TY - JOUR
T1 - Micronodular pneumocyte hyperplasia
AU - Muir, Trudie E.
AU - Leslie, Kevin O.
AU - Popper, Helmut
AU - Kitaichi, Masanori
AU - Gagné, Eric
AU - Emelin, Jessica K.
AU - Vinters, Harry V.
AU - Colby, Thomas V.
PY - 1998
Y1 - 1998
N2 - Tuberous sclerosis complex (TSC) is an autosomal-dominant disorder characterized by mental retardation, seizures, and central nervous system and visceral hamartomas. Pulmonary involvement manifesting as lymphagioleiomyomatosis (LAM) occurs in 1% of patients (all women) with TSC. Micronodular pneumocyte hyperplasia also has been described as a rare pulmonary manifestation of TSC. We report 14 patients with micronodular pneumocyte hyperplasia (MNPH). The patients ranged in age from 23 to 57 years (mean 37.5). There were 12 women and 2 men. Nine of the patients (one man and eight women) had documented clinical manifestations of TSC: seven with LAM, two without LAM (including one man). Of the five patients who did not have TSC, three had LAM and two did not (including one man). Histologically, all 14 cases demonstrated multiple well-demarcated nodules usually measuring up to 8 mm in size, but most were 1-3 mm. The nodules were produced by a proliferation of enlarged cytologically benign type II pneumocytes, with an associated increase in alveolar macrophages and interstitial reticulin. Immunoperoxidase studies showed the type II pneumocytes within lesions to be reactive with antibodies to cytokeratin (four of four), epithelial membrane antigen (EMA) (five of five), and surfactant apoprotein B (8 of 10). HMB-45 was negative in the MNPH lesions in all nine case studied. Follow-up was available in 9 of 10 living patients and ranged from 1 to 14 years (mean 6 years). Nine patients are alive; six are clinically stable and three have repeated pneumothoraces related to LAM. Four patients have died. None of the deaths were attributable to MNPH. MNPH appears to be a hamartomatous proliferation occurring most frequently in patients with tuberous sclerosis, is separable from and not a manifestation of LAM, has been observed to occur in men, and, like other hamartomas of tuberous sclerosis, does not appear to possess malignant potential.
AB - Tuberous sclerosis complex (TSC) is an autosomal-dominant disorder characterized by mental retardation, seizures, and central nervous system and visceral hamartomas. Pulmonary involvement manifesting as lymphagioleiomyomatosis (LAM) occurs in 1% of patients (all women) with TSC. Micronodular pneumocyte hyperplasia also has been described as a rare pulmonary manifestation of TSC. We report 14 patients with micronodular pneumocyte hyperplasia (MNPH). The patients ranged in age from 23 to 57 years (mean 37.5). There were 12 women and 2 men. Nine of the patients (one man and eight women) had documented clinical manifestations of TSC: seven with LAM, two without LAM (including one man). Of the five patients who did not have TSC, three had LAM and two did not (including one man). Histologically, all 14 cases demonstrated multiple well-demarcated nodules usually measuring up to 8 mm in size, but most were 1-3 mm. The nodules were produced by a proliferation of enlarged cytologically benign type II pneumocytes, with an associated increase in alveolar macrophages and interstitial reticulin. Immunoperoxidase studies showed the type II pneumocytes within lesions to be reactive with antibodies to cytokeratin (four of four), epithelial membrane antigen (EMA) (five of five), and surfactant apoprotein B (8 of 10). HMB-45 was negative in the MNPH lesions in all nine case studied. Follow-up was available in 9 of 10 living patients and ranged from 1 to 14 years (mean 6 years). Nine patients are alive; six are clinically stable and three have repeated pneumothoraces related to LAM. Four patients have died. None of the deaths were attributable to MNPH. MNPH appears to be a hamartomatous proliferation occurring most frequently in patients with tuberous sclerosis, is separable from and not a manifestation of LAM, has been observed to occur in men, and, like other hamartomas of tuberous sclerosis, does not appear to possess malignant potential.
KW - Micronodular pneumocyte hyperplasia
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U2 - 10.1097/00000478-199804000-00012
DO - 10.1097/00000478-199804000-00012
M3 - Article
C2 - 9537475
AN - SCOPUS:0031966315
SN - 0147-5185
VL - 22
SP - 465
EP - 472
JO - American Journal of Surgical Pathology
JF - American Journal of Surgical Pathology
IS - 4
ER -