$re = '/((anticorpi|ac|ciroza).*?)?(hepatita (cr(onica)? )?(.*?))?(vh|hv|virus )([bcd])(.*?(vh|hv|virus )([bcd]))?/i';
$str = 'HEPATITA CRONICA CU VHC
HEPATITA CRONICA - VHC
HEPATITA CRONICA DE ETIOLOGIE MIXTA NUTRITIONALA SI VHC
HEPATITA CRONICA CU VHC.
HEPATITA CRONICA CU VHC.
HEPATITA CRONICA CU VHC
HEPATITA CRONICA - VHB
HEPATITA CRONICA CU VIRUS C
HEPATITA CRONICA
HEPATITA CRONICA CU VHB
HEPATITA CRONICA MEDICAMENTOASA.
HEPATITA DE ETIOLOGIE POSIBIL VIRALA IN APP
HEPATITA VIRUS C
HEPATITA CRONICA CU VHB
HEPATITA CRONICA CU VHC
Hepatita cr cu virus B
HEPATITA VIRUS C
HEPATITA VIRALA (VHA-####)
HEPATITA CRONICA VHB
HEPATITA CRONICA CU VHC
HEPATITA CRONICA- VHB
HEPATITA CRONICA CU VHC
HEPATITA CRONICA CU VHC(####)
HEPATITA CRONICA DE ETIOLOGIE NEPRECIZATA
HEPATITA CRONICA CU VHB
HEPATITA CRONICA VHC
HEPATITA CRONICA VIRALA CU VHC
HEPATITA VIRALA -VHC
HEPATITA CRONICA CU VHC
Hepatita cronica cu virus B
HEPATITA CRONICA CU VHB +VHC
HEPATITA CRONICA VHB+VHC
HEPATITA VIRALA C
HEPATITA CRONICA CU VHC
HEPATITA CRONICA CU VHB
HEPATITA CRONICA VHB+VHC
HEPATITA CRONICA CU VHB
HEPATITA B
Hepatita cronica.
HEPATITA CRONICA CU VHB
CIROZA HEPATICA SECUNDARA INFECTIEI CU VHB SI VHD
CIROZA HEPATICA VHB +VHD
CIROZA HEPATICA SECUNDARA INFECTIEI CU VHB SI VHD
HVB, HVC
HVB+ HVC
HVC + HVB
HEPATITA CU HVC
HEPATITA CRONICA HVC
HEPATITA CU HVC
CIROZA HEPATICA -HVC CHILD A
Ac AntiHVC +, HEPATOSPLENOMEGALIE
HEPATITA CU HVC
HEPATITA CRONICA HVC
ANTICORPI ANTI-HVC+
';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php