[P-03] Primary appendiceal leiomyosarcoma presenting as an acute appendicitis: a case report

Alexis Leo B. Clapis1, Emelisa G. Almocera1 and Annette L. Salillas1,2

  1. Department of Pathology, Governor Celestino Gallares Memorial Hospital, Tagbilaran City, Bohol, Philippines
  2. Matias H. Aznar Memorial College of Medicine, Cebu City, Cebu, Philippines

 

Background: Tumours primarily arising from the appendix are not common, comprising only 0.9% - 1.4% of all documented appendectomies. Among all appendiceal neoplasms, majority of cases are of well-differentiated neuroendocrine tumours. Appendiceal leiomyosarcomas are rare with only a few cases reported. Thus, diagnosis and management of this tumour is based on the behaviour of leiomyosarcoma of the colon.

Case Presentation: A 60-year-old man presented with persistent right lower quadrant abdominal pain radiating to the epigastric area for a duration of one week associated with loss of appetite. The right hemicolectomy specimen showed an irregular lobulated, tan-brown, firm appendiceal mass, measuring 8 x 7.5 x 5 cm. Cut section revealed a variegated solid surface with haemorrhagic and necrotic foci. Microscopy showed highly cellular tumour composed of spindle-shaped neoplastic cells arranged in fascicular and whorling patterns. The tumour cells have ovoid to elongate hyperchromatic nuclei, indistinct nucleoli and scant eosinophilic cytoplasm. Necrosis, haemorrhage and brisk mitotic activity were also evident. Immunohistochemical staining showed strong reactivities to SMA and desmin and negative stainings for DOG1, CD117, S-100 and pancytokeratin.

Discussion and Conclusion: Appendiceal neoplasms are uncommon, even more so for mesenchymal malignancies, with sarcomas comprising only < 1% of all appendiceal tumours. Diagnostic evaluation is through light microscopy and immunohistochemistry. The mainstay management, as of any soft tissue sarcoma, is surgical excision and an en bloc excision of contiguously affected viscera with tumour-negative margins. Having only a few cases documented worldwide; more data are required to better understand this rare tumour.