Primary fallopian tube carcinoma

Primary fallopian tube carcinoma (PFTC) is an extremely rare malignancy that arises from the fallopian tube. They account for ~1 (0.2-1.1)% all gynaecological malignancies (least common of all gynaecological malignancies ³).

Epidemiology

The estimated incidence is at ~3-4 per million women ³. It typically present in post menopausal females (peaks at 6^th-7^th decades).

Clinical presentation

Most patients are asymptomatic or tend to present with non specific or insiduous symptoms. The symptoms complex comprising of an intermittent profuse serosanguineous vaginal discharge, colicky lower abdomino-pelvic pain relieved by the vaginal discharge, and an adnexal mass can be present in ~15% of and is termed the Latzko triad^13-14. 

Pathology

Most primary fallopian tube cancers arise from ampulla with endoluminal growth that leads to obstruction and distension of the fallopian tube (hydrosalpinx), which explains why the majority of these patients are rarely asymptomatic in contrast with those with ovarian cancer. 

Tumours can be bilateral bilateral in 20% of the cases, mainly in advanced disease. 

The pattern of growth can be nodular, papillary, infiltrative, or mass forming. 

Recognised histological types include:

• papillary serous adenocarcinoma of fallopian tube
  • most common histological sub type
  • can be histologically identical to a serous cystadenocarcinoma of the ovary.
• endometrioid carcinoma of the fallopian tube
• transitional cell carcinoma of the fallopian tube

Location 

The tumour usually originates in the ampulla of the Fallopian tube. Bilateral involvement can in been is ~20% of cases ¹.

Markers

Serum CA-125 levels are often elevated ^6,8.

Radiographic features

Advanced tumours are difficult to differentiate from ovarian tumours on imaging. The presence of a hydrosalpinx can be a useful feature.

Ultrasound

While being non specific, it may be sonographically identified as a complex cystic mass involving the fallopian tube with papillary projections ^10-11. 

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MRI

While signal characteristics are not specific, they generally are as follows ^1,3

• T1
  • solid tumour portion is is usually of low signal 
  • if there is an associated simple serous fluid containing hydrosalpinx this may be low signal 
  • if there is an associated simple haemorrhagic fluid containing hydrosalpinx this may be high signal 
• T2
  • solid tumour component is often homogeneously or heterogeneously low or of intermediate signal  
  • if there is an associated simple serous fluid containing hydrosalpinx this may be of high signal
• T1 C+ (Gd): solid portion often demonstrates enhancement 

Staging 

See:staging of primary fallopian tube carcinoma

Treatment and prognosis

Compared with ovarian carcinoma, fallopian tube cancer more tends to present at an earlier stage but has a worse prognosis, stage for stage ². The reposted better overall survival therefore may be on the basis of earlier stage at presentation ⁴. Treatment generally consists of surgical debulking followed by chemotherapy.

Differential diagnosis

For a mass involving the fallopian tube, differential considerations would be:

• tubal ectopic pregnancy: women of childbearing age and BHCG evelated
• primary ovarian cancers (especially ovarian epithelial tumours) with involvement of the fallopian tubes
• infective of inflammatory conditions
  • pelvic inflammatory disease +/- pyosalpinx