An unusual oral mass

PA Sathe, RK Ghodke, BM Kandalkar 
 Department of Pathology, Seth G. S. Medical College, Mumbai, Maharashtra, India

Correspondence Address:
P A Sathe
Department of Pathology, Seth G. S. Medical College, Mumbai, Maharashtra
India

Full Text

A 2-day-old full term baby was referred to our hospital after an uneventful delivery for a large mass attached to the middle portion of the lower lip. Prenatal investigations were not done. The general examination did not reveal any abnormality. Respiratory system examination showed an increased respiratory rate with signs of respiratory distress. Local examination showed a large, irregular soft tissue mass measuring 15Χ10 cm adherent to the middle one-third of the lower lip, floor of the mouth, and the tongue. Middle one third of the mandible was deficient. Clinical impression was facial teratoma. The hematological parameters were normal. Serum beta human chorionic gonadotropin (b HCG) level was assessed as a tumor marker for teratoma and it was in the normal range. Serum alpha feto protein (AFP) level was 1,65,000 μg/L. Roentgenogram (X-ray) of the mass showed multiple calcifications and a well-formed corticated structure. Computed tomography (CT) showed a solid-cystic mass with multiple calcifications and ossifications [Figure 1] resembling dysplastic vertebrae and well-formed bones. Due to the presence of dysplastic vertebrae and well-formed bones with spatial organization of tissues around it, the radiological impression of fetus in fetu (FIF) was favored over teratoma. The patient was anesthetized by oral intubation and the mass was surgically excised.

On excision, an irregular skin covered mass weighing 300 g and resembling a fetus was received. Externally it showed rudimentary limbs and a head like structure with hair [Figure 1]. Cut surface showed skin and subcutaneous fat at the periphery. Cystic, soft, bony, cartilaginous areas, and an intestine like structure were identified. Microscopy showed fully differentiated choroid plexus, respiratory tract, small intestine, vas deferens, epididymis, lymphoid tissue, neural tissue, bone, and cartilage [Figure 2]. Histopathology diagnosis was FIF.{Figure 1}{Figure 2}

Postoperatively, baby needed mechanical ventilation for respiratory distress. Clinical reassessment, chest roentgenogram, and electrocardiogram suggested a possibility of ventricular septal defect with left to right shunt. The baby succumbed on the 18 th post-operative day despite adequate treatment. Cause of death was given as full-term neonate with congenital heart disease in congestive cardiac failure and the death did not seem to be related to anesthetic complications. FIF is a rare condition associated with abnormal embryogenesis. [1] Fewer than 100 cases of FIF have been reported worldwide. [1] The most common location is the retroperitoneum (seen in 70% cases). Oral cavity is an extremely rare site. [1] A majority of the cases occur during infancy. [1],[2] The patient may have symptoms of mass effect like our patient who had respiratory distress. [3] There is controversy as to whether FIF is a distinct entity or a highly organized teratoma. [4] The commoner theory is that it is a highly organized teratoma. On imaging, the presence of a vertebral column seen in up to 50% of FIF is an important feature that distinguishes it from a teratoma. [1],[2] However, inability to visualize a well-formed vertebral axis as seen in our case may occur due to an under-developed and markedly dysplastic spinal column. [5] Fetiform teratoma and an epignathus are rare teratomas, the former occurring in the ovary and the latter in oral cavity. These can resemble FIF if they are highly differentiated. The absence of well-formed complex fully developed organs, the absence of segmental axial skeleton, organization of tissues resembling a human body, and zygosity differentiates them from FIF. Another theory for the development of FIF is that of a parasitic twin wherein the enveloped twin becomes a parasite and is dependent for its existence on the surviving twins (the autosite) to which it is attached. [1],[3]

Serum AFP levels were high in our case, but they may also be normal. [2] Complete excision is curative. However clinical, radiological, and serological (AFP) follow-up is recommended as occasional cases have recurred. [4]

Diagnosis of FIF needs pathology confirmation and should be considered even at a rare site like oral cavity. Only one case presenting as a protruding oral mass has been previously reported to the best of our knowledge. [3] Hence, we thought it was worthwhile reporting this rare case.

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