The mainstays of investigations for the evaluation of soft-tissue tumors are ultrasonography and MRI . MRI plays a vital role in the investigation of these lesions because of its accuracy in localizing the tumors and also in assessing the extent of the tumors and their degree of invasion. MRI is thus the primary investigative method to evaluate soft-tissue sarcomas.
Most musculoskeletal tumors are palpable. Obtaining initial tissue diagnosis and planning their surgical excision is therefore not unduly challenging. In some cases, where a recurrence is suspected or the primary tumor is impalpable, a method of radiological evaluation on the day of the surgery is useful to plan the incision site and successful treatment.
Pre-operative fine-wire localization has traditionally been the most popular method in localization of impalpable tumors, especially in the case of breast lesions  and impalpable soft-tissue tumors , and also in localization of intrathoracic lung lesions . However, this process involves inconvenience to the patient because of the pain and discomfort involved, and to the hospital team in terms of time consumption and organization . This method is also associated with the risk of dislodgement of the wire during preparation and surgical positioning, which results in failed excision and potential tumor seeding along the needle track . Thus, a non-invasive method of localization is preferred in the treatment of impalpable lesions.
High-resolution ultrasonography is a successful method of analyzing small tumors, including recurrences in soft tissue and subcutaneous planes . Because of the portable nature of the ultrasonography machines, they can be used intraoperatively to identify and evaluate the suspected lesions.
Fornage et al.  studied this method for intraoperative localization of breast lumps in 26 patients. In addition, they also used this technique to confirm these lumps by scanning the specimens after removal. They reported successful localization and confirmation in all of their patients. Confirmation of the excision by scanning was useful because two of the specimens were not found during the first excision, and they proceeded to further excision and confirmation in the same setting. They concluded that this method is effective and successful, and reduces inconvenience to the surgical team and the patient.
In addition, high-resolution ultrasonography has been successful in assisting with accurate localization and collection of tissue specimens to aid with diagnosis . We have also used portable ultrasonography regularly to target core needle biopsies of sarcomas, with similar success, eliminating the need in some cases for radiological referral to obtain tissue diagnosis and subsequent treatment for the patient.
We believe that portable ultrasonography machines are a valuable adjunct to perioperative localization of impalpable soft-tissue tumors, and this use could be transferred to enable accurate targeting of soft-tissue tumors in the outpatient department. This can alleviate the need for radiologist presence in obtaining tissue diagnosis and at the time of surgery. We have been unable to find any other studies of portable ultrasonography use in the intraoperative evaluation of soft-tissue tumors as an aid to planning surgical approach, despite an extensive literature search using PubMed and MEDLINE.
Studies have been carried out to evaluate the efficacy of portable ultrasonography in detecting soft-tissue foreign bodies, which have rated the overall sensitivity as 89% and specificity as 93%s . In spite of the high sensitivity and specificity rates documented, there is evidence that in the hands of inexperienced operators, the use of portable ultrasonography is neither sensitive nor specific .
In our study group, we had an anesthetist with expertise in using the portable ultrasonography to guide us through the tumor localization process. Although use of ultrasonography is associated with a learning curve, we believe that with appropriate training, guidance from an experienced anesthetist available at the time of surgery, and regular use, portable ultrasonography machines can be a valuable adjunct in the intraoperative localization of impalpable tumors and also in obtaining tissue samples for diagnosis in the outpatient department.