Treating Clear Cell Hidradenoma Of The Dorsal Medial Forefoot
- Volume 25 - Issue 4 - April 2012
- 8213 reads
- 0 comments
The MRI findings from 2008 revealed moderate to severe hallux valgus deformity and cystic changes to the first MPJ. Adjacent to the medial aspect of the first metatarsal neck and below the site of clinically palpable abnormality, there was a T1 hypointense and T2 hyperintense soft tissue mass with multiple internal septations. It measured 1.5 cm x 1.8 cm x 1.0 cm in AP, transverse and sagittal dimensions. There was early intense enhancement of the lesion with increased vascularity in the adjacent muscular fascial planes. The enhancement persisted on delayed scan and the findings were due to a likely acquired hemangioma or a venous malformation.
In 2011, there was a follow-up MRI of the left foot with the field of view extending from the ankle through the toes. Images include axial T1, axial T2 fat-saturated, coronal T1, coronal T2 fat-saturated, sagittal T1 and sagittal T2 fat-saturated sequences without intravenous or intra-articular gadolinium. The use of intravenous or intra-articular gadolinium could not occur due to an elevated glomerular filtration rate. Physicians placed a vitamin E marker at the region of a palpable mass.
These MRI findings include an increase in the size of the soft tissue mass at the medial aspect of the first metatarsal neck/shaft to 2.5 x 1.6 x 2.5 cm. The lesion was hypo-intense on T1 and hyper-intense on T2 with internal septations. The underlying cortex appeared normal and an effusion at the first MPJ was present. Again, these impressions favored hemangioma or vascular malformation. The physician discussed the findings with the patient and scheduled surgery for excision of the mass. We also discussed risks and possible complications.
Preoperative labs were within normal limits. At initial presentation, plain film radiographs showed a moderate to severe increase in the first intermetatarsal angle with cystic changes at the first metatarsal head. The mass was not radiographically visible initially and there was no cortical involvement appreciated. However, in 2011, the mass was clearly visible on plain film as a radiopaque soft tissue mass, just proximally and medially to the first MPJ, and dorsally to the first metatarsal shaft. Again, no cortical involvement was present.
What You Should Know About The Operative Course
Before excising the mass, the surgeon ensured supine positioning of the patient under monitored anesthesia care and administered a left posterior tibial block (20 mL of 0.5% Marcaine plain). Following standard surgical preparation and draping, the surgeon made an approximately 5 cm slightly curvilinear incision beginning at the dorsal medial aspect of the forefoot, and progressing just proximally to the first MPJ to encompass the mass. The surgeon extended the incision down to the subcutaneous tissue and ligated all vessels within the mass.
The mass appeared to have both vascular and connective tissue components. Using blunt dissection and an iris scissor, the surgeon freed the mass along the dermis. Upon dissection, the surgeon located a vascular supply to the mass plantarly and inferior to the extensor hallucis longus tendon. The surgeon tied off the vascular supply using a 3-0 Vicryl reel. The surgeon mobilized all surrounding structures from the surgical site and sent the specimen to pathology.