Introduction
Billroth was the first to describe “Multiple Primary Malignancy (MPM)” more than a century back.1 Later Warren and Gates coined the term MPM and categorised into 2 types: synchronous and metachronous. Being a rare entity, the incidence of multiple cancers had progressively increased over time in the recent past.2
While the term metachronous is applied when tumours follow one another after a period of six months, synchronous is defined as tumours arising simultaneously or within 6 months from the primary malignant tumour.2 The former has higher incidence than the later in terms of frequency with an average incidence of 2:1.3
Currently, there is no accepted consensus on the criteria to define synchronous tumour.4 Few researchers suggested proposals which include,
Two or more histologically different malignancies and detected simultaneously
Two or more histologically distinct malignancies diagnosed during the same time admitted in the hospital
Two or more histologically distinct malignancies arising from the same system of origin with a sequence gap of minimum 2 months duration
Metastatic lesions among these tumours must be excluded
Several the ories had been proposed on the factors that influence the occurrence of MPM like elderly age, male gender, family history, genetic predisposition and precursor lesions. MPM is pre dominantly observed among the gastrointestinal system especially in colorectal and always has a tendency to occur below diaphragmatic sites.5 Apart from GIT, MPM is known to involve breast, renal system and lung. MPM involving the parotid gland as one component in adjunction with GIT malignancy (especially duodenal carcinoma) as another component is an extremely rare phenomenon.6
In the present case scenario, we had an elderly male with synchronous tumor as a rare and unique presentation.
Case presentation
A 68 years old male patient presented with painless swelling in the left cheek of 2 months duration with gradual increase in size. He also gave history of left axillary swelling of one and a half months duration. He had loss of appetite and significant weight loss in the past 2 months. He was a known hypertensive.
On examination, there was a left preauricular swelling of 6x4 cm size (Figure 1). The swelling was nodular, firm, with neither warmth nor tenderness. Skin over the swelling was normal. Horizontal mobility was more than vertical mobility. Right axilla showed a solitary firm swelling measuring 3x3 in diameter.
As a screening procedure for any superficial swelling, the patient was subjected to Fine Needle Aspiration Cytology procedure (FNAC) for the parotid and axillary swelling. Cytological picture of the parotid swelling revealed features of m ucoepidermoid carcinoma (MEC) of salivary gland (Figure 2) and cytology of axillary swelling showed features of metastatic carcinomatous deposits from MEC (Figure 3). Subsequent excision biopsy of axillary swelling showed classical metastatic deposits from MEC (Figure 4). Since the patient gave history of loss of appetite, vomiting, abdominal pain and significant weight loss, pan endoscopy procedure was performed which revealed an ulcerative growth in duodenum and its histopathological picture proved to be adenocarcinoma of duodenum (Figure 5). Thus the patient proved to be a case of MPM with synchronous nature presenting with less than six months duration.
Figure 2
Smears from aspirate of preauricular swelling showing small clusters of intermediate cells in a background of blood mixed mucin. Pap, 40X
Figure 3
Fine needle aspiration smears from axillary lymph node showing deposits of Mucoepidermoid carcinoma. MGG, 40X
Discussion
The term MPM earlier entitled as ‘Second primary malignancy or dual malignancy’ was known even ten decades back.6 Literature search states that colorectal cancers will be definite component along with genital or urinary cancers often having precursor lesions especially Here ditary Non Polyposis Colorectal cancers (HNPCC).7 Studies had observed the incidence of MPM as 7-9% worldwide and 6-9% among all cancers in Tropical countries like India with annual increase in incidence7,8
The tendency of some patients to develop MPM (synchronous or metachronous) may be explained by the action of carcinogenic factors acting on different organs at different times.8 This could be the explanation regarding the association between slow growing and aggressive tumours, as reported in our case.
With regard to MPM, age factor is an uncertain parameter, as several studies have indicated that synchronous tumours occur in older patients,9 while few studies observed among younger patients. However the usual age incidence ranges bet ween 45–75 years of age with median age of 55 years.
Majority of the cases diagnosed synchronously were incidental during staging work up of the primary tumour. Very few patients will have complaints attributable to the second primary tumour. Most common challenge encountered by practitioners is to label such tumour to be metastatic in nature, often obviating the rare possibility of a second primary tumour. Multiple tumours that have been microscopically confirmed at the time of presentation should be evaluated and staged as independent tumours.9,10
Salivary gland tumours commonly known to occur in parotid region and are usually benign than malignant. While Mucoepidermoid carcinoma of salivary gland is a relatively rare condition it is well known to have metastatic spread to cervical lymph node. Surprisingly in the present case, the patient had metastatic deposits to axillary node which was confirmed histopathologically.11
While colorectal carcinoma is a well-known M PM component, the incidence of duodenal carcinoma as MPM component is rarely reported in literatures. While GIT cancers spread to supraclavicular node above the diaphragm, metastasis to axillary region is still an unique presentation.11,12
Luciani etal stated that salivary gland as a component is extremely rare, even if involved acinic cell carcinoma and Warthins tumour are only reported in the literatures.12 MEC in adjunction with duodenal adenocarcinoma as synchronous tumour is a rare combination ever reported in the literatures. It is evident from the present case that synchronous tumour can also involve salivary gland with MEC as a component thereby warranting further exploration of MPM especially in supradiaphragmatic lesions.10,12
The treatment plan should be decided after staging of both the primary and secondary tumour in view to attain maximum clinical response. Proper counselling and patient’s understanding of the magnitude of the disease is paramount. Single stage surgery can be offered to treat both the tumour if indicated in majority of cases with low morbidity and mortality.
Critical appraisal and uniqueness of the case
Synchronous tumour involving salivary gland with GIT is extremely rare. Mucoepidermoid carcinoma in conjunction with duodenal adenocarcinoma is a unique presentation. To our knowledge on synchronous tumour, no case in literature has so far mentioned the occurrence of MEC of salivary gland tumour in adjunction with duodenal a denocarcinoma and salivary gland tumour metasizing to axillary node is also a rare phenomenon.
Conclusion
MPM can present in elderly males with supradiaphragmatic component as well. Strong clinical acumen and suspicion are required to identify cases of MPM and to differentiate them from metastatic disease. Synchronous tumour is known to occur among colorectal region as the most common presentation. Mucoepidermoid carcinoma of salivary gland with duodenal adenocarcinoma makes this case report unique. The preoperative detection of synchronous tumours not only allows establishing the appropriate surgical strategy, but also facilitates the follow-up plan after surgery.
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