Acute cutaneous methotrexate toxicity and severe pancytopenia following methotrexate prophylactic chemotherapy for the prevention of post molar gestational trophoblastic neoplasia-a case report

Gestational Trophoblastic Neoplasia is a type of malignancy that develops from a molar gestation and occurs when trophoblastic activity remains following evacuation. Evacuation of retained products of conception is the cornerstone in the management of molar pregnancies however, a subset of patients is at risk to develop post-molar gestational trophoblastic neoplasia. Chemoprophylaxis has been controversial and varies across the guidelines set by local societies. In the Philippines, methotrexate chemoprophylaxis is acceptable for patients who are at high risk developing post molar gestational trophoblastic neoplasia and when post-evacuation surveillance is doubtful. We present a 35-year-old gravid patient who was diagnosed with a partial molar pregnancy who underwent methotrexate chemoprophylaxis after suction curettage. The patient was a candidate for chemoprophylaxis since her baseline B-HCG level was elevated to 1,270,300 mIU/ml. 0.8 ml of methotrexate was given intramuscularly on alternating deltoids for 5 doses on 5 consecutive days. The patient was sent home stable with no complaints after her fifth dose however 5 days after her discharge, the patient presented in our emergency room due to pruritic skin lesions. There were multiple, well-defined, irregularly shaped erythematous to violaceous plaques with whitish scales, some with areas of erosions on the forehead, neck, back, inframammary area, abdomen, periumbilical region, bilateral upper arms, buttocks and lower extremities. Blood work up also revealed severe pancytopenia. Aggressive hydration, urine alkalinization, leucovorin rescue therapy, administration of granulocyte macrophage colony stimulating factor, and transfusion of blood products were strategies done for the successful management of the case. Although rare, the development of severe pancytopenia following MTX-administration is linked to a high incidence of morbidity and mortality and must be treated with the highest-level of care. Clearance of methotrexate from the bloodstream, folinic acid therapy, and organ treatment are 3 cornerstones in the management of methotrexate toxicity.