title: Localized retroperitoneal lymphangioleiomyomatosis mimicking malignancy. A case report and review of the literature.
abstract: Lymphangioleiomyomatosis (lymphangiomyomatosis [LAM]), a rare disease of unknown etiology that is seen only in women usually in the reproductive period, generally presents with features of pulmonary involvement. Extrapulmonary involvement, such as angiomyolipomas and retroperitoneal adenopathy, can occur in up to 75% of cases. It is very rare, however, for patients to present with features of extrapulmonary LAM. We present an unusual, localized case of LAM presenting with neurologic symptoms related to a retroperitoneal mass in a 51-year-old woman. Magnetic resonance imaging showed that the mass involved retroperitoneal lymph nodes, and a clinical diagnosis of atypical sarcoma (possibly from a uterine primary) was made. The mass was resected, and a total abdominal hysterectomy was performed. On pathologic examination, the mass showed classic histologic features of LAM with spread along lymphatic channels in the lymph nodes. Intralymphatic projections simulated lymphatic metastasis; however, the cytologic features were benign. Immunostains revealed the tumor to be positive for smooth muscle actin and desmin, but negative for HMB-45. The uterus was unremarkable, except for a subserosal leiomyoma. Although intratumoral variability for HMB-45 has recently been described, to the best of our knowledge, this is the first documented case of HMB-45-negative, histologically classic LAM. Because of the presence of several atypical features in this case, such as age, location, compressive neurologic presentation, radiologic impression of atypical sarcoma, and HMB-45 negativity, we feel that this case may represent a distinct, as yet uncharacterized variant of LAM.
authors.affiliation: Department of Pathology, University of Texas Southwestern Medical Center, Dallas 75390-9073, USA.
authors.forename: Vilkesh R
authors.initials: VR
authors.lastname: Jaiswal
authors.forename: Julie
authors.initials: J
authors.lastname: Baird
authors.forename: Jason
authors.initials: J
authors.lastname: Fleming
authors.forename: David Scott
authors.initials: DS
authors.lastname: Miller
authors.forename: Suash
authors.initials: S
authors.lastname: Sharma
authors.forename: Kyle
authors.initials: K
authors.lastname: Molberg
mesh_terms: D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007889:Leiomyoma / Q000175:diagnosis; D007890:Leiomyosarcoma / Q000175:diagnosis; D018192:Lymphangioleiomyomatosis / Q000175:diagnosis*; D008875:Middle Aged; D019042:Muscle Neoplasms / Q000175:diagnosis; D009131:Muscle, Smooth, Vascular / Q000473:pathology; D012186:Retroperitoneal Neoplasms / Q000175:diagnosis*; D012983:Soft Tissue Neoplasms / Q000175:diagnosis