Uterine myxoid leiomyosarcoma with an underlying haematological disorder – case report and review of literature

Abstract

Uterine myxoid leiomyosarcoma is an exceptionally unusual variant of leiomyosarcoma with only 34 cases having been reported in the literature. The authors describe a case of myxoid leiomyosaroma with an underlying haematological profile that has not been described previously. A 38-year-old Caucasian woman with a known uterine fibroid discovered during pregnancy presented to the emergency department with heavy per vaginal bleeding. On examination, she had a large abdominal mass. She had a haemoglobin level of 5.2, platelets of 16 and a low white cell count. She received multiple blood and platelet transfusions, despite which her haemoglobin and platelet count levels remained low. She underwent two bone marrow biopsies, which were inconclusive. She underwent laparotomy for abdominal hysterectomy, bilateral salphingo-oohphorectomy, omentectomy and appendicectomy. Histological examination showed uterine myxoid leiomyosarcoma (International Federation of Gynaecology and Obstetrics stage IIIA). Her haematological profile improved significantly following surgical resection of the tumour, reappearing with the recurrence of the disease. The authors hence, consider that pancytopaenia in this patient was a manifestation of paraneoplastic syndrome.

Background

This case is important due to its rarity, and unusual presentation which has not been previously reported.

Case presentation

A 38-year-old Caucasian woman gravida 4, para 4 first presented postcaesarean section due to a fibroid uterus with increasing period pain and abdominal discomfort.

There was no medical history other than asthma, she underwent a traumatic emergency c-section due to unstable lie from the fibroid with her last child.

She was offered a hysterectomy however, in view of her age and the fact that she was unsure about whether her family is complete; she was booked for an elective myomectomy and hysteroscopy. She additionally received a zoladex injection prior to myomectomy.

During the hysteroscopy, a necrotic polypoid lesion was found to be projecting through the cervical os. Moreover, fronds of tissue and gelatinous mucoid material were filling the uterine cavity. Sample specimens were taken for histology and the myomectomy was abandoned. The histology of the tissue revealed necrosis and profoundly myxoid degeneration of a submucosal leiomyoma. No evidence of malignancy was seen. By this stage, the patient had decided to opt for a hysterectomy and was put on the waiting list.

Prior to her operation, she presented to the emergency department with heavy per vaginal bleeding

Investigations

Abdominal ultrasonography revealed a small area of fibroid at the fundus of uterus extending to the left adnexa where there was a complex mass measuring 9×8×9.5 cm. She went on to have a CT scan which clarified the presence of an ovarian mass, a fibroid on the left side with adherence with the left ovary.

Her haemotology results from A&E – She had a haemoglobin level of 5.2 and platelet count of 16 both of which has been previously normal. She subsequently received multiple blood and platelet transfusions, despite which her haemoglobin and platelet count levels remained low. In addition, she also had a low white cell count. She was suspected to have bone marrow dysfunction and consequently underwent two bone marrow biopsies both of which came back as inconclusive.

Treatment

After laparotomy for abdominal hysterectomy, bilateral salphingo-oohphorectomy, omentectomy and appendicectomy, she went on to have chemotherapy.

Outcome and follow-up

Histology revealed a malignant mesenchymal neoplasm, with abundant myxoid stroma, large pleomorphic multinucleated cells were present and abundant mitotic activity. On the basis of the above characteristics she was diagnosed as having uterine myxoid leiomyosarcoma (International Federation of Gynaecology and Obstetrics stage IIIA). A week later the patients haemoglobin improved to 12.9 and her platelet count came up to 76, she was subsequently discharged.

The patient went on to have a follow-up CT scan which showed multiple pulmonary nodules in both her lungs suggestive of possible metastasis, she is currently having chemotherapy with doxorubicin.

Discussion

Uterine sarcomas account for only 3% of uterine malignancies¹ and approximately one third of these will be a leiomyosarcoma¹ which principally present with irregular vaginal bleeding and pelvic or abdominal pain. Leiomyosarcoma are highly malignant tumours of the smooth muscle cells, which are usually easily differentiated from benign leiomyoma’s due to their dissimilar characteristic features: size, colour, contour and pathologically – hyercellularity, atypia and frequent mitotic figures.¹

Myxoid leiomyosarcoma of the uterus is an aggressive and exceptionally uncommon form of leiomyosarcoma which has proved to be a diagnostic challenge owing to its rarity and lack of the usual criteria for malignancy, for instance they often present with a low mitotic activity.²

King et al³ first described ‘myxoid leiomyosarcoma of the uterus’ in 1982, when they reported on six cases. The patients ranged in age from 47 to 68 and all presented with either vaginal bleeding and/or a pelvic mass. Looking through the literature – 34 cases in all, our patient fitted the usual characteristics in many aspects. First, she was 38 which is in the anticipated age range that varies from 20 to 74.^{4 5} She presented with the same symptoms of abnormal vaginal bleeding^{3 6} and an abdomino-pelvic mass^{2 3} as the other cases in the literature. The mass was large (20 cm at the greatest diameter) which falls within the range of 5 to 45 cm.^{2 3} Additionally, she received the same treatment as the majority of patients were treated with a total abdominal hysterectomy and bilateral salpingo-ophorectomy usually followed by chemotherapy; furthermore many also had a recurrence of the disease with the time of recurrence ranging from 2 months up to 10 years.^{2 3} However, this case did display high mitotic activity which is more unusual in these cases.

In our case, a further dilemma was encountered due to an underlying haematological disorder. Our patient presented with myelosuppression and on occasion’s pancytopaenia in addition to irregular bleeding and a pelvic mass, this has so far not been previously reported and as yet there is no clear reason or diagnosis for this occurrence.

Looking into the relationship of pancytopaenia and myxoid leiomyosarcoma there are few possible theories.

First, this patient could have developed disseminated intravascular coagulation (DIC), however, in this case the patient had thrombocytopenia but the clotting profile was normal, which rules out DIC as a diagnosis.

Paraneoplastic syndromes are not frequently associated with gynaecological malignancies⁷ but another possibility is malignancy resulting in a paraneoplastic haematological syndrome. This could be the case as her mylosupression was present at first presentation, subsequently resolved after surgery and then reappeared at the next presentation when progression of her disease was discovered. Three cases have been reported previously where patients presented with pancytopaenia and hypercellular bone marrow in the presence of carcinoma of the lung.⁸ It was said that pancytopaenia in patients with malignancy without obvious metastases in the bone marrow is extremely rare.⁸ Evidently the patient described in this case report had bone marrow biopsy performed twice and both came back as inconclusive. However, the cases reported in literature were associated with carcinoma of the lung. Uterine leiomyosarcoma was not known to be associated with pancytopaenia and hyperculluar bone marrow. It could also be argued that this lady had metastases to the lung from the primary tumour which could have triggered the paraneoplastic haematological syndrome.

In summary, this case has demonstrated a rare and aggressive form of uterine cancer which was complicated by an underlying haematological disorder which could demonstrate a paraneoplastic syndrome.

Learning points.

• ▶Myxoid leiomyosarcoma of the uterus is an aggressive and exceptionally uncommon form of leiomyosarcoma which has proved to be a diagnostic challenge owing to its rarity and lack of the usual criteria for malignancy.
• ▶Paraneoplastic syndromes are not frequently associated with gynaecological malignancies⁸ but could be the case as her myelosuppression was present at first presentation, subsequently resolved after surgery and then reappeared at the next presentation when progression of her disease was discovered.