Diapositiva 1

PULMONARY METASTASIS FROM SUBMANDIBULAR
BENIGN PLEOMORPHIC ADENOMA: REPORT OF A CASE
A. Pireddu, M. Spinelli, M. Giansanti, A. Sidoni, A. Cavaliere.
Istituto di Anatomia e Istologia Patologica
Università degli Studi, Perugia
INTRODUCTION

Metastasizing pleomorphic
extremely rare metastasis
tumour. Nevertheless, the
some cases indicates that
inappropriate.

Typically, the metastasis and the primary salivary
gland tumour are histologically identical to the
benign tumour.

We describe a case of pulmonary metastasis from
submandibular pleomorphic adenoma.
adenoma (MPA) is an
of histologically benign
aggressive outcome of
the adjective benign is
CASE HISTORY
A 51-year-old woman showed a lung nodule and two
pancreas lesions.
She had past medical history of pleomorphic
adenoma of the submandibular gland (7 years before)
locally recurred two years after diagnosis.
A computed tomography-guided needle biopsy of the
pulmonary nodule was performed.
PATHOLOGICAL FINDINGS
The histologic exam of formalin-fixed and paraffin
embedded tissue evidenced a neoplasm made up of
small cells with no atipia in a variable amount of
fibromyxoid tissue.
IMMUNOHISTOCHEMICAL
FEATURES

The cells were immunoreactive for cytokeratin pool,
smooth muscle actin and S-100 protein.

They were negative for chromogranin, synaptophysin
and TTF-1.

The proliferative index Ki-67 (MIB-1) was 3%.
CYTOKERATIN POOL
S-100 PROTEIN
SMOOTH MUSCLE ACTIN
DISCUSSION 1
 MPA was first described in 1942.
 The mechanism underlying its metastatic
behaviour is still not certain.
 The majority of the tumours origins from the
parotid gland, while there are a few reports
of metastasis from the submandibular gland.
DISCUSSION 2
 Bone, lung and lymph nodes are the most
common sites of metastatic disease, but
kidney, liver, CNS, retroperitoneum and skin
can also be involved.
 As in our case, there is often a long interval
between diagnosis of the primary tumour
and metastases.
BIBLIOGRAPHY
Czader M, Eberhart CG, Bhatti N, Cummings C, Westra
WH. Metastasizing mixed tumor of the parotid: inizial
presentation as a solitary kidney tumor and ultimate
carcinomatous transformation at the primary site.
Am J Surg Pathol, 24:1159-1164, 2000
Raja V, China C, Masaki KH, Nakano G. Unusual
presentations of uncommon tumors: case 1. Benign
metastasizing pleomorphic adenoma.
J Clin Oncology, 20:2400-2403, 2002
Sit K Y, Chui W H, Wang E, Chiu SW. Multiple pulmonary
metastases from benign pleomorphic adenoma.
Asian Cardiovasc Thorac Ann, 16:62-4, 2008