Ovaries, fallopian tubes and associated lesions

CHAPTER 27 Ovaries, fallopian tubes and associated lesions

Sanjiv Manek, Vesna Mahovlić

Introduction

The application of cytological techniques such as fine needle aspiration (FNA) in the routine diagnosis of ovarian lesions used to be limited, particularly for malignant neoplasms, but is now less so with the advent of accurate imaging and the introduction of key monoclonal antibodies for immunocytochemistry. When judiciously employed, FNA of cystic lesions in the pelvis can be valuable as a diagnostic, screening or therapeutic procedure and this is reflected by the increasing number of articles in the recent literature.¹^–⁵ The majority of pelvic cysts that can be aspirated are ovarian in origin. However, other ‘cysts’ in the vicinity may be misinterpreted as ovarian, and aspirated accordingly. These include peritoneal inclusion cysts, paratubal cysts, colon reduplication cysts and hydrosalpinges. As has already been described, malignant cells of ovarian origin are also occasionally identified in vaginal, cervical and endometrial samples (see Chs 23, 24, 25).

Obtaining cytological material

FNA technique

Cystic lesions in the pelvis can be approached through the vagina or rectum, transabdominally, during laparoscopy and at the time of laparotomy.⁶ The transvaginal route is generally favoured as the vagina can be cleansed before puncture and is the preferred route for aspirations performed in the infertility unit, in conjunction with transvaginal ultrasonography. Transrectal aspirates are usually performed in conjunction with examination of the patient under general anaesthesia. Ovarian cysts and solid lesions, especially those that extend into the abdomen or are associated with omental lesions, can be readily aspirated via the transabdominal route. Laparoscopic visualisation and aspiration can also be safely and effectively employed in the diagnosis and management of ovarian cysts. Occasionally, pelvic cysts are found incidentally during laparotomy undertaken for other reasons. Aspiration of these cysts can provide useful diagnoses to ascertain further management. Transvaginal aspiration of ovarian cysts has been advocated as a viable alternative to surgery in patients who are high-risk surgical candidates.⁷ Lee et al. performed aspiration curettage of the inner surface of the cyst present during aspiration to facilitate cytological diagnosis.⁸

The laboratory procedure is also crucial in determining the diagnostic potential of a given sample. The fluid can be smeared directly or cytocentrifuged depending on its viscosity. It can also be processed via the liquid-based cytology (LBC) technique.⁹ It is useful to have at least two air-dried May-Grünwald Giemsa (MGG) and two wet-fixed Papanicolaou (PAP) preparations to improve the diagnostic yield as quite often only one slide contains the relevant cells. It is also advisable to prepare spare slides for immunocytochemistry.

Peritoneal washings

Peritoneal washing cytology (PWC) is a useful indicator of ovarian surface involvement and peritoneal dissemination by ovarian tumours. It may identify subclinical peritoneal spread and thus provide valuable staging and prognostic information, particularly for non-serous ovarian tumours.^10,¹¹ The role of PWC as a prognostic indicator for endometrial carcinoma is less clear, due in part to the questionable significance of identifying endometrial tumour cells in the peritoneum. Detection of metastatic carcinoma in PWC is based on the recognition of non-mesothelial cell characteristics. However, a number of conditions such as reactive mesothelial cells, endometriosis and endosalpingiosis may mimic this appearance. Cells from these conditions may have a similar presentation in PWC to that of serous borderline tumours and low-grade serous carcinoma.¹² The presence of cilia, lack of single atypical cells, prominent cytoplasmic vacuolation, marked nuclear atypia or two distinct cell populations are features favouring a benign process. Attention to these features along with close correlation with clinical history and the results of surgical pathology should help avoid errors. Additional assistance may be provided by the use of cell blocks and special stains.

Any free fluid or PWC are obtained intraoperatively, immediately after entering the abdominal cavity by using a small amount of normal saline (100–150 mL). The material is prepared in a standard manner as soon as possible after collection, in order to avoid degenerative changes, allowing sufficient material for standard and special stains including immunocytochemistry (see Ch. 3).¹³ In addition, cytological examination of peritoneal washing is applied during ‘second look’ procedures (laparotomy, laparoscopy) as a method of assessing the response to treatment.

Ovaries

Non-neoplastic cystic lesions

Prior to the cytological interpretation of ovarian FNA smears, cytopathologists should be thoroughly familiar with the aspiration route and with clinical and radiological findings, in particular, if the investigation is part of the infertility treatment.^2,³ Knowledge of the route is essential as normal cells from various sites may be inadvertently aspirated during the passage of the needle towards the ovary.¹ These contaminants include squamous epithelial cells from vaginal mucosa, columnar cells from rectal mucosa and mesothelial cells from the peritoneum.

The clinical and radiological features are extremely important in order to formulate a differential diagnosis and determine if the findings are representative of the aspirated lesion.^1,⁶ The decision to aspirate an ovarian lesion is usually determined by the radiological findings, especially ultrasonography.^6,¹⁴ FNA of cystic and solid lesions present different problems and opinions concerning its use in diagnosis and treatment are not unanimous.^2,^3,¹⁵^–¹⁷

Ultrasound can generally distinguish unilocular cysts from those that are multiloculated, which have thick septa or contain solid areas.^2,³ Unilocular cysts, especially when present in young or pregnant women, are usually benign, while multiloculated cysts could be associated with a more serious lesion. Unilocular ovarian cysts measuring <5 cm in diameter and containing <20 mL fluid are usually functional and resolve spontaneously. Those 5–10 cm in size are more likely to be symptomatic and associated with a more significant condition, including a neoplastic process, and these are more often investigated by FNA.¹⁸

In the appropriate clinical setting, if the FNA from one of these cysts is straw coloured or clear, most patients are managed conservatively. A high fluid level of unconjugated oestradiol-17β (E₂) favours a functional follicular cyst rather than a neoplastic process.¹⁶ However, certain ovarian neoplasms such as granulosa cell tumour also produce oestrogen and the measurement may therefore be of limited significance. A high CA125 level in the fluid may indicate a neoplastic process.¹⁹ If, however, the cyst recurs after aspiration or the aspirated fluid is haemorrhagic, removal may be necessary. When necrotic material or pus is aspirated, distinction between abscess and necrotic tumour may be cytologically difficult.³

The use of immunocytochemical techniques enables the distinction between functional and neoplastic cysts in most cases, as the latter are usually lined by epithelial cells.²⁰ Positivity of cells with the antibody to the α-subunit of inhibin, and to a lesser extent to the β-subunit, indicates follicular cells of a functional cyst.²¹ Positivity with BerEP4 or CA125 indicates epithelial cells and hence a neoplasm, but can include endometriotic cysts.²⁰

Non-neoplastic cystic lesions of the ovary include follicular, corpus luteal and germinal inclusion cysts. In most aspirates from benign unilocular cysts with clear fluid the specimens are usually sparsely cellular, containing lymphocytes and macrophages. It is often not possible to make a definitive diagnosis or differentiate the various types of cysts on the basis of the cytological findings alone.^2,¹⁶

Cytological findings: non-neoplastic cysts

Follicular cysts

• Watery straw-coloured fluid which may be blood stained

• Moderate cellularity

• May include numerous granulosa cells arranged singly and in tight clusters (Fig. 27.1)^2,²²

• The cells generally have round and sometimes oval nuclei, some of which have longitudinal nuclear grooves, producing a coffee bean appearance

• The nuclei have coarsely granular chromatin rendering a pepper-pot appearance and there is a small rim of distinct cytoplasm (Fig. 27.2)

• Mitotic figures may be present.

Fig. 27.1 Tightly packed clusters of follicular cells with round to oval nuclei and scanty cytoplasm. FNA of ovary (A, MGG; B, PAP).

Fig. 27.2 Follicular cells with rounded nuclei containing multiple nucleoli and coarse chromatin rendering a pepper-pot appearance. FNA of ovary (PAP).

The existence of ciliated bodies (detached ciliary tufts in fluids of ovarian cysts) indicates the presence of ciliated columnar epithelial cells in the wall of the cyst, which would exclude a follicular origin.²³

Endometriotic cysts

• Aspirates usually macroscopically haemorrhagic, brown fluid and contain numerous haemosiderin-laden macrophages (Fig. 27.5)

• In the background of degenerate blood, there is quite often cellular debris including wisps of cytoplasm admixed with degenerate nuclear material, both generally of small size, but of variable shapes

• Occasionally collagenous bodies are noted ^26,²⁷

• Intact endometrial cells are seldom seen.²² These cells are isolated or arranged in tight clusters. The cytoplasm is scanty and the nuclei are round or oval with finely granular chromatin (Fig. 27.6).