Perivascular epithelioid cell (PEC) tumors of the uterus: a clinicopathologic study of two cases with aggressive features

Abstract

We report the clinicopathologic, immunohistochemical and ultrastructural features of two unusual tumors of the uterus composed of spindle and epithelioid cells strongly positive for HMB45. The two patients of 56 and 48 years of age had, respectively, hemoperitoneum and abnormal uterine bleeding. Morphologically, both tumors showed atypia and extensive necrosis. The neoplastic cells express immunohistochemically both melanogenesis (HMB45) and smooth muscle markers (actin). Ultrastructural analysis showed the presence of intracytoplasmic membrane-bound granules. We viewed these neoplasms as perivascular epithelioid cell (PEC) tumors with aggressive features. Follow-up has shown the death of one patient whereas the other is alive without disease 36 months after the surgery. The two patients were evaluated for signs of tuberous sclerosis complex, and findings were negative.

Hormonal Manipulation with Letrozole in the Treatment of Metastatic Malignant pecoma

“…However, this therapeutic approach has not been widely reported or attempted in cases of pecoma. In fact, only a single case report has detailed the use of hormone manipulation in the management of malignant pecoma in the adjuvant setting, where response could not be documented 13 .…”

Predicting the Behavior of Perivascular Epithelioid Cell Tumors of the Uterine Corpus

“…[13][14][15][16][17][18][19][20][22][23][24] Also, nodules with a submucosal localization can present clinically as pedunculated or sessile polyps (Figure 1, A). Most tumors are bulky, ranging from 5 to 30 cm in greatest dimension, with mean and median sizes of 11 and 12.5 cm, respectively ( Table 2).…”

“…Most patients have long-standing abdominal pain and vaginal bleeding, but a case with an acute presentation due to uterine rupture has also been documented. 19 Most lesions are initially diagnosed by ultrasonography, usually followed by computed tomography or magnetic resonance imaging to evaluate the anatomic extent of the disease. 14,15,[18][19][20]23,24 Although intraperitoneal implants are often found at the time of initial diagnosis, distant metastases are most commonly encountered during follow-up.…”

“…19 Most lesions are initially diagnosed by ultrasonography, usually followed by computed tomography or magnetic resonance imaging to evaluate the anatomic extent of the disease. 14,15,[18][19][20]23,24 Although intraperitoneal implants are often found at the time of initial diagnosis, distant metastases are most commonly encountered during follow-up. 13,14,18,23 For those cases that show localized disease at presentation, the time to distant metastasis seems to be widely variable, ranging from 1 month to 15 years, with median and mean times to distant metastasis of 90 and 51.2 months, respectively.…”

“…[13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] Perivascular epithelioid cell tumors of the uterine corpus can occur in women of any age, including prepubertal pediatric patients. 20 While 5% of all uterine PEComas occur in the context of tuberous sclerosis, most tumors seem to be sporadic.…”