 pneumocysti carinii pneumonia case studi electron microscopi paper deal clinicopatholog find 2 patient pneumocysti carinii pneumonia exampl 51 2-month-old white femal infant underli diseas second occur associ cytomegal inclus diseas lung 46-year-old white woman receiv steroid therapi cytotox agent irradi thorax hodgkin's diseas electron microscop studi morpholog organ tissu remov autopsi 