Oral & Maxillofacial Pathology - Cairo University

🦷 CLINICAL CASE 2: The Pediatric Diagnostic Puzzle
We recently evaluated an interesting case involving a badly decayed primary tooth and an impacted permanent tooth. x-ray showed a large well-defined radiolucency. This creates a classic diagnostic dilemma: Is this an inflammatory periapical cyst caused by the severe infection of the deciduous tooth spreading downward, or is it a dentigerous cyst that originated developmentally around the permanent tooth and simply became infected?

Because the X-ray views overlap, making a definitive call radiographically is nearly impossible, meaning we must rely entirely on histopathology to solve the puzzle. Under the microscope, our oral pathology team looks for key microscopic clues: an inflammatory cyst will typically show a highly disrupted, irregular epithelial lining heavily infiltrated by inflammatory cells and cholesterol clefts, whereas a true dentigerous cyst—even an infected one—frequently retains areas of its classic, thin, 2-to-3-cell-layer of reduced enamel epithelium lining.

👇 To our fellow dentists and oral pathologists: When the X-ray is ambiguous, what specific histopathological features do you look for to differentiate an inflamed developmental lining from a purely inflammatory one? Let's discuss your diagnostic approach in the comments!

CLINICAL CASE CHALLENGE: Intrabony Maxillary Lesion

A 51-year-old female presents with a 1 to 2 cm intrabony lesion localized to the left maxillary region. CBCT imaging revealed a poorly defined radiolucency mixed with small internal radiopacities. Histopathological examination revealed trabeculae of dead bone with empty lacunae surrounded by granulation tissue which was heavily infiltrated with chronic inflammatory cells. Branching dilated fungal hyphae and spores were also detected. Areas of necrosis were also observed.

💬 To our OMFS and Oral Pathology Colleagues:
Given the presence of dilated, branching hyphae and spores within the necrotic bone, what is your primary differential diagnosis?
What special histochemical stains do you routinely rely on to differentiate between Mucorales and Aspergillus in tissue sections?

Let's discuss your diagnostic protocols below! 👇

🦷 Here’s the answer to the previous challenge case 👇

The diagnosis is Langerhans Cell Histiocytosis (LCH) 👀

The panoramic appearance together with the histopathologic features raised the suspicion of LCH, and the diagnosis was confirmed by positive immunohistochemical staining for CD1a 🧪✅

Histopathology typically shows characteristic “coffee-bean” grooved nuclei of Langerhans cells (yellow arrow), along with a prominent background of numerous eosinophils (Black arrow). 🔬
LCH is characterized by proliferation of pathologic Langerhans cells and may present in the jaws as osteolytic lesions with tooth mobility or the classic “floating teeth” appearance.

Common differential diagnoses included:
▫️ Lymphoma
▫️ Multiple myeloma
▫️ Metastatic lesions
▫️ Ewing sarcoma

Great answers and discussions from everyone 👏

🦷 Oral Pathology Challenge Case

47-year-old patient with a destructive mandibular lesion.
The panoramic radiograph and histopathology picture are attached. 👇

So… what do you think this lesion is? 👀
What differentials would be on your list?
And which IHC markers would you ask for to confirm the diagnosis? 🧪

Waiting for your opinions 👇

Thank you all for your insightful comments and great engagement on the previous post 🙏

As many of you correctly identified, the three gingival swellings correspond to the following histopathological entities:

🔹 Pyogenic Granuloma (EG)
Characterized by a lobular proliferation of capillaries lined by plump endothelial cells, often with an edematous and ulcerated surface. It is typically triggered by local irritation or hormonal influences.

🔹 Peripheral Giant Cell Granuloma (PGCG)
Distinguished by the presence of multinucleated osteoclast-like giant cells within a hemorrhagic fibrous stroma, frequently with hemosiderin deposition. A helpful radiographic clue is the classic “cupping” resorption of the underlying bone.

🔹 Peripheral Ossifying Fibroma (POF)
Shows a fibrous connective tissue stroma containing calcified or ossified material—this is the key diagnostic feature. It commonly arises from the interdental papilla and carries a notable recurrence risk if not excised down to the periosteum.

Excellent work to everyone who participated 👏

🔬 Spot Diagnosis Challenge — Three Gingival Swellings, Three Diagnoses!

Can you tell them apart?

All three lesions present clinically as gingival swellings and fall under the category of reactive lesions—yet each one has a distinct histopathological identity.

Attention, Dear Students and Pathologists! 📢
This is a collection of some of the most common odontogenic tumors. It will be highly beneficial

Today we’re highlighting two of the most common salivary gland tumors you’ll encounter.
👀 Swipe through the slides and challenge yourself… can you identify each one?
💬 Write the lesion name in the comments for each numbered image.

Hey students 👩‍⚕️👨‍⚕️

Ready to level up from cysts to something more challenging?

🔬 Histopathology Spot Diagnosis – Odontogenic Lesions

Examine the following microscopic images and determine the most accurate diagnosis based on the histopathological features.

Hey Students 👋

With exams just around the corner, we’re here to make your revision a little sharper, and a lot more interesting🧐

🔬 Histopathology Spot Diagnosis
Take a close look at the following microscopic images of odontogenic cysts and try to reach the correct diagnosis based on their characteristic features.

Share your answers in the comments ⬇️