LIPOLEIOMYOMA OF BROAD LIGAMENT: A CASE REPORT

1. LIPOLEIOMYOMA OF BROAD LIGAMENT: A CASE REPORT NUNZIA SCIBETTA - LORENZO MARASA’ Department of Pathology, A.R.N.A.S. Civico, Palermo

2. INTRODUCTION • The lipoleiomyoma are rare, benign, mixed, mesen-chymal tumors composed of adipose and smooth muscle cells. They usually arise from the uterus, with the extrauterine tumors (myolipoma) being extremely rare. • The broad ligament which includes the mesosalpinx and meso-varium contains a variety of structures and tissue from which neoplasm can arise, including remnants associated with minor disorders of embryonic development of mullerian duct origin, such hydatidis of Morgagni and accessory fallopian tubes. • We present a case of an lipoleiomyoma of broad ligament arised from the wall of an accessory fallopian tube, because of its rarity and its uncommon site of occurrence.

3. METHODS • A 75-year old woman was subjected to laparatomy for intestinal subocclusion. • A nodular mass of right mesosalpinx was excised. The specimen was fixed in 10% buffered formalin, embed-ded in paraffin and stained with H&E, PAS, and tricrome stain. • Immunohistochemistry was performed using antibodies directed against vimentin, desmin, smooth muscle-specific actin, S100.

4. RESULTS • Grossly the lesion was an encapsulated grey-yellowish nodule, 2,5 cm in greatest diameter. • Histologically, the tumor consisted of approximately two thirds mature adipose tissue and one third smooth muscle; the latter was regularly interspersed with the adipose tissue. • The smooth muscle bundles were disposed in short interweaving fascicles and have deeply acidophilic fibrillary cytoplasm, elongated, oval, bland nuclei, no mitoses. • The impression of myogenic differentiation was supported by fuchsinophilic staining of the myofibrils with the tricrome stain and positive staining reactions with antibodies directed against both smooth muscle actin and desmin. • Floret cells and lipoblast are not seen in the adipose tissue entirely mature, nor are medium calibre thick-walled blood vessels as seen in angiomyolipoma. • Periferically the lesion showed a small lumen lineated with cilindrical, ciliated cells, referable to accessory fallopian tube.

5. 1 2 1 . The tumor is well circumscribed and the adipose tissue and smooth muscle are irregularly intermingled 2 . The smooth muscle component is cytologically bland; there is no aty-pia of the adipocytes 3 . Small lumen lineated with cilin-drical, ciliated cells, referable to ac-cessory fallopian tube 3 2

6. IMMUNOHISTOCHEMICAL EXAMINATION Positive immunostaining for smooth muscle actin is seen in the spindle cells Positive immunostaining for EMA is seen in the ciliated cells

7. CONCLUSIONS • The case reported is a benign lesion in which there are both mature smooth muscle and adipose tissue com-ponents. The differential diagnoses include splindle-cell lipoma and hamartoma. • We believe this is not a leiomyoma with fatty change, because of the regular distribution of adipose tissue throughout the lesion, suggesting that fat is an integral part of the lesion. Medium-sized arteries with thick muscular walls such as those seen in angiomyolipoma were not seen and militate against a hamartoma. Splindle cell lipoma does not have smooth muscle differentiation.

8. MAIN REFERENCES • Nuovo M., Nuovo G., Smith D., Lewis S. : Benign Mesen-chy-moma of the Round Ligament. A report of two cases with im-munohistochemistry. Am J Clin Pathol 93 : 421-4; 1990 • Meis J.M., Enzinger F.M. Myolipoma of Soft Tissue. Am J Surg Pathol 15 (2) : 121-125; 1991