We report the association of gigantomastia during pregnancy and a lactating adenoma in ectopic breast tissue of the vulva in a context of myasthenia in a 27-year-old primigravid woman. We discuss the pathophysiologic condition and management of gigantomastia that involves ectopic breast tissue during pregnancy.
Gigantomastia during pregnancy is a rare disorder that is characterized by diffuse, extreme, and incapacitating breast hypertrophy. Its underlying mechanisms remain unclear. The association of gigantomastia and autoimmune diseases, such as myasthenia, has been reported. Diseases of breast ectopic tissues have been described for many years. However, involvement of the vulva has never been described in cases of gigantomastia. We report a case of gigantomastia with myasthenia during pregnancy with development of a vulvar lactating adenoma.
Case Report
We report the case of a 27-year-old primigravid woman with enlargement of both breasts at 18 weeks of gestation. She had been diagnosed with myasthenia 6 years before. Breast volume continued to increase until the seventh month of pregnancy ( Figure 1 ). Magnetic resonance imaging showed symmetric breast enlargement, with no remarkable features ( Figure 2 ). Microbiopsy at 32 weeks of gestation revealed dystrophic mammary tissue with lobular hyperplasia.
Repeated blood cell count, blood electrolytes, C-reactive protein, liver enzyme values, and thyroid function tests were normal. Hormone levels were in accordance with pregnancy. Antibodies for acetylcholine receptors were positive. Rheumatoid factors on the latex agglutination test and antinuclear antibodies were negative. Antineutrophil cytoplasmic antibodies on indirect immunofluorescence were negative, as were anticardiolipid and antithyroid antibodies.
During the seventh month of pregnancy, a 5-cm vulvar tumor appeared. It was a homogenous pedunculated mass of the left labia majora that was distant from the external anal sphincter on the magnetic resonance imaging scan ( Figure 3 ). Considering the benign appearance of the vulvar mass and because of the risk of hemorrhage, we decided not to perform surgery or biopsy. To control tumor volume and reduce pain, at 35 weeks of gestation, oral corticotherapy (prednisone) at the dose of 0.5 mg/kg/d was initiated and given until the delivery, with stepwise dose reduction. Breast volume and pain were controlled; at the end of pregnancy, the vulvar mass measured 10 cm ( Figure 4 ).
