Investigations by the physician include imaging (ultrasound, CAT scan, MRI) and, if possible, obtaining a tissue diagnosis by biopsy, hysteroscopy, or D&C.

Ultimately the diagnosis is established by the histologic examination of the specimen. Typically malignant lesions have >10 mitosis per high power field. In contrast a uterine leiomyoma as a benign lesion would have < 5 mitosis per high power field.

The prognosis is determined primarily by the cancer stage. Most tumours are discovered at an early stage and have a good prognosis, especially when compared to uterine carcinosarcoma. Five year survival for stage I and stage III tumours is approximately 80% and 50% respectively.

Unusual or postmenopausal bleeding may be a sign of a malignancy including uterine sarcoma and needs to be investigated. Other signs include pelvic pain, pressure, and unusual discharge. A nonpregnant uterus that enlarges quickly is suspicious. However, none of the signs are specific. Specific screening test have not been developed; a Pap smear is a screening test for cervical cancer and not designed to detect uterine sarcoma.

Uterine adenosarcomas are typically treated with a total abdominal hysterectomy and bilateral salpingoophorectomy (TAH-BSO). Ovary sparing surgery may be done in women wishing to preserve fertility.

Differential diagnosis of this condition includes the Birt-Hogg-Dubé syndrome and tuberous sclerosis. As the skin lesions are typically painful, it is also often necessary to exclude other painful tumors of the skin (including blue rubber bleb nevus, leiomyoma, eccrine spiradenoma, neuroma, dermatofibroma, angiolipoma, neurilemmoma, endometrioma, glomus tumor and granular cell tumor; the mnemonic "BLEND-AN-EGG" may be helpful). Other skin lesions that may need to be considered include cylindroma, lipoma, poroma and trichoepithelioma; these tend to be painless and have other useful distinguishing features.

The skin lesions may be difficult to diagnose clinically but a punch biopsy will usually reveal a Grenz zone separating the tumour from the overlying skin. Histological examination shows dense dermal nodules composed of elongated cells with abundant eosinophilic cytoplasm arranged in fascicles (spindle cells). The nuclei are uniform, blunt-ended and cigar-shaped with only occasional mitoses. Special stains that may be of use in the diagnosis include Masson's trichrome, Van Gieson's stain and phosphotungstic acid–haematoxylin.

The renal cell carcinomas have prominent eosinophilic nucleoli surrounded by a clear halo.

The presence of a uterine fibroid versus an adnexal tumor is made. Fibroids can be mistaken for ovarian neoplasms. An uncommon tumor which may be mistaken for a fibroid is Sarcoma botryoides. It is more common in children and adolescents. Like a fibroid, it can also protrude from the vagina and is distinguished from fibroids. While palpation used in a pelvic examination can typically identify the presence of larger fibroids, gynecologic ultrasonography (ultrasound) has evolved as the standard tool to evaluate the uterus for fibroids. Sonography will depict the fibroids as focal masses with a heterogeneous texture, which usually cause shadowing of the ultrasound beam. The location can be determined and dimensions of the lesion measured. Also, magnetic resonance imaging (MRI) can be used to define the depiction of the size and location of the fibroids within the uterus.

Imaging modalities cannot clearly distinguish between the benign uterine leiomyoma and the malignant uterine leiomyosarcoma, however, the latter is quite rare. Fast growth or unexpected growth, such as enlargement of a lesion after menopause, raise the level of suspicion that the lesion might be a sarcoma. Also, with advanced malignant lesions, there may be evidence of local invasion. A biopsy is rarely performed and if performed, is rarely diagnostic. Should there be an uncertain diagnosis after ultrasounds and MRI imaging, surgery is generally indicated.

Other imaging techniques that may be helpful specifically in the evaluation of lesions that affect the uterine cavity are hysterosalpingography or sonohysterography.

About 1 out of 1000 lesions are or become malignant, typically as a leiomyosarcoma on histology. A sign that a lesion may be malignant is growth after menopause. There is no consensus among pathologists regarding the transformation of leiomyoma into a sarcoma.

Leiomyoma is the most common benign mesenchymal tumor of esophagus and second most common benign tumor of the small bowel (with gastrointestinal stromal tumor as most common). Although leiomyoma is the most common benign esophageal tumor, malignant carcinoma is still 50 times more likely. Approximately 50% of cases are found in the jejunum, followed by the ileum in 31% of cases. Almost one half of all lesions are less than 5 centimeters.

Adenomyosis can vary widely in the extent and location of its invasion within the uterus. As a result, there are no established pathognomonic features to allow for a definitive diagnosis of adenomyosis through non-invasive imaging. Nevertheless, non-invasive imaging techniques such as transvaginal ultrasonography (TVUS) and magnetic resonance imaging (MRI) can both be used to strongly suggest the diagnosis of adenomyosis, guide treatment options, and monitor response to treatment. Indeed, TVUS and MRI are the only two practical means available to establish a pre-surgical diagnosis.

The diagnose of adenomyosis is through a pathologist microscopically examining small tissue samples of the uterus. These tissue samples can come from a uterine biopsy or directly following a hysterectomy (surgery to remove the uterus). Uterine biopsies can be obtained by either a laparoscopic procedure through the abdomen or hysteroscopy through the vagina and cervix. The diagnosis is established when the pathologist can find invading clusters of endometrial tissue within the myometrium. Several diagnostic criterion can be used, but typically they require either the endometrial tissue to have invaded greater than 2% of the myometrium, or a minimum depth of invasion such as 1–4 mm.

A widely recognised method of estimating the risk of malignant ovarian cancer based on initial workup is the "risk of malignancy index" (RMI). It is recommended that women with an RMI score over 200 should be referred to a centre with experience in ovarian cancer surgery.

The RMI is calculated as follows:

There are two methods to determine the ultrasound score and menopausal score, with the resultant RMI being called RMI 1 and RMI 2, respectively, depending on what method is used:

An RMI 2 of over 200 has been estimated to have a sensitivity of 74 to 80%, a specificity of 89 to 92% and a positive predictive value of around 80% of ovarian cancer. RMI 2 is regarded as more sensitive than RMI 1.

Mesenchymal neoplasms of the gallbladder are rare and in particular leiomyomas of the gallbladder have been rarely reported, all of them in patients with immune system disorders. Although, recently, a case was reported in absence of associated immunodeficiency at Monash Hospital in Melbourne Australia in a healthy 39-year-old woman with no symptoms.

Benign metastasizing leiomyoma is a rare condition characterized by the growth of uterine leiomyoma in the other regions especially the lungs.

Outcome of MMMTs is determined primarily by depth of invasion and stage. As with endometrial carcinomas, the prognosis is influenced by the grade and type of the adenocarcinoma, being poorest with serous differentiation. MMMTs are highly malignant; a stage I tumor has an expected five-year survival rate of 50%, while the overall five-year survival rate is less than 20%.

Staging of Uterine MMMTs is as follows:

- Stage I. Carcinoma is confined to the corpus uteri itself.

- Stage II. Carcinoma involves the corpus and the cervix.

- Stage III. Carcinoma extends outside the uterus but not outside the lesser pelvis.

- Stage IV. Carcinoma extends outside the true pelvis or involves the mucosa of the bladder or the rectum.

Cysts associated with hypothyroidism or other endocrine problems are managed by treating the underlying condition.

About 95% of ovarian cysts are benign, not cancerous.

Functional cysts and hemorrhagic ovarian cysts usually resolve spontaneously. However, the bigger an ovarian cyst is, the less likely it is to disappear on its own. Treatment may be required if cysts persist over several months, grow, or cause increasing pain.

Cysts that persist beyond two or three menstrual cycles, or occur in post-menopausal women, may indicate more serious disease and should be investigated through ultrasonography and laparoscopy, especially in cases where family members have had ovarian cancer. Such cysts may require surgical biopsy. Additionally, a blood test may be taken before surgery to check for elevated CA-125, a tumour marker, which is often found in increased levels in ovarian cancer, although it can also be elevated by other conditions resulting in a large number of false positives.

Uterine cancer resulted in about 58,000 deaths in 2010 up from 45,000 in 1990.

Uterine cancer is the fourth most common cancer in women in the UK (around 8,500 women were diagnosed with the disease in 2011), and it is the tenth most common cause of cancer death in women (around 2,000 people died in 2012).

In gross appearance, MMMTs are fleshier than adenocarcinomas, may be bulky and polypoid, and sometimes protrude through the cervical os. On histology, the tumors consist of adenocarcinoma (endometrioid, serous or clear cell) mixed with the malignant mesenchymal (sarcoma) elements; alternatively, the tumor may contain two distinct and separate epithelial and mesenchymal components. Sarcomatous components may also mimic extrauterine tissues (e.g., striated muscle, cartilage, adipose tissue, and bone). Metastases usually contain only epithelial components.

Intravenous leiomyomatosis is a rare condition seen exclusively in women in which leiomyomata, benign smooth muscle tumors, are found in veins. The masses are benign-appearing but can spread throughout the venous system leaving the uterus and even cause death when growing into the heart from the IVC. While the possibility that these arose de novo from the smooth muscle in the blood vessel wall was considered, chromosomal analysis suggests a uterine origin. Intravenous leiomyomata are usually but not always associated with uterine fibroids, and tend to recur.

This condition is related to benign metastasizing leiomyoma, in which the masses appear in more distant locations such as the lung and lymph nodes.

The exact incidence of maternal mortality related to placenta accreta and its complications is unknown, but has been reported to be as high as 6-7% in case series and surveys.

The diagnosis is made in asymptomatic pregnant women by obstetric ultrasonography. On pelvic examination a unilateral adnexal mass may be found. Typical symptoms are abdominal pain and, to a lesser degree, vaginal bleeding during pregnancy. Patients may present with hypovolemia or be in circulatory shock because of internal bleeding.

Ideally, ultrasound will show the location of the gestational sac in the ovary, while the uterine cavity is "empty", and if there is internal bleeding, it can be identified. Because of the proximity of the tube, the sonographic distinction between a tubal and an ovarian pregnancy may be difficult. Serial hCG levels generally show not the normal progressive rise.

In a series of 12 patients the mean gestation age was 45 days.

Histologically, the diagnosis has been made by Spiegelberg criteria on the surgical specimen of the removed ovary and tube. However, the tube and ovary are not usually removed as sonography allows for earlier diagnosis and surgeons strive to preserve the ovary. Prior to the introduction of Spiegelberg's criteria in 1878, the existence of ovarian pregnancy was in doubt; his criteria helped to identify the ovarian pregnancy from other ectopics:

- The gestational sac is located in the region of the ovary.

- The gestational sac is attached to the uterus by the ovarian ligament.

- Ovarian tissue is histologically proven in the wall of the gestational sac.

- The oviduct on the affected side is intact (this criterion, however, holds not true for a longer ongoing ovarian pregnancy).

An ovarian pregnancy can be mistaken for a tubal pregnancy or a hemorrhagic ovarian cyst or corpus luteum prior to surgery. Sometimes, only the presence of trophoblastic tissue during the histologic examination of material of a bleeding ovarian cyst shows that an ovarian pregnancy was the cause of the bleeding.

Surgery, with as wide a margin of removal as possible, has generally been the most effective and preferred way to attack LMS. If surgical margins are narrow or not clear of tumor, however, or in some situations where tumor cells were left behind, chemotherapy or radiation has been shown to give a clear survival benefit. While LMS tends to be resistant to radiation and chemotherapy, each case is different and results can vary widely.

LMS of uterine origin do frequently, but not always respond to hormonal treatments.

The terms uterine cancer and womb cancer may refer to any of several different types of cancer which occur in the uterus, namely:

- Endometrial cancer:

- Cervical cancer arises from the transformation zone of the cervix, the lower portion of the uterus and connects to the upper aspect of the vagina.

- Uterine sarcomas: sarcomas of the myometrium, or muscular layer of the uterus, are most commonly leiomyosarcomas.

- Gestational trophoblastic disease relates to neoplastic processes originating from tissue of a pregnancy that often is located in the uterus.

To remove the tumor from the body, a myomectomy or hysterectomy is often required.

A transvaginal ultrasound can reveal the condition.

Helpful techniques to investigate the uterine structure are transvaginal ultrasonography and sonohysterography, hysterosalpingography, MRI, and hysteroscopy. More recently 3-D ultrasonography has been advocated as an excellent non-invasive method to delineate the condition.