Cerebrotendinous xanthomatosis
A 20-year-old male studying 8th standard presented with complaints of slowly progressive swellings over the left forearm, front of left knee, and behind the ankles bilaterally [Figure , ] for last 10 years. The swellings were painless, but of late, he experienced pain in front of the left knee while squatting and on prolonged walk.\nHe had similar swelling on the left forearm 5 years ago which recurred 1 year after surgery. He was operated for bilateral congenital cataracts at the age of five. He also had delayed milestones and decreased scholastic aptitude. He was taking Phenytoin before presentation for recurrent seizures. He was the third child born out of consanguineous marriage, others being normal.\nOn examination, he had short stature, bilateral pes cavus deformity, swellings of various sizes located near the ulnar border of left forearm, left infrapatellar region in the patellar tendon, and fusiform swellings bilaterally along the tendoachilles. The largest measured swelling was of 14 × 6 cm in the right tendoachilles. Terminal degree of flexion of left knee was restricted and painful with full range of motion at all other joints. Neurological examination revealed a decreased IQ (55). He also had bilaterally decreased muscle bulk with Grade 4 muscle power. Sensory system examination was normal. He had bilateral brisk reflexes with minimal cerebellar ataxia.\nHis renal and liver function tests, calcium, phosphorous, alkaline phosphatase levels, and fasting lipid profile were within normal limits. His complete blood picture and peripheral smear did not reveal any abnormality. Nerve conduction studies were normal. EEG showed diffuse slow wave activity with intermittent discharges at varied places. Magnetic Resonance Imaging (MRI) of the brain revealed minimal cerebral and cerebellar atrophy. MRI of both the ankles showed diffuse enlargement of bilateral tendoachilles and features of increased signal intensity in T1, T2 image sequences [Figure –] demonstrative of lipid deposits at their calcaneal attachments.\nHe underwent excision biopsy of swelling within the left patellar tendon [Figure , ]. Histopathologic examination of the specimen revealed foamy histiocytes, areas of fibrosis with plenty of cholesterol clefts, many foreign body and touton type of giant cells, and focal sparse chronic inflammatory cell collection. The features were suggestive of tendinous xanthomatosis []. He was started on chenodeoxycholic acid (CDCA) 250 mg TDS and atorvastatin 20 mg at HS daily and phenytoin was continued at 100 mg TDS. Patient was reviewed after an year, and on examination, he had developed new xanthomas on the chest wall over the ribs and there was minimal increase in the size of other xanthomas as he was noncompliant for treatment. Patient was counseled and his relatives were advised the need for regular treatment and followup.