Intravenous leiomyomatosis
Synonyms and keywords: Nesidioblastoma, IVLM

# Overview
Intravenous leiomyomatosis is also refered as IVL. Intravenous leiomyomatosis is characterized by the extension into venous channels of histologically benign smooth muscle tumor arising from either the wall of a vessel or from a uterine leiomyoma. The etiology of intravenous leiomyomatosis is unclear. Intravenous leiomyomatosis must be differentiated from other diseases such as renal malignancies and sarcomas. The median age is 45 years, with patients age ranging from 26 to 70 years old. Only females may develop intravenous leiomyomatosis. Findings on CT scan diagnostic of intravenous leiomyomatosis include an irregular mass exhibiting heterogeneous enhancement with extension into adjacent veins. Findings on an ultrasound imaging diagnostic of intravenous Leiomyomatosis include a vascularized thrombi within the pelvic veins and Inferior vena  cava. Findings on MRI diagnostic of intravenous leiomyomatosis include a leiomyomatous lesion or a distorted uterus with projections into vasculature. Surgery is the mainstay of therapy for intravenous leiomyomatosis. It can grow into lymphatics /veins.

# Historical Perspective
- Intravenous leiomyomatosis first described in 1896 by German Pathologist Birch-Hirschfeld.
- First case of leiomyo-matosis of pelvic origin with intravascular extension to cardiac cavities was described in 1907 in Germany by Durck and Hormann.

# Classification
- There is no established system for the classification of intravenous leiomyomatosis.

# Pathophysiology
- Intravenous leiomyomatosis is characterized by the extension into venous channels of histologically benign smooth muscle tumors arising from either the wall of a vessel or from a uterine leiomyoma.
- Approximately 40% of leiomyomata have cytogenetic abnormalities.
- They are benign tumors of uterus that extend to venous system but do not invade the surrounding tissues. 
- They contains receptors responsive to estrogen and progesterone and hence response to these hormones. 
- It is also referred as quasi-malignant behavior due to its speedy spreading behavior.
- On microscopy it is seen as benign, well-differentiated tumor with smooth muscle cell growing within veins as worm-like projections.
- Tumor cells shows bizarre nuclear morphology with hyperchromatic multilobated nuclei.
- The mitotic activity is low, with mitotic index of less than 1 per 50 high-power fields.

# Causes
- The etiology of intravenous leiomyomatosis is unclear.

# Differentiating Intravenous Leiomyomatosis from other Diseases
- Intravenous leiomyomatosis must be differentiated from other conditions such as intravenous thrombus, leiomyosarcoma, right atrial myxoma and thrombosis of carcinomas, for example, renal cell carcinoma, hepatocellular carcinoma, and adrenocortical carcinoma.
- For more information on intravenous leiomyomatosis differential diagnosis, please click here.

# Epidemiology and Demographics
- There is no available data on the exact incidence of intravenous leiomyomatosis.
- The median age at the time of diagnosis  of IVL is 45 years, with patients age ranging from 26 to 70 years old. 
- Female are exclusively  affected with intravenous leiomyomatosis.
- Intravenous leiomyomatosis is seen more commonly in white females.

# Risk Factors
- Common risk factors in the development of intravenous leiomyomatosis are age, cytogenetic abnormalities , and prior history of uterine leiomyoma, and/or hysterectomy.

# Screening
- There is insufficient evidence to recommend routine screening for intravenous leiomyomatosis.

# Natural History, Complications and Prognosis
- If left untreated, patients with intravenous leiomyomatosis may progress to develop congestive heart failure, venous obstruction, and sudden death.
- Other possible complications of intravenous leiomyomatosis include tumor recurrence, and metastasis.
- Prognosis is generally good.

# Diagnosis

## Diagnostic Criteria
- There is no specific diagnostic Criteria for intravenous leiomyomatosis.
- Diagnosis may be challenging. However, a history of  A history of hysterectomy or the presence of uterine leiomyomas may be helpful.

## History and Symptoms
- Patients may be asymptomatic or have symptoms related to uterine leiomyomas.
- Symptoms related to uterine leiomyoma may include abdominal pain, abnormal uterine bleeding, and abdominal distension.
- Symptoms of intravenous Leiomyomatosis due to extension to great veins or invoving the heart may include dyspnoea, loss of consciousness, lower extremity edema, chest pain, abdominal pain, and fatigue.

## Physical Examination
- Patients with  intravenous Leiomyomatosis usually depends on location and extension of the tumor which may include jugular venous distention, increased pulse rate, shifting dullness in abdominal exam suggestive of ascites, and lower extremity edema.

## Laboratory Findings
- There are no specific laboratory findings associated with intravenous Leiomyomatosis.

## Electrocardiogram
- There are no ECG findings associated with intravenous Leiomyomatosis.

## X-ray
- There are no x-ray findings associated with intravenous Leiomyomatosis.

## Echocardiography or Ultrasound
- Echocardiography/ultrasound may be helpful in the diagnosis of intravenous Leiomyomatosis.
- Findings on an ultrasound imaging diagnostic of intravenous Leiomyomatosis include a vascularized thrombi within the pelvic veins and IVC.
- Echocardiography may show findings consistent with right atrial involvement of the tumor.
- Possible findings of IVL on echocardiography include hyperechoic elongated mobile mass extending from the inferior vena cava and an irregular lesion in the right atrium and sometimes with protrusion into the right ventricle.

## CT scan
- Pelvic CT scan may be helpful in the diagnosis of intravenous leiomyomatosis.
- Findings on CT scan diagnostic of intravenous leiomyomatosis include an irregular mass exhibiting heterogeneous enhancement with extension into adjacent veins.

## MRI
- Pelvic MRI may be helpful in the diagnosis of intravenous leiomyomatosis.
- Findings on MRI diagnostic of intravenous leiomyomatosis include a leiomyomatous lesion or a distorted uterus with projections into vasculature.
- The tumor usually shows low signal intensity similar to that of smooth muscle on T2-weighted images and low to intermediate signal intensity on T1-weighted images.
- The appearance of the lesion varies according to its smooth muscle cell and fibrous tissue content.

## Other Imaging Findings
- There are no other imaging findings associated with intravenous leiomyomatosis.

## Other Diagnostic Studies
- There are no other diagnostic studies associated with intravenous leiomyomatosis.

# Treatment

## Medical Therapy
- There is no treatment for intravenous leiomyomatosis.

## Surgery
- Surgery is the treatment of choice, and complete removal of the tumor is mandatory.
- Recurrences may occur up to 15 years after the primary occurrence in patients with Incomplete resection of the tumor.
- Bilateral oophorectomy causes shutdown of hormonal stimulation hence helps preventing recurrence.
- Surgical removal can be done in single or staged procedures.

## Primary Prevention
- There are no primary preventive measures available for IVL.

## Secondary Prevention
- There are no secondary preventive measures available for IVL.