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Low‐grade Fibromyxoid Sarcoma of the Sigmoid Presenting as Uterine Fibroid
Author(s) -
MENDOZA ALEJANDRO S.,
Peng ShiKaung,
French Samuel W.
Publication year - 2016
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.30.1_supplement.lb438
Subject(s) - medicine , sigmoid colon , sarcoma , biopsy , pelvis , abdomen , radiology , pathology , surgery , rectum
BACKGROUND Low‐grade fibromyxoid sarcoma(LGFMS) is a rare soft tissue tumor with a slight male predominance. The tumor has a tendency to arise from deep soft tissue of the trunk and lower extremities. Rare cases are reported to arise from the mediastinal and retroperitoneal areas. Its deceptively bland histologic appearance makes this tumor difficult to diagnose. We report a case of low‐grade fibromyxoid sarcoma presenting as uterine fibroid. CASE REPORT The patient is a 48‐year‐old obese female with a history of hypertension and menometrorrhagia who presented complaining of persistent lower abdominal pain and vaginal bleeding. A transvaginal ultrasound revealed an 8.7 cm uterine fibroid and MRI of the pelvis revealed a 10.6 × 6.9 × 8.1 cm lobulated mass within the mid pelvis. The patient was taken to the operating room for a total abdominal hysterectomy with bilateral salpingo‐oophorectomy for a mass of presumed gynecologic origin. Intraoperatively, a large 12 cm mass located in the pelvis was seen to be arising from the sigmoid colon. A shave biopsy was obtained, abdomen closed, and further staging of the colonic mass ensued. Further tests were negative of metastatic disease. Patient consequently underwent emergent sigmoidectomy due to bowel obstruction. Histologically, the tumor showed a swirling whorled growth pattern with alternating fibrous and myxoid areas. The myxoid area had a low to moderate cellularity composed of bland spindle cells with scant cytoplasm, uniform elongated nuclei, and small inconspicuous nucleoli. The tumor cells stained negative for most muscle, neural and mesenchymal stains but positive for CD99, BCL2 and MUC4 stains. CONCLUSION LGFMS has a deceptively bland histologic appearance making this tumor difficult to diagnose. CD99 and BCL2 stains will yield 90% positivity. MUC4 stain is highly specific and 100% sensitive for low grade fibromyxoid sarcoma. Molecular study will be 90% positive for t(7;16)(q32–34;p11) FUS‐CREB3L2 fusion gene. Support or Funding Information We declare no benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article.