Unusual Imaging Findings Associated with Germ Cell Tumors

Abstract

Germ cell tumors, because they contain immature and mature elements, can differentiate into different tissue types. They can exhibit unusual imaging features or manifest in a syndromic fashion. The authors describe these features and assign them to one of the following categories: (a) unusual manifestations of metastatic disease (growing teratoma syndrome, choriocarcinoma syndrome, ossified metastases, and gliomatosis peritonei); (b) autoimmune manifestations (sarcoidlike reaction and paraneoplastic syndromes); (c) endocrine syndromes (sex hormone production, struma ovarii, and struma carcinoid); or (d) miscellaneous conditions (ruptured dermoid cyst, squamous cell carcinoma arising from a mature teratoma, Currarino triad, fetus in fetu, pseudo-Meigs syndrome, and pancreatitis). Rare conditions associated with germ cell tumors demonstrate characteristic imaging findings that can help lead to the appropriate diagnosis and management recommendations. When evaluating for potential metastatic disease, alternative benign diagnoses should be considered (eg, growing teratoma syndrome, ossified metastases, ruptured dermoid cyst, gliomatosis peritonei, and sarcoidlike reaction), which may impact management. Germ cell tumors may also lead to life-threatening complications such as extensive hemorrhage from choriocarcinoma metastases or the rupture of mature teratomas, cases in which timely diagnosis is crucial. Autoimmune and endocrine manifestations such as paraneoplastic encephalitis, autoimmune hemolytic anemia, and hyperthyroidism may occur owing to the presence of germ cell tumors and can create a diagnostic dilemma for clinicians. Knowledge of the syndromic and unusual imaging findings associated with germ cell tumors helps guide appropriate management. ©

Human chorionic gonadotropin elevation in gliomatosis peritonei complicated with immature teratoma: A case report and review of the literature

“…[ 30 ] Another theory proposes that the glia is differentiated from tumor cells in the ovarian immature teratoma. [ 3 , 31 ] The macrophage-derived factors could allow the neural component of ovarian teratoma to implant in the peritoneal cavity and induce astroglial differentiation, which could explain why the peritoneal implants are mostly mature even when they originate from immature teratomas. [ 32 ] The detailed information of peritoneal gliomatosis remain to be determined.…”

Ovarian Teratomas: A Spectrum of Disease. An approximation for radiologists in training

“…With ovarian necrosis, there is no contrast enhancement or minimal or no arterial or venous flow on US 11,16 [Figure 11] The uncommon complication (1-4%) of MCT is rupture 3 . Rupture can occur spontaneously or after ovarian torsion 18 . On CT, rupture is evident with the distortion of the mass contour, lack of wall continuity, and free fluid with free fat cells 18 .…”

“…Rupture can occur spontaneously or after ovarian torsion 18 . On CT, rupture is evident with the distortion of the mass contour, lack of wall continuity, and free fluid with free fat cells 18 . As a result, rupture causes acute peritonitis.…”

Metastatic testicular choriocarcinoma to the rectum requiring diverting colostomy

“…The large rectal mass may have developed from a direct metastasis or local invasion from a malignant pelvic lymph node. Choriocarcinoma is known to metastasize early to locations including liver, lung and brain, 3,4 and there are a number of case reports detailing unusual lesions in skin, stomach and spleen 5–7 . Gastrointestinal metastases are uncommon, with colonic or rectal lesions rarely reported 8,9 .…”