Metastatic Adenocarcinoma to the Breast arising from a Mediastinal Mature Teratoma with Somatic Malignancy: A Case Report with a Review of the Literature

Abstract

Background Malignant transformation in mature teratomas, especially somatic-type malignancies, are extremely rare phenomena with few cases described in the literature. In the mediastinum, these lesions are often accompanied by metastases, ultimately unmasking them. Case presentation We report an exceptional case of metastatic adenocarcinoma to the breast arising from a mediastinal mature teratoma with malignant transformation in a 31-year-old female. The patient initially presented with a breast lesion that was later diagnosed as either a triple negative ductal carcinoma or a metastatic adenocarcinoma of unknown origin. Extensive clinical workup and radiological imagining revealed an anterior mediastinal mass. Subsequent pathological examination of the mass showed a mature teratoma with malignant transformation equivalent to that found in the breast biopsy. Conclusion Mediastinal teratomas with malignant transformation (TMTs) are rare entities; however these tumors should be suspected in cases of suspicious mediastinal masses presenting with unusual clinical and radiological signs, such as metastasis of unknown primary origin. Pathological corroboration of extensive sampling and meticulous microscopic examination is crucial for the diagnosis in order to tailor subsequent treatment.

Retroperitoneal teratoma with malignant somatic transformation: Tumor within a tumor

“…But according to few studies the outcome of the patient is said to be improved based on the adapted targeted chemotherapy pertaining to the somatic malignant component. 9 To conclude, TMT in a primary retroperitoneal tumor is extremely rare and such a possibility should always be excluded specially in a middle aged patient with a large sized long standing tumor. It is imperative to do postoperative pathological examination i.e meticulous sampling and microscopy for accurate diagnosis of TMT as it is not always possible to predict the malignant component in teratoma, clinico-radiologically.…”

“…The former is presumed to develop due to decrease in the teratoma itself as a result of aging and hence seen usually in elderly age group with a longer duration whereas the latter is seen in relatively younger age group since after therapy, the totipotent fetal cells give rise to malignant component. 1,8,9 TMTs are commonly seen in the age group of 30-70years; the size of >9.9cm, duration of disease being the risk factors. 3 The case in discussion is a 25-yearold female with a tumor of size 11.5cms.…”

“…These tumors can be suspected on radiology with the findings of voluminous tumor with adhesion to adjacent structures, contrast enhancing capsule with thickened wall, uneven internal surface, containing fat-less solid areas. 9 It is imperative to grossly identify such suspicious areas which may exist only in a part of the specimen and may appear as mural plaque/ mural nodule/ polypoidal mass/ solid areas/ as a necrotic or hemorrhagic area.…”

“…Any constituent of the teratoma has potential for malignant change. The malignant component can be carcinomatous like squamous cell carcinoma, adenocarcinoma, etc which is seen in around 37% of the germ cell tumours with somatic type malignancy; 9 with the former being most common type. Mucinous, enteric, intestinal, signet ring cell type variants of adenocarcinoma have been documented.…”

“…TMTs have metastatic potential. 3,9 Lymph node, scalp, breast and brain metastasis have been reported. 6,9,10 The present case showed bilateral lung metastases.…”