[1133] Incidental Pelvic Lymph Node Lymphangioleiomyomatosis in Women Undergoing Cancer Staging Surgery

Brandie Firetag, Ankur Sangoi, Charles Zaloudek, Joseph T Rabban. University of California, San Francisco, San Francisco, CA; El Camino Hospital, Mountain View, CA

Background: Lymphangioleiomyomatosis (LAM) typically presents as a pulmonary disease in premenopausal women; it may be sporadic or associated with tuberous sclerosis complex (TSC). Rare cases of extrapulmonary LAM have been reported, including lymph node involvement. We report clinico-pathologic features of incidental LAM arising within pelvic lymph nodes removed for cancer staging and its distinction from metastatic cancer.
Design: Patients with extrapulmonary LAM were identified from a search of our pathology database from 1997-2011, with an emphasis on cases with intranodal involvement (LN LAM). Clinical and radiologic data was collected from electronic medical records. Histologic slides were reviewed. Immunohistochemical staining for melanocytic (HMB45) and myoid (desmin and/or smooth muscle actin) markers was performed.
Results: 14 patients had pelvic LN LAM, 13 of whom had no prior diagnosis of TSC or LAM (pulmonary or extrapulmonary). Of these 13 patients, 9 were post-menopausal and 4 pre-menopausal (age range: 39 to 70 years). Surgical indications included: endometrial adenocarcinoma (n=6), cervical squamous cell carcinoma (n=3), ovarian serous or clear cell carcinoma (n=2), ovarian mucinous borderline tumor (n=1), urinary bladder carcinoma (n=1). Among 8 patients with follow-up, none had other TSC lesions by radiographic or clinical report. One patient had LAM within the myometrium. Histologically, the lesions were fascicular proliferations of bland spindle cells with mildly enlarged oval nuclei and flocculent or foamy cytoplasm. Lesion size ranged from 1mm to 17mm. Mitoses were rare (0-1 per 10 high power fields). Multiple LNs, up to 6 total, were involved in 6 patients and 2 had bilateral pelvic LN involved. Metastatic carcinoma to pelvic LN was present in 2 patients and LAM co-existed in the same LN as the metastates but the morphologic and cytologic features were distinct. Intranodal endosalpingiosis co-existed with LAM in 1 patient. Immunohistochemical expression of myoid markers was present in 12/12 cases and HMB45 in 11/12. In the 1 patient with known TSC, that diagnosis preceded the finding of pelvic LN LAM.
Conclusions: Intranodal LAM can be found incidentally during staging surgery for gynecologic or urologic cancer. Unlike pulmonary LAM, most LN LAM occurs post-menopausally. The distinct morphology, lack of atypia or mitotic activity and myoid/melanocytic immunophenotype helps to distinguish intranodal LAM from nodal metastases of the malignancies which prompted nodal dissection.
Category: Gynecologic & Obstetrics

Monday, March 19, 2012 9:30 AM

Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 193, Monday Morning

 

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