Balasubramanian M.S. D.L.O.
Synonyms: Schneiderian papilloma, Benign papilloma
of nasal cavity, Inverted papilloma.
The mucosal lining of nose and para nasal sinuses is known as
Schneiderian membrane, in memory of Victor Conrod
Schnider who described its histology. Papillomas
arising from this membrane is very unique in that they are
found to be growing inwardly and hence the term inverted
papilloma. These papillomas are unique in their history,
biology and location.
Papillomas involving the vestibule is
not included under this group because histologically, biologically
and behaviour wise it is different.
The lining mucosa of nose
and paranasal sinuses is unique embryologically in the
sense that it is derived from the ectoderm, in contrast to the
lining epithelium of laryngobronchial tree which is derived from
behave like neoplasms, arising from reserve / replacement cells
located at the basement membrane of the mucosa. The stimulus
for this proliferation is unknown. The resulting thickening of
the epithelium assumes an inverting, fungiform or combination
growth pattern. Depending on the degree of metaplasia varying
amounts of respiratory / cylinderical cells may be seen in
schneiderian papilloma. Rarely the papilloma may be composed
entirely of cylinderical cells, and hence the term cylinderical cell
papilloma is used to describe this subtype.
classification of Schneiderian papilloma: Inverted
papilloma can be classified according to its site of occurance i.e.
lateral wall and septal papillomas. They show
differences in their behavior patterns. The septal papillomas
remain confined to the nasal septum and may very rarely involve
the roof and floor of the nasal cavity. Carcinomatous
transformation is rare in septal papillomas.
Papilloma of lateral
wall is known to involve multiple sites i.e. floor, roof of nasal
cavity, para nasal sinuses and naso lacrimal
duct. Carcinomatous transformation is common in this
Incidence: Inverted papillomas are
fairly common occurring in 1 - 50 of patients with nasal
polypi. If all nasal polypi removed surgically are tested
histopathologically then the incidence could be still more
higher. Men are affected more commonly than women. The
age of affliction may range from between second to seventh decade of
life. The mean age of presentation being 50.
Etiology: Human papilloma virus has been implicated
as a causative factor in these patients. This infection
in association with mutation of
genes may cause papillomas. Coinfection with Herpes simplex virus may
interact with Human papilloma virus to cause inverted papilloma.
Gross appearance of inverted
Gross apprearance: Nasal papillomas
show two architectural patterns: 1. Papillary and exophytic 2.
Inverted with inwardly invaginating epithelial growth into
underlying stroma. A combination of both patterns also
can occur. The papillary form tends to commonly occur in the
nasal septum, while the inverted form often occurs in the lateral
wall of the nose and sinuses.
papillary form also known as fungiform papilloma shows epithelial
proliferation over a thin core of connective tissue. Inversion
of epithelial masses is usually not present. In the case
of inverted papilloma the predominant growth is directed inwards
into the underlying stroma. The stroma is not breached in
these patients. When they undergo malignant
transformation the stroma is found to be breached. The
predominant cell type in these papillomas is epidermoid in
nature. Intercellular bridges can be clearly
demonstrated. Microscopic mucous cysts can also be identified
in both these types. Keratinisation is very minimal.
Excessive keratinisation is very rare, and should prompt the
pathologist to other diagnosis like malignant
Clinical features: Patients
present with unilateral nasal mass, commonly fleshy in nature.
Sometimes it may occur behind a sentinel nasal polyp. It
commonly involves the nasal cavity, erodes the medial wall of
maxilla and may present inside the maxillay
1. Unilateral nasal obstruction
3. Nasal discharge
4. Proptosis if lamina
papyracea is breached
Patient with inverted papilloma of
right nasal cavity
Management: Surgical removal
provides cure in most of the cases. Recurrence is common in
20% of patients. It is commonly removed pervia
naturalis. If the mass is huge then lateral rhinotomy will
have to be resorted to for complete
site contents © Copyright drtbalu 2006, All rights