2 Cases of a Benign Pulmonary Metastasizing Leiomyoma

A benign pulmonary metastasizing leiomyoma is a recognized clinical entity that has been infrequently reported in the medical literature. We report two cases of a benign pulmonary metastasizing leiomyoma. A 35-year-old woman who underwent myomectomy and a cesarean section approximately 6 years earlier visited our hospital for further evaluation of incidentally revealed multiple lung nodules. A diagnostic percutaneuous biopsy was performed. Finally she was diagnosed with a benign metastasizing leiomyoma. The patient then received LH-RH and has been followed up since. The other 44-year-old woman presented after an initial radiology evaluation revealed the presence of multiple, small-sized lung nodules. She underwent a right middle lung wedge resection to confirm the diagnosis. Finally she diagnosed with a benign metastasizing leiomyoma. The multiple lung nodules have been followed up closely.

Key Words: Benign Metastasizing Leiomyoma; Lung Nodules; Myomectomy; Hysterectomy

Address for correspondence: Kwang Ho In, M.D., Ph.D.

Division of Respiratory and Critical Care Medicine, Depart- ment of Internal Medicine, Korea University College of Medicine, 126-1, 5-ga, Anam-dong, Sungbook-gu, Seoul 136-705, Korea

Phone: 82-2-920-5316, Fax: 82-2-929-2045 E-mail: [email protected]

Received: Jun. 28, 2005 Accepted: Aug. 22, 2005

This work was published in the Journal of Lung Diseases Volume 2, Number 1, Page 19∼23.

Introduction

A benign metastasizing leiomyoma (BML) is a rare condition that is characterized by the benign histological appearance and presence of well-differentiated smooth muscle cells in the lesions. This condition may present in women of any age with uterine leiomyoma. The pa- tients are usually asymptomatic with the pulmonary le- sions generally being discovered incidentally. The lung is the most common site of involvement

.

We report two cases of a benign metastasizing leio- myoma in women with a history of uterine leiomyoma.

Case Report Case 1

A 35-year-old woman presented after the initial radi-

ology evaluation incidentally revealed the presence of

multiple lung nodules. She complained of cough and

whitish sputum but she denied dyspnea, hemoptysis or

fever. There was no history of malignancy. Her medical

history included only myomectomy and a cesarean sec-

tion performed approximately 6 years earlier. No abnor-

mal sounds were present upon auscultation of the

chest. A chest X-ray revealed two lung nodules (Figure

1). A chest CT was subsequently performed, which

demonstrated two nodules, one 0.8 cm diameter nodule

in the right middle lobe and the another 1.0 cm diame-

ter nodule in the left upper lobe (Figure 2). There was

no mediastinal lymphadenopathy. A diagnostic trans-

thoracic needle biopsy was performed and she was fi-

nally diagnosed with a benign metastasizing leiomyoma

(Figure 3). The patient then received LH-RH and has

been followed up since.

Figure 1. Chest radiograph shows multiple lung nod- ules.

Figure 2. Chest CT shows two round, well-defined and poorly enhanced nodules.

Figure 3. (A) Microscopic examination of a percutaneous needle biopsy specimen of the lung nodule shows intersecting

bundles of spindle-shaped cells, which are strongly-positive for (B) smooth muscle actin immunohistochemical stain,

and they highly express both (D) estrogen and (E) progesterone. However, the tumor cells are negative for (C) C-kit

(CD 117) immunohistochemical stain (A, H&E stain, ×400).

Figure 4. Chest radiograph shows multiple, round lung nodules.

Figure 5. Chest CT reveals multiple nodules ranging in diameter from a few milli- meters to 2 cm.

Case 2

A 44-year-old woman presented after an initial radiol- ogy evaluation incidentally revealed the presence of multiple, small-sized lung nodules. The patient denied dyspnea, cough, sputum production, hemoptysis or fe- ver and there was no history of a malignancy. Her sig- nificant medical history included only a total hyster- ectomy performed approximately 10 years earlier. No crackles nor rales were present upon auscultation of the chest. A chest X-ray showed multiple lung nodules (Figure 4). CT of the chest was subsequently performed, which demonstrated multiple lung nodules ranging in size from a few millimeters to 2 cm in diameter (Figure 5). However, there was no mediastinal lymphadenop- athy, pleural effusion or calcification. A diagnostic per-

cutaneous biopsy was performed. The lesions were mainly suspected of being a benign spindle cell tumor.

She underwent a right middle lung wedge resection to confirm the diagnosis and was finally diagnosed with a benign metastasizing leiomyoma (Figure 6). The pa- tient did not receive any further treatment, and the mul- tiple lung nodules have been followed up closely.

Discussion

Leiomyomas are the most common benign uterine

neoplasms of the myometrium. However, a BML is a

rare condition characterized by the occurrence of be-

nign smooth muscle tumors. These lesions are most of-

ten located in the lung in association with uterine

leiomyomatosis. Other sites of involvement include the

pelvic lymph nodes, skull base, spine, brain, heart, ret-

Figure 6. (A) The resected nodule is clearly demarcated from thesurrounding lung tissue. (B) It shows thetypical features of a leiomyoma with no findings suggestive of malignant potential such as coagulative necrosis, increased mitotic activity or significant atypia. (C) The low cuboidal metaplastic bronchiolar epithelia are invaginated and entrapped between the fascicles of the smooth muscle (H&E stain, A, ×40, B, ×200, C, ×200).

roperitoneum etc

. This condition may present in women of any age with uterine leiomyoma. Abramson et al

reported that nodules can be observed 3 months to 20 years after a hysterectomy or myomectomy. The clinical course is typically indolent, with the patient mortality commonly occurring from an unrelated dis- ease process. There is little correlation between the ex- tent of the disease and the respiratory symptoms

. The etiology of metastasizing leiomyomas includes the presence of metastatic disease from an existing leio- myoma and the presence of multicentric leiomyomatous growths

. Estrogen and progesterone receptors have been identified on the lung lesions, which has led to treatment options based on hormonal therapy through surgery or medical oophorectomy. However, surgery or hormonal therapy may not always be indicated. The ef- fects of natural hormonal changes such as pregnancy and menopause have also been associated with the re- gression of these lesions

.

Almost all patients reported thus far were Caucasians.

We report two Oriental patients. One woman had my- omectomy performed before the discovery of her pul- monary lesions, and the other underwent a total hyster- ectomy and myomectomy. Both experienced surgical trauma such as a hysterectomy or myomectomy. These cases further support the higher risk of a benign meta- stasizing leiomyoma after a surgical procedure on the uterus. In our cases, one woman was closely observed

without any management for 5 years. Despite the nu- merous lung nodules, she has rarely complained of res- piratory symptoms such as dyspnea, cough, sputum production and hemoptysis. She has remained stable without any evidence of aggravation.

To our knowledge, there are only 2 other cases re- ported in Korea. Both underwent a hysterectomy due to a benign uterine leiomyoma. After being diagnosed with abenign metastasizing leiomyoma, one was ob- served and the other was treated with a wedge resection of all the lung nodules

.

In conclusion, benign metastasizing leiomyoma is a rare entity that usually affects women after a hyster- ectomy or myomectomy for leiomyoma. The lesions are usually discovered incidentally and have an indolent clinical course. The lung is the most common site of metastatic involvement. Therefore, benign metastasizing leiomyoma should be considered for any asymptomatic patient presenting with multiple pulmonary nodules and a history of uterine leiomyoma.

References

1. Giove S, Scappaticci E, Baldi S, Ricci C, Minetto E.

Benign metastasizing leiomyoma of the uterus: case report. Minerva Med 1984;75:1819-21.

2. Abramson S, Gilkeson RC. Multiple pulmonary nodules in an asymptomatic patient. Chest 1999;116:245-7.

3. Abramson S, Gilkeson RC, Goldstein JD, Woodard PK,

716.

6. Tietze L, Gunther K, Horbe A, Pawlik C, Klosterhalfen B, Handt S, et al. Benign metastasizing leiomyoma: a

JB, et al. A case of benign metastasizing leiomyoma in

the lung. Tuberc Respir Dis 2000;49:231-6.