Rare case of benign pleural fibrous experience

mesothelioma: A surgical

A n a n d Yadav , MS, San jay K u m a r , MS, San jeev Khulbe , MS, S a m e e r Sha rma , MS, Vikas Aha lwa t , MS, Raj K u m a r Yadav , M.Ch. , Ra j end ra M o h a n M a t h u r , M.Ch. , C h a n d r a P r a k a s h Shr ivas tva , M.Ch. S M S Medical College and Hospital, Jaipur

Introduct ion

Primary pleural tumors are rare as compared with metastatic lesions. These usually present with pleural effusion but nodular neoplastic masses without effusion or d i f fuse p leu ra l t h i cken ing do occur. L ipomas , endotheliomas, angiomas and cysts of the pleura are rare tumors and are usually seen on routine chest films as d e n s i t i e s f l a t t e n e d aga ins t the ches t wal l . Mesothel iomas arise fi'om cells that line the pleural, p e r i t o n e a l and pe r i c a rd i a l cavit ies . By de f in i t i on mesotheliomas arise from mesothelial cells. However because all th ree ge rm layers are i nvo lved in the format ion of the pleura their histologic appearance ranges from an almost pure spindle cell populat ion that resembles var ious o ther mesenchyma l tumors to a papillary and tubular pattern that appear epithelial in nature.

Localised benign fibrous mesothelioma is a rare entity and till date only 500 cases have been reported. These generally arise from visceral pleura (75%) but are known to arise from all portions of the parietal pleura including the mediastinal and diaphragmatic aspects. The tumors are usua l ly s ta lked but can be sessile and m a y be s u r r o u n d e d by l ung p a r e n c h y m a m a k i n g t h e m indistinguishable fi'om a pr imary bronchial lesion. Their size is variable and can range from small t u m o r to extremely large masses. They are smooth walled, may become partially calcified and contain fluid filled cysts. Histologically three patterns are known to occur fibrous or acellular, cellular and mixed.

These are extremely slow growing tumors and are usually asymptomatic. Patients become symptomat ic because of associated effusion or when the tumor grows

Address for Correspondence: Dr. Chandra Prakash Shrivastava H 16, Chitranjan Marg C Scheme Jaipur 302001, Rajasthan Tel : 0141 2560291 Ext. 475 Email : cps sms@hotmail.com @IJTCVS 097091342030904/052 Received 11/03/04; Review Completed 06/05/04; Accepted 06/05/04.

large enough to cause compression of the lung or a major airway. Pain is uncommon. Effusion is usually serous but can be haemorrhagic too. Hyper t rophic pu lmonary os teoar thropathy, hypoglycemia , coma and siezures occur in 20% cases with benign mesotheliomas larger then 7cm.

Diagnosis is usually made at operation for a solitary mass seen on chest film. The t u m o r is genera l ly a lobulated, peduncula ted mass. Blood is supplied to the t u m o r t h rough the pedicle and arises fi'om feeding bronchial, intercostal or diaphragmatic vessels. Therapy consists of complete excision and is curative. Recurrence is rare on long term follow up.

Case Report

Our" patient was a 30 year" old male non smoker w i th h is tory of ext remely s low growing painless swel l ing over" right infrascapular region of 18 year's duration. He started developing symptoms of breathlessness in early 2002 and underwent repeated pleural aspiration over a span of 11/2 year for recurrent pleural effusion. He gives past history of l ipoma excision fi'om the same site way back in 1983 in a peripheral hospital. He was subjected to fine needle aspiration cytology (FNAC) in 2003 which was inconclusive. He then u n d e r w e n t a C o m p u t e d tomographic (CT) scan and an endobronchial biopsy in the general surgery depar tment of our institution which labelled it as a case of non specific interstitial fibrosis. The pat ient was finally refer red to our depa r tmen t where he was taken up for surgery.

An extended right posterolateral thoracotomy was done through the 7th intercostal space (just above the tumor) and the giant, lobulated firm, sessile tumor of size approximate ly 10x8 cm was found arising from parietal surface of right pleura overlying 8th and 9th rib posterolaterally.

The ent i re r ight thoracic cavi ty was filled wi th s e r o s a n g u i n o u s ef fusa te and the lung was f o u n d completely collapsed. The tumor was excised along with adjacent portions of the under lying ribs. The chest was closed primarily. Drains were removed on day 3 and 5

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IJTCVS Anazld et al 143 2004; 20:142 143 Pleural mesothel ioma

and the pat ient had an uneventful post op recovery. Sutures were r emoved on day 10 and patient discharged within 2 weeks.

Histopathological evaluation It described the specimen as a solid nodular mass of

8x6x5 cm size, g rey ish whi te in colour and f i rm in cons is tency wh ich w a s wel l encapsu la ted . The cut surface showed greyish white lobules seperated by thin fibrous septa wi th areas of mucoid degenerat ion and some lobules revealed fibrillar appearance.

The diagnosis was fixed as solitary benign fibrous parietal pleural mesothel ioma.

D i s c u s s i o n

The case described is a rare enti ty I which usual ly presents as pleural effusion. Our case also gave history of ipsilateral chest wall swelling which is an u n c o m m o n a s s o c i a t i o n . P u l m o n a r y o s t e o a r t h r o p a t h y a n d h y p o g l y c a e m i a wh ich are found in 20% cases wi th tumors > 7 cm 2 were not found in our case. Most cases of benign mesothe l iomas are peduncu la ted and arise f rom visceral p leura but here it was found to be a sessile one arising from parietal pleura}

Diagnost ic d i l e m m a as regards site of origin and nature continued till excision as is evidenced by the case h i s to ry w h e r e at one s tage it w a s c o n s i d e r e d as a p u l m o n a r y lesion (Nonspecific interstitial fibrosis).

The long h i s t o r y d e m o n s t r a t e s e x t r e m e l y s low g r o w t h 3 and ben ign na tu r e of the t umo r . Surgica l t h e r a p y p r o v e d c u r a t i v e a n d e m p h a s i s e s e a r l y intervention in all cases.

C o n c l u s i o n

Case s t u d y d e m o n s t r a t e s i m p o r t a n c e of keep ing p l eu ra l p a t h o l o g y in m i n d whi l e dea l ing w i t h all per ipheral space occupying lesions of the thorax. A C T guided biopsy can serve as the best diagnostic tool and surgical excision should be employed as the definitive procedure in all cases at the earliest.

References

1. Oliara, Filosso PL, Casadio C, et al. Benign fibrous mesothel ioma of the pleura. Minerva Chir 1994; 49(12): 1311 16.

2. Trilomis T, Busch T, Sirbu H, Dalichau H. Giant localized fibrous mesothel ioma : An unusua l large intrathoracic tumor. Langenback Arch Chit2000; 385 (7): 482 84.

3. Vorphal U, Buhr J, Bohle RM, Berghauser KH, Hennek ing K. Localised benign pleural mesothel ioma. Langenback Arch Chir 1994; 3?9 (5): 30? 09.

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