Imaging findings of recurrent tumors after orbital exenteration and free flap reconstruction.

PURPOSE: Tumors that recur following orbital exenteration may not be evident on clinical examination, highlighting the need for imaging surveillance. The goal of this study was to report the imaging characteristics of recurrent tumors following orbital exenteration and free flap reconstruction. METHODS: The authors retrospectively reviewed the records of 48 patients who underwent orbital exenteration for the treatment of orbital malignancy and identified 17 recurrent tumors in 17 patients. The lesions were assessed for the presence of a soft tissue mass, imaging characteristics, and fluorodeoxyglucose avidity. RESULTS: The recurrent tumors were detected 1 month to 6 years 10 months (median, 1 year 3 month) after orbital exenteration. On both CT and MRI, all 17 lesions were soft tissue masses at presentation. On CT, the lesions demonstrated heterogeneous to homogeneous to centrally necrotic enhancement; on MRI, the lesions were T1 hypointense to isointense and T2 hypointense to hyperintense. Twelve of the 15 recurrent tumors with available preoperative imaging had an enhancing appearance similar to that of the original tumor. Thirteen of the 17 recurrent tumors were at the margin of a flap placed for reconstruction; the other 4 lesions were remote from the operative site. CONCLUSION: Recurrent tumors following orbital exenteration and free flap reconstruction demonstrate a wide range of imaging appearances but most often appear as a soft tissue masses often similar in appearance to the primary tumor and arising near the flap margin. Awareness of the imaging features of recurrent disease is important because failure to diagnose recurrence can delay appropriate treatment.

MRI findings of myocutaneous and fasciocutaneous flaps used for reconstruction of orbital exenteration defects.

PURPOSE: To facilitate detection of tumor recurrence, the authors reviewed the MRI characteristics of myocutaneous and fasciocutaneous free flaps following orbital exenteration for treatment of orbital or maxillofacial tumors. METHODS: The authors retrospectively reviewed the MRI characteristics, including T1 and T2 signal intensity, and enhancement pattern of 28 such flaps. RESULTS: The study included 17 myocutaneous flaps and 11 fasciocutaneous flaps placed in 28 patients. For 23 flaps, additional imaging was performed after baseline imaging (range, 2-65 months after surgery). On precontrast T1 imaging, 15 of 17 myocutaneous flaps demonstrated a striated appearance similar to that of native muscle. Twenty-six of the 28 flaps in the series were T2 hyperintense. On baseline imaging, 26 flaps showed linear (n = 5), patchy (n = 10), or homogeneous (n = 11) enhancement. No flaps demonstrated mass-like enhancement. Five fasciocutaneous and 5 myocutaneous flaps showed decreased enhancement on follow-up imaging, while 4 myocutaneous flaps showed increased enhancement. Fourteen patients received postoperative radiation, 4 of which demonstrated increased enhancement, which subsequently decreased in 3 flaps. Fourteen of 23 followed flaps became smaller over time. CONCLUSIONS: On MRI, both myocutaneous and fasciocutaneous flaps placed after orbital exenteration generally demonstrate persistent non-mass-like enhancement and T2 hyperintensity, and both types of flaps may become smaller over time. Head and neck radiologists, ophthalmologic and plastic surgeons, and oncologists should be aware of the range of imaging features of these flaps to avoid misinterpreting the postoperative appearance as tumor recurrence.

Molecular signatures of anti-nuclear antibodies--contribution of heavy chain framework residues.

It is clear that besides the CDR residues, framework residues (particularly those on FR1 and FR3) can contribute towards antigen reactivity. This study was designed to compare the immunoglobulin heavy chain FR regions of anti-nuclear antibodies (comprised of 142 anti-ssDNA, 103 anti-dsDNA and 23 anti-nucleosome Abs) with those of non-nuclear antibodies (N=165), all drawn from the GenBank. The anti-nuclear antibodies depicted residue-usage differences that reached statistical significance in their FR1 (at H1 and H29), FR2 (at H40), and FR3 (at H69, H73, H76, H80 and H87) regions. Interestingly, these residue-usage differences were intimately linked to differences in the usage frequencies of different V(H) germline genes between the different groups of antibodies; thus, whereas J558.4, J558.47, J558.m, and 7183.9 germline genes were over-utilized among the ANAs, J558.17, V130, V(H) 36-60 and VGk1a were over-represented among the non-ANAs. In conclusion, although the framework regions of ANAs exhibited distinctly different residue-usage patterns, they may simply be markers of associated germline-encoded CDR differences that appear to have been co-selected. Further studies are warranted to ascertain if any of the observed framework residue differences do actually contribute to nuclear antigen reactivity.