reported a cystic lesion in the mandible. Grade I mobility of 48, 47, and 45 was found on examination, along with a well-defined cystic lining (29 × 22 mm) in the region of missing 46. OPG demonstrated a well-defined unilocular radiolucency with irregular margins from 45 to the distal root of 47, with loss of cortication and lamina dura. The provisional diagnosis was a dentigerous cyst. Histopathology revealed a cystic lumen lined by stratified squamous epithelium, basal cuboidal and columnar cells having hyperchromatic nuclei and reversal of polarity. The superficial layers demonstrated loss of cohesiveness like stellate reticulum. The connective tissue was densely collagenous with fibroblasts, capillaries, giant cells, cholesterol clefts, and dense inflammatory infiltrate. Adipocytes, bone, and extravasated RBCs were noted. Diagnosis established unicystic ameloblastoma (type luminal) [Table 1 and Figure 1].

Table 1.

Comparison of clinical, provisional, and final diagnoses in ameloblastoma cases

Case	Clinical features	Provisional diagnosis	Why considered	Differential diagnosis	Final diagnosis (HP diagnosis)
1	Right facial swelling for 1 year, impacted 47, 48	Ameloblastoma	Hard, sessile swelling, impacted teeth	Odontogenic keratocyst, central giant cell granuloma	Ameloblastoma
2	Left facial swelling for 6 months, multilocular radiolucency, missing 36	Lateral periodontal cyst	Fluctuant swelling, multilocular radiolucency	Odontogenic keratocyst, ameloblastoma	Ameloblastoma
3	Mobile tooth, pain for 2 days	Dentigerous cyst/Unicystic ameloblastoma	Mobile tooth with pain, cystic radiolucency	Odontogenic keratocyst, radicular cyst	Unicystic ameloblastoma (Mural type)
4	Smoking history, cystic lesion near missing 46, unilocular radiolucency	Dentigerous cyst	Well-defined radiolucency, cortication loss	Residual cyst, odontogenic keratocyst	Unicystic ameloblastoma (Luminal type)

HP=Histopathology

Figure 1.

The figure above presents a compilation of histopathological images corresponding to four different cases of odontogenic lesions. From left to right, the images depict: Cases 1, 2, 3, 4

DISCUSSION

Ameloblastoma is locally invasive, but benign with a high recurrence rate. It exists as painless swelling and, most commonly, impacted teeth.[4,5] In all cases, the presence of swelling, radiolucency, and impacted or missing teeth suggested various odontogenic pathologies. Ameloblastoma was suspected in cases with hard, sessile swellings and multilocular radiolucencies, while dentigerous cysts were considered for well-defined, corticated lesions near impacted teeth.[1,2] Odontogenic keratocyst (OKC) was a key differential due to its aggressive nature and cystic presentation, while radicular and residual cysts were included based on inflammatory response and extraction history.[3,4] Histopathological proof is indispensable for differentiation from other odontogenic lesions.[6] Various histopathological forms have been highlighted in this case series, adding to the literature, such as solid ameloblastoma, unicystic ameloblastoma (mural type and luminal type), and ameloblastoma mimicking lateral periodontal cysts.

CONCLUSION

The diverse histopathological presentations of ameloblastoma require precise diagnosis and proper surgical management to avoid recurrence. Follow-up is mandatory to predict the possible recurrence and/or malignant transformation of such lesions. This paper highlights the need to combine clinical, radiographic, and histopathological information for the proper management of odontogenic lesions.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and that due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.