ovarian cancer has the highest mortality rate of all gynaecologic malignancies in europe and in the united states . this happens primarily because ovarian cancer presents at a relatively advanced stage of the disease . dissemination of ovarian cancer is most common by the intra - peritoneal route so that in the majority of patients disease most frequently remains confined to the peritoneal cavity . nevertheless , ovarian cancer may also metastasize through lymphatic channels ; for this reason a lymph node metastasis classification has been introduced into the figo staging . the prognostic significance of lymph node metastasis(es ) in ovarian cancer is still controversial   and researchers have paid most attention to investigating the prognostic impact of para - aortic lymph node metastasis . indeed , very few papers describe extra - abdominal lymph node involvement in this type of tumour [ 5 , 6 ] . positron emission tomography ( pet ) with [ f]fluoro-2-deoxy - d - glucose ( fdg ) has emerged as an extremely useful technique in clinical oncology . a high accuracy of f - fdg pet has been proven for evaluating patients with ovarian tumours , both for the assessment of ovarian neoplasms before treatment and for the evaluation of cancer recurrence [ 7 , 8 ] . recently hybrid pet / computed tomography ( ct ) has been introduced in clinical practice , combining the information derived from the functional imaging of f - fdg pet with the detailed morphological data of ct . preliminary reports indicate a potential usefulness of this technique for the precise identification of cancer spread . in particular , in ovarian cancer f - fdg pet / ct was found to be particularly useful in identifying abdominal recurrence . f - fdg pet / ct allowed us to identify extra - abdominal lymph node involvement in the left supra - clavicular space . each patient , fasted for at least 6 h , was intravenously injected with 5.3 mbq /kg of f - fdg ; images were recorded 6090 min after tracer administration using a discovery ls - st4 scanner ( general electric medical system , waukesha , wi ) . the ct parameters were as follows : 140 kv , 90 ma , 0.8 s per tube rotation , 30 mm table speed per gantry rotation . multi - slice technology allowed the acquisition of four slices per tube rotation with a thickness of 5 mm . pet studies were performed acquiring 4 min of emission data per bed position and 35 transaxial images were reconstructed for each bed . scaled ct images were used for non - uniform attenuation correction of pet emission scans . pre - surgical diagnostic work - up included abdominal - pelvic ct and ultrasound ; a large pelvic mass likely originating from the left ovary was depicted . at laparoscopy a 10 cm mass characterised by a combination of solid and cystic areas with involvement of both annexials was found . the patient was operated on by laparotomy , and total hysterectomy plus bilateral annexial resection and peritoneal washing were performed . histology indicated a poorly differentiated cancer , infiltrating the myometrium ; the peritoneal fluid was positive for cancerous cells . the patient was then scheduled for chemotherapy . before an f - fdg pet / ct scan pet / ct revealed multiple sites of increased glycolytic metabolism in lymph nodes : iliac bilaterally , left lumbar , para - caval and also left supra - clavicular / latero - cervical ( figs 1 and 2 ) . the presence of supra - clavicular lymph nodes was confirmed by ultrasound and ct , and the final diagnosis of metastatic ovarian cancer was reached by biopsy . the patient was then treated by chemotherapy ( carboplatin plus taxol plus topotecan ) obtaining a good response ( a reduction of ca125 from 273 to 14 ) . a 65-year - old patient was admitted to our hospital in july 2003 for complete staging and subsequently surgery for a pelvic tumour . ultrasound demonstrated the presence of a pelvic mass with non - homogeneous echogenicity ; abdominal - pelvic ct confirmed the presence of a large mass ( 171214 cm ) and also showed lymph nodal involvement at para - aortic , para - caval , retro - crural levels . pet / ct showed an intense radio - tracer uptake in the pelvic mass , and also revealed multiple hypermetabolic lymph nodes in the para - aortic , para - caval , retro - crural and left supra - clavicular regions ( figs 3 and 4 ) . the patient was then operated on by laparotomy , with mass excision and bilateral annexiectomy . each patient , fasted for at least 6 h , was intravenously injected with 5.3 mbq /kg of f - fdg ; images were recorded 6090 min after tracer administration using a discovery ls - st4 scanner ( general electric medical system , waukesha , wi ) . the ct parameters were as follows : 140 kv , 90 ma , 0.8 s per tube rotation , 30 mm table speed per gantry rotation . multi - slice technology allowed the acquisition of four slices per tube rotation with a thickness of 5 mm . pet studies were performed acquiring 4 min of emission data per bed position and 35 transaxial images were reconstructed for each bed . scaled ct images were used for non - uniform attenuation correction of pet emission scans . a 51-year - old patient was operated on june 2003 for a pelvic tumour . pre - surgical diagnostic work - up included abdominal - pelvic ct and ultrasound ; a large pelvic mass likely originating from the left ovary was depicted . at laparoscopy a 10 cm mass characterised by a combination of solid and cystic areas with involvement of both annexials was found . the patient was operated on by laparotomy , and total hysterectomy plus bilateral annexial resection and peritoneal washing were performed . histology indicated a poorly differentiated cancer , infiltrating the myometrium ; the peritoneal fluid was positive for cancerous cells . the patient was then scheduled for chemotherapy . before an f - fdg pet / ct scan pet / ct revealed multiple sites of increased glycolytic metabolism in lymph nodes : iliac bilaterally , left lumbar , para - caval and also left supra - clavicular / latero - cervical ( figs 1 and 2 ) . the presence of supra - clavicular lymph nodes was confirmed by ultrasound and ct , and the final diagnosis of metastatic ovarian cancer was reached by biopsy . the patient was then treated by chemotherapy ( carboplatin plus taxol plus topotecan ) obtaining a good response ( a reduction of ca125 from 273 to 14 ) . a 65-year - old patient was admitted to our hospital in july 2003 for complete staging and subsequently surgery for a pelvic tumour . ultrasound demonstrated the presence of a pelvic mass with non - homogeneous echogenicity ; abdominal - pelvic ct confirmed the presence of a large mass ( 171214 cm ) and also showed lymph nodal involvement at para - aortic , para - caval , retro - crural levels . pet / ct showed an intense radio - tracer uptake in the pelvic mass , and also revealed multiple hypermetabolic lymph nodes in the para - aortic , para - caval , retro - crural and left supra - clavicular regions ( figs 3 and 4 ) . the patient was then operated on by laparotomy , with mass excision and bilateral annexiectomy . ovarian cancer tends physiologically to metastasise via the lymphatic channels , mainly the intra - peritoneal route and understanding of the sites of spread is crucial for disease treatment . lymphatic diffusion of ovarian cancer is commonly retained to involve mainly pelvic lymph nodes and , subsequently , retro - peritoneal lymph nodes . data from the literature concerning extra - abdominal lymph node involvement are very poor . in this respect , it is worth noting that a recent review on this topic did not take into account the prevalence of extra - abdominal positive nodes . conversely , cormio and colleagues   reviewed 162 patients with epithelial ovarian carcinoma and reported five cases of extra - abdominal lymphatic spread . interestingly , zang and colleagues   described their 10-years of experience of patients with ovarian cancer presenting initially with extra - abdominal metastases and reported a significant number of cases with supra - clavicular and inguinal lymph nodes metastases ( 6 and 5 cases , respectively ) . apart from these two papers , a case report described left internal mammary lymph node involvement in a patient with serious borderline ovarian tumour ; two cases of intra - mammary lymph node metastases were described : in a case of early - staged ovarian cancer   and in a case of a borderline papillary ovarian tumour . lastly , we found few cases of axillary lymph nodes calcification in patients with metastatic ovarian carcinoma . these sporadic reports in the literature clearly indicate that extra - abdominal lymph node spread in ovarian cancer is possible although rare . on the basis of our findings , it may be speculated that f - fdg pet / ct is a useful tool and it may be particularly useful to detect unusual extra - abdominal nodal involvement in ovarian cancer . further studies on a higher number of patients are required to elucidate the potential role of f - fdg pet / ct in evaluating lymphatic metastatic spread of ovarian cancer . f - fdg pet / ct scan showing multiple sites of increased fdg uptake in abdominal lymph nodes but also in the left supra - clavicular region .     f - fdg pet / ct scan : ( a ) ct image , ( b ) pet image , ( c ) fusion pet / ct image . focal area of highly increased fdg uptake is shown in the left supra - clavicular lymph nodes . f - fdg pet / ct scan revealing increased fdg uptake in the pelvic mass and in multiple abdominal lymph nodes ( para - aortic , para - caval , retro - crural ) , but also in the left supra - clavicular lymph nodes . f - fdg pet / ct scan : coronal images , ( a ) ct image , ( b ) pet image , ( c ) pet / ct fusion image . a focal area of intense fdg uptake is shown in the left supra - clavicular lymph nodes .
tumoral dissemination of ovarian cancer most commonly occurs through the intra - peritoneal route ; nevertheless , although it is rare , ovarian cancer may also metastasise through the lymphatic channels . 
 lymphatic diffusion of ovarian cancer usually involves pelvic and retro - peritoneal lymph nodes . 
 extra - abdominal lymph nodes are rarely involved and their detection may represent a challenge for the oncologist . 
 we describe here two patients studied for ovarian cancer by [ 18f]fluoro-2-deoxy - d - glucose ( 18f - fdg ) positron emission tomography ( pet)/computed tomography ( ct ) : one case during pre - operative staging , the other for restaging after surgery . in both cases 
 pet examination identified extra - abdominal lymph node tumoral spread in the left supra - clavicular space ; biopsy led to a final diagnosis of recurrent ovarian cancer . 
 previous reports in the literature on tumoral spread of ovarian cancer to the supra - clavicular nodes are rare , however this possible site of metastatic involvement has to be kept in mind by oncologists and our data show that the 18f - fdg pet / ct may be useful to disclose this unusual supra - diaphragmatic lymphatic diffusion of metastatic lymphatic ovarian cancer .