Rhinolith

A rhinolith (from the Ancient Greek ῥίς — “nose” and λίθος — “stone”) is a dense, stone-like mass (concretion) that forms within the nasal cavity due to the gradual deposition of mineral salts around a central nidus. This condition is relatively rare, develops slowly over many years, and is most commonly diagnosed in adults — although the initial nidus often enters the nasal cavity during childhood.

Typically, rhinoliths are unilateral. As they grow bigger, they may cause progressive obstruction of the nasal passages and chronic inflammation, mimicking symptoms of other nasal pathologies.

Aetiology and pathophysiology

A rhinolith begins to form when a central nidus (matrix) emerges within the nasal cavity. Over time, inorganic salts — primarily calcium and magnesium phosphates and carbonates found in nasal secretions — are deposited around this nidus in concentric layers. Chronic inflammation, triggered by the foreign body, exacerbates the condition.

The nidus may be:

• Exogenous (external origin): Most commonly, a nidus is a foreign object introduced during childhood and left undetected, such as a bead, berry seed, fragment of paper or cotton, or button.
• Endogenous (internal origin): A nidus may form from a blood clot, dried mucus, desquamated epithelial cells, a dislodged tooth, or a bone sequestrum.

As the rhinolith enlarges, it conforms to the shape of the nasal cavity and may exert pressure on adjacent structures, including the nasal septum and sinus walls.

Clinical Significance

In the early stages, a small rhinolith may be asymptomatic. Unilateral in nature, symptoms typically emerge as the mass grows.

Primary symptoms include:

• Progressive unilateral nasal obstruction.
• Persistent, unilateral mucopurulent or purulent discharge, often with a foul odor (cacosmia).
• Intermittent epistaxis due to mucosal erosion.
• Headaches, facial pressure, or pain localized to the affected side.
• Reduced sense of smell (hyposmia).

Diagnosis is based on medical history and physical examination. Anterior rhinoscopy may reveal a gray or dirty-brown stony mass covered with pus or granulation tissue. Its hard consistency is confirmed with a bulb-headed probe. Computed tomography (CT) of the paranasal sinuse is considered the diagnostic gold standard, which accurately visualizes the size, shape, and location of the calcified mass.

Surgery is the only option to completely remove the rhinolith from the nasal cavity. An endoscopic procedure under local or general anesthesia is generally performed.

Differential Diagnosis

The clinical manifestations of a rhinolith (unilateral obstruction and foul-smelling discharge) necessitate thorough differential diagnosis, primarily to exclude malignant nasal tumors. A healthcare provider should also rule out any other conditions, such as long-standing non-calcified foreign bodies, fungal masses (mycetoma), which may also contain calcifications, and specific infections such as syphilis or tuberculosis. Note that the characteristic appearance of a dense concretion on CT and its stony hardness upon probing allow reliable differentiation from other pathologies.