title: Alveolar soft part sarcoma 'revisited':  clinicopathological review of 47 cases from a tertiary cancer referral centre, including immunohistochemical expression of TFE3 in 22 cases and 21 other tumours.
abstract: BACKGROUND
  Alveolar soft part sarcoma accounts for 0.5-1.0% of soft tissue sarcomas in the United States. At our Hospital, it constitutes 1.8% of the newly diagnosed soft tissue sarcomas. Lately, TFE3 has been found to be a useful immunohistochemical marker for diagnosing this sarcoma.
  
  
  METHODS
  We reviewed 47 cases of alveolar soft part sarcoma that were either treated at Tata Memorial Hospital, Mumbai, India, or were referred in consultation from various parts of India. TFE3 immunohistochemical staining was performed on 22 alveolar soft part sarcomas and on 21 other tumours.
  
  
  RESULTS
  Unlike most other large series, 58% of patients were males and 40% were females. The ages ranged from 2 to 54 years (median 24 years). Tumours were located in the deep soft tissues of lower extremities (54%), upper extremities (13%), head and neck (11%), retroperitoneum (10%), chest wall (6%), pelvis (4%), and were positive for TFE3 (20/22, 91%), desmin (3/18, 16%), myoglobin (1/6, 17%) and smooth muscle actin (1/9, 11%). TFE3 was positive in tumour controls that comprised paragangliomas (3/4), translocation related renal cell carcinoma (1/1), adrenocortical carcinoma (1/3) and granular cell tumour (1/3). Treatment consisted of primary surgical excision, metastatectomy, chemotherapy and radiotherapy. Seven tumours (24%) recurred locally and 21 of 29 (72%) metastasised, mainly to the lungs. Follow-up information (5-108 months, median 27.5 months) was available for 22 patients. No patients died in the relatively short follow-up period.
  
  
  CONCLUSIONS
  TFE3 is a useful immunohistochemical marker for diagnosis of an alveolar soft part sarcoma. Awareness of other tumours expressing TFE3 is vital. Alveolar soft part sarcoma has a high metastasis rate but relatively good short-term survival. Surgical excision with follow-up forms the present management.
authors.affiliation: Department of Pathology, Tata Memorial Hospital, Parel, Mumbai, India. rekhi.bharat@gmail.com
authors.forename: Bharat
authors.initials: B
authors.lastname: Rekhi
authors.forename: Abhijeet
authors.initials: A
authors.lastname: Ingle
authors.forename: Manish
authors.initials: M
authors.lastname: Agarwal
authors.forename: Ajay
authors.initials: A
authors.lastname: Puri
authors.forename: Siddharth
authors.initials: S
authors.lastname: Laskar
authors.forename: Nirmala A
authors.initials: NA
authors.lastname: Jambhekar
mesh_terms: D000293:Adolescent; D000328:Adult; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000378:metabolism; D002648:Child; D003131:Combined Modality Therapy; D005260:Female; D006784:Hospitals, Teaching; D006801:Humans; D007150:Immunohistochemistry; D007194:India / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D018234:Sarcoma, Alveolar Soft Part / Q000378:metabolism / Q000401:mortality / Q000556:secondary* / Q000628:therapy; D012983:Soft Tissue Neoplasms / Q000378:metabolism / Q000401:mortality / Q000473:pathology* / Q000628:therapy; D015996:Survival Rate; D055815:Young Adult
chemical_list: D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D014408:Biomarkers, Tumor; C069203:TFE3 protein, human